Causey, Nell B.

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Journal of the Arkansas Academy of Science Volume 4 Article 12 1951 On Eurymerodesmidae, a New Family of Diplopoda (Strongylosomidea), and a New Arkansas Species of Eurymerodesmus Nell B. Causey Follow this and additional works at: https://scholarworks.uark.edu/jaas  Part of the Entomology Commons Recommended Citation Causey, Nell B. (1951) "On Eurymerodesmidae, a New Family of Diplopoda (Strongylosomidea), and a New Arkansas Species of Eurymerodesmus," Journal of the Arkansas Academy of Science: Vol. 4 , Article 12. Available at: https://scholarworks.uark.edu/jaas/vol4/iss1/12 This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking prior permission from the publisher or the author. This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu. 69ON EURYMERODESMIDAE, A NEW FAMILY OF DIPLOPODA(STRONGYLOSOMIDEA), AND A NEW ARKANSASSPECIES OF EURYMERODESMUSNELL B.CAUSEYFayetteville, ArkansasEurymerodesmidae , fam. nov.This family is set up to include certain genera from the MississippiValley, Southeastern and Southwestern States formerly included in Xysto-desmidae, or in Chelode smidae from which it can be separated by the fol-lowing characteristics: mandibles with a tongue-like protuberance on theanterio-ventral margin of the pars basalts; unspined sternites, coxae, andprefemurs; male sternites setose, often with lobes; keels narrow to moder-ately wide; male gonopods consisting of a large basal division and a smalltelopodite which is simple, either setose or glabrous, and caudally directed;gonopodal opening of male with anterior margin always recurved medially(figure 2) and variously modified with lobes and setae, the lobes on the caudaland lateral margins. It resembles Xystodesmidae inhaving smooth tergiteswith the keels horizontal to somewhat depressed, their lateral marginsraised and not serrated.Type-genus: Eurymerodesmus Brolemann 1900. Other genera are KewaniusChamberlin 1938 and Paresmus Chamberlin 1942.Eurymerodesmus angularis, sp. nov.Figures 1-3This species resembles E. spectabilis Causey and E. bentonus Causeyin the shape of the lobes on the gonopodal opening of the male, but it canbe distinguished from both by differences in the shape of the telopodite ofthe gonopod and by the distribution of setae on it.Male holotype. Dorsum black-brown mottled with beige; mid-dorsalblack line; orange line around collum, around keels, and across tergites;pleurites dark; sternites cream; legs gray distally.Lateral margins of keels convex, but less so than in E. hispidipes(Wood). Caudal angles of keels 13 through 19 acute. Protuberance onpars basalis of mandibles relatively small, without pigment or ridges.Coxal joint of second legs with the usual two conical tubercles, the anteriorlarger. A pair of low, rounded, hirsute prominences on the metasternitebetween each pair of legs except first two and last two pairs. Metasternitebetween ninth legs 1 excavated medially as usual, the furrow narrow and thesetae no longer than those between the other legs (figure 1).These are the legs on the seventh segment directly behind the gonopods; theycorrespond in position to the ninth legs of the female.69Journal of the Arkansas Academy of Science, Vol. 4 [1951], Art. 12Published by Arkansas Academy of Science, 195170 ARKANSAS ACADEMY OF SCIENCEFIGURE 1. Eurymerodesmus angularis, caudal view of sternum between ninthlegs of male.FIGURE 2. Eurymerodesmus angularis, ventral view of gonopodal opening.FIGURE 3. Eurymerodesmus angularis, submedial view of left gonopod of male.Gonopodal opening bears posterio-laterally a pair of recurved lobes. Inlateral view the lobes appear triangular, shorter than the coxae of the ninthlegs, with the caudal surface pigmented and covered with setae and thecephalic surface without setae and dark pigment. In ventral view the lobesare seen to turn back medially; laterally they flare away from the marginand then turn in toward the bases of the ninth legs (figure 2). The marginsof the lobes are darkly pigmented and setose. A row of setae is across theposterior margin of the opening; the anterior margin was damaged, makingit impossible to determine whether there are setae there.Telopodite of gonopod (figure 3) relatively short, smoothly accuminate,and bent sharply distad. It bears three rows of setae; two rows are short,near the base, on opposite sides of the telopodite, and each is composed of12 or so setae almost as long as the telopodite; the third and longest rowis composed of shorter setae; the distal third of the telopodite is free ofsetae; at its base is a thick tuft of long setae.Length 23 mm, width 3.6 mm.A female collected with the male holotype and believed to belong tothis species agrees in general with the male but differs in the following:length 25 mm, width 3-8 mm; sternites glabrous.Locality. Arkansas, Prairie Co., De Vails Bluff. The male holotype andtwo females were collected by Mr. Le Roy Gray in April, 1950. The typespecimen will be deposited in the collection of the Academy of NaturalSciences of Philadelphia.70Journal of the Arkansas Academy of Science, Vol. 4 [1951], Art. 12https://scholarworks.uark.edu/jaas/vol4/iss1/12Of the numerous species of Eurymerodesmus , twelve are known to occurin Arkansas. Several females in my collection are believed to belong toadditional undescribed species. Systematic collecting in the state andadjoining areas would furnish interesting material for a study of speciationin this very