6 p. : ill. ; 24 cm.Includes bibliographical references

Day Roraima Expedition of the American Museum of Natural History (1927-1928)

Needham, James G. (James George), 1868-1956.

Tate, G. H. H. (George Henry Hamilton), 1894-1953.

Tyler Duida Expedition of the American Museum of Natural History (1928-1929)

American Museum of Natural History Scientific Publications

AMERICAN MUSEUM NOVITATESPublished byNumber 664 Twe AmERicAN Muszum oNATURAL HISTORY Sept. 30, 193359.57,33 (87)DRAGONFLIES FROM MT. DUIDA AND THE VENEZUELANBORDERBY JAMES G. NEEDHAMA small collection of pinned dragonflies from the Venezuelan borderand adjacent parts of Brazil, sent to me for determination by The Ameri-can Museum of Natural History, contains some interesting new material.Not all of it is specifically determinable, for some of the specimens aretenerals and many are broken. Among the whole ones, however, incondition fit for description, there are specimens representing one newgenus and two new species. A list of species by localities follows, withdescriptions of the new forms given at its close.MT. DUIDAOrthemis ferruginea Fabricius.-A single male, October 27, 1926.Zenithoptera americana Tjinnaeus.-One female, March 7, 1929; amale, October 10, 1928.Erythrodiplax umbrata Linnaeus.-One male, October 27, 1928.Ephidatia batesii Ris.-One female, October 21, 1928.Mecistogaster linearis Fabricius.-One male, November 23, 1928.Dimeragrion secundum, new species.-Two males, December 8, 1928.Tate No. 433. See p. 5.Argia (species?).-Undeterminable fragments of apparently three species.Metaleptobasis (species?).-A single undeterminable female, December23, 1929. Tate No. 373.Acanthagrion (species?).-A single fragment of a male, December 10,1928.Rima arcana, new genus and species.-See p. 3.Aeolagrion fulvum, new species.-See p. 5.MT. RORAIMAStaurophlebia reticulata Burmeister.-A single female of very largesize (hind wing, 75 mm.), January 2, 1928.Aeschna (species?).-A single female, not certainly determinable; ofthe A. cornigera group.AMERICAN MUSEUM NOVITATESNephepeltia (species?).-A single female with the end segments of theabdomen lost, apparently near N. flavifrons, yet not agreeing withother species of the genus in certain venational characters; in thepossession in the fore wing of a half antenodal cross-vein (65; in all),in a subtriangle of two cells, in having two cross-veins behind thestigma, and in having two full cell-rows in the space beyond thetriangle. Despite these considerable differences I believe it belongsin Nephepeltia because of major agreements in form of triangles,in the origin of vein Cut from the outer side of the triangle in thefore wing, in the general disposition and number of cross-veins, andin having the radial planate subtend and definitely circumscribefour cells in the front wing and three in the hind.Orthemis ferruginea Fabricius.-One male, Paulo, 4000 feet, December17, 1927.Uracis ovipositrix Calvert.-Two females. Aribupu, altitude 4200 feet,December 20, 1927.Erythrodiplax abjecta Rambur.-One male. Philipp Swamp, altitude5000 feet, October 28, 1927. One pair, January 28, 1929.Erythrodiplax attenuata ? Kirby.-Two females.Sympetrum illotum Hagen.-One male from summit, at 8600 feet,November 24, 1927. Comes nearest the variety 'irgula of De Selysin coloration.Lais (species?).-Two undeterminable fragments from an altitude of4200 feet.Heteragrion ictericum Williamson.-One male from an altitude of 4200feet, December 26, 1927.OTHER LOCALITIESOrthemis ferruginea Fabricius.-One male from Rio Negro Brazil,February 19, 1928.Erythemis credula Hagen.-One male, September 15, 1928.Erythrodiplax attenuata Kirby.-Two males, Rio Negro Brazil, Sep-tember 24, 1928.Diastatops obscura Fabricius.-One female, Rio Casiquiare, Venezuela,September 30, 1928.Triacanthagyna septima De Selys.-Two females, Low Amazonas,April 29.Neoneura (species).-One male (fragment), Rio Negro, Brazil, September10, 1929.2 [No. 66419331 DRAGONFLIES FROM VENEZUELA AND BRAZIL 3RIMA, new genusHead broad, with low occipital ridge and with hardly any frontal prominence.Hind lobe of the prothorax produced ( 9) into a thin flat plate. Legs moderate,with spines rather few and short. Claws toothed well before the apex. Wingsstalked to near the level of the first antenodal cross-vein. Arculus a little before thesecond antenodal cross-vein, its upper piece very short, and the space between thisand the subnodus without cross-veins. Middle fork much nearer the arculus thanthe nodus. Quadrangle oblique and sharply pointed, its front side a little shorterin the fore wing and a little longer in the hind wing than the inner side. There are nocross-veins in quadrangle, subquadrangle, or in the space behind the latter. Stigmarather elongate, without brace-vein. Vein M2 parts from Ml a little beyond thesubnodus. Three rows of intercalary cells occupy the marginal interspaces immediatelybebind veins Mia, M2, Rs and M4.GENOTYPE.-Rima arcana, new species.This form is so distinct from all other known Zygoptera that I haveno hesitation in giving it a name. In venation it is nearest to the Indiangenus Megalestes. It is allied to the Neotropical Hypolestes. From bothof these it differs in the remoteness of the nodus from the arculus, and inthe more proximal origin of veing M2. It agrees with Hypolestes inlacking a brace-vein to the stigma, but further differs in having inter-calaries between veins M2 and Rs, and a more elongate stigma.The nymph of Hypolestes (if rightly identified) is, however, notlestine at all. More knowledge of the immature stages of these andallied forms is needed to establish their relationship.The name I have used, it will be observed, is that of the heroine ofWm. H. Hudson's Venezuelan novel, 'Green Mansions.'Rima arcana, new speciesLength, 41; abdomen, 30; hind wing, 30 mm.Colors dull greenish-black and brown. Head dull black above from antennaeto occiput, with a suggestion of a pair of minute pale dots between the antennae.Face yellow, with a smooth, bare and shining greenish-black labrum, and a squarishpatch of the same color on the middle of the horizontal upper surface of the post-clypeus. Jaws and labium yellow, heavily tipped with black. Rear of head black.The six segments of the black antennae are of nearly equal length, and all beyond thebasal one are very slender.Prothorax dull yellowish-brown with a black spot covering its projecting hindlobe and a small adjacent crescentic area on the middle lobe. Synthorax brown, witha wide greenish-black middle stripe that at its ends overspreads the outer angles ofcrest above and collar below in fore-and-aft symmetry. In the brown of the sidesthere are obscure darker bands in front of and bordering the three lateral sutures.The middle one is darkest, being almost black.Legs brown basally, becoming black beyond the knees. Tibial spines slightlylonger than the intervals between them; fourteen in number in the outside row on thehind tibia.AMERICAN MUSEUM NOVITATESWings hyaline with black beins and brown stigma. Postnodal cross-veins 17 to18, and 15 to 16 in fore and hind wing respectively. There is an extra half antenodalin the costal space of the left hind wing, as shown in figure 1.. Stigma 4 mm. longby 1 mm. wide; a little widened between heavy bordering black veins, about equallyacute at the ends. Behind it are six or seven cross-veins. Vein Mia approaches Miconvergently behind the stigma and is followed by three cell-rows thence to the wingFig. 1. Rima arcana, new species.Fig. 2. Dicterias procera, Selysmargin. Veins M3 and M4 diverge at the wing margin with an irregular dispositionof cells between them. Vein Cui springs forward from the apex of the quadrangle,and then for a distance runs parallel with M4. Behind veins Cul and Cu2 are singlerows of cells.Abdomen greenish black above, dull yellowish-brown beneath from end to end.The paler color rises a little higher on the sides of the basal segments. There is a washof blackish on both base and tip of the ovipositor. The tenth abdominal segment is4 [No. 6641933] DRAGONFLIES FROM VENEZUELA AND BRAZILdivided to the base by a deep mid-dorsal cleft. Cerci hardly as long as the tenth seg-ment, thick and subtriangular. The ovipositor slightly surpasses the tip of the hairyanal tubercle. Its slender declined tips are about as long as the cerci. Its lowermargin is smooth at base but very finely denticulate toward the tip.There is a single female specimen from Mt. Duida, Venezuela; January 4, 1929.Amer. Mus. accession No. 29500; Tate No. 527.With the figure of the wing of Rima, we present a drawing of Dic-terias (from the same region)-the only American agrionine genus ofwhich the venation has not hitherto been adequately figured.Dimeragrion secundum, new speciesLength, 52; abdomen, 44; hind wing, 31 mm.This is a greenish-black, yellow-faced species with very long and slender abdomen.Top of head black, this color extending forward in a stout-stemmed T-spot whoseslender top-bar lies on the frontoclypeal suture.Prothorax yellowish, black-balTed across the front margin and more narrowlyacross the thinly fringed rear margin. Synthorax greenish black with a translucentbrownish-yellow stripe before the humeral suture. Sides brownish yellow with adiffuse streak of greenish black just behind the humeral suture and a narrow blackline along the subalar carina; below, yellow. Legs blackish beyond the yellow basalsegments. There are six long spines and two close-set shorter ones in the outer rowon the hind tibia. Wings hyaline. Postnodal cross-veins 25 and 24 in fore and hindwing respectively. There is no cross-vein in the space before the anal crossing.Otherwise, very closely similar to D. percubitale as figured by Calvert, 1913, Proc.Acad. Nat. Sci. Phila., Plate xiv, figure 6, except that the veins M2 and Rs arise alittle farther forward; Rs very close to the subnodus, and M2 nearly a full cell-lengthbefore it.Abdomen blackish above and yellowish at the sides and beneath. The brown isdilated into an apical ring-band on segments 3 to 7 and there is a narrower, brighteryellow basal ring on the same segments. Segments 8 to 10 are more extensively darkbrown or blackish, the apex of 10 being wholly black. There is a black (-markon the hind margin of segment 1 at the side, and there are two similar but smaller(-marks on the rear of the metathorax just before it. Superior appendages black,paler within; inferiors brown. These are similar to those of D. percubitale as figuredby Calvert (loc. cit., Figs. 7 and 8), except that the superiors are distinctly longerthan the inferiors, and the plate that they bear internally is very much broader andprojects obliquely downward and forward in a blunt barb-like angulated recurrent lobe.The single specimen is a fairly mature male from Mt. Duida, Venezuela;December 16, 1928. Amer. Mus. accession No. 29500.This is a larger species than D. percubitale, differing in many minorpoints of coloration.Aeolagrion fulvum, new speciesLength, 42; abdomen, 35; hind wing, 22mm.This is a brownish-rufescent species having the thorax heavily striped withblack. Face rufescent up to and including the antennae. Top of head black with a5AMERICAN MUSEUM NOVITATESpair of small pale V-marks which may be enlarged and united at the middle ocellusinto a transverse yellow W-mark. The hind margin of the occiput is obscurely paler.Prothorax tawny, with three black blotches, a median one on the base of the hindlobe and two lateral ones on the sides of the middle lobe. There are also some blackdots above the coxa. Synthorax with a broad and regular black mid-dorsal stripe thatis wider than the bordering pale stripe. A fine line of brown in the depths of thehumeral suture is expanded into an oval spot near its upper end. A broad black stripecovers most of the mesepimeron, its front edge straight, its hind margin serratelynotched into three big decurrent teeth. The upper end of the third lateral suture,points on the subalar crest, and the lower hind angle of the metepimeron are narrowlytouched with black. The remainder of the sides and all of the venter are tawnyyellow.Legs uniformly reddish, with black spines and claws. Hind tibiae with sevenspines on each row, longest in the middle, the two proximal spines weaker than theothers.Wings slightly yellowish in tint, with brown veins and tawny stigma. Postnodalcross-veins about 14 and 13 mm. in fore wing and hing wing respectively.Abdomen pale reddish-fulvous, a little darker at the ends, without pattern. Thedorsal apical margin of the tenth segment is uprolled and erected in a thickened rimthat is bilobed, pale on its anterior and blackish on its posterior face. Superiorappendages of the male as long as tenth segment. Viewed from above they are atfirst subeylindric, then obliquely truncated to their divergent tips, and blackened onthe face of the truncated surface. Viewed from the side their thick ascending basalthird bears above an obtuse tubercle, after which they are suddenly narrowed, flat-tened and then tapered to a blunt black tip. The inferior appendage viewed from theside is slightly shorter than the superior, thick at the pyramidal base, then directedstraight to rearward and tapered to the black tip, which bears a low superior tooth.Viewed from beneath, beyond the stout approximated bases of the inferior pair, thetapering blunt-ended tips form a ()- shaped enclosure.The single headless female in the collection shows the same pattern as the male,with more darkening on the dorsum of the prothorax and along the dorsum of theabdomen as far as the apex of the ninth segment. The black stripes of the synthoraxare wider, but otherwise similar.In both sexes there is a thin fringe of long tawny hairs on the dorsum of thethorax and on the venter of the basal abdominal segments.Twelve males and one female; Mt. Duida, Venezuela; January 7, 1929. Amer.Mus. accession No. 29500; Tate No. 539.This species belongs to the group having the superior appendage ofthe male unbranched. It is allied to A. demerarum Williamson, but isreadily distinguished in the male by the all-red abdomen, by the uprolledand erected apex of the tenth abdominal segment, and by the form ofthe appendages.6 [No. 664

Dragonflies from Venezuela and Brazil

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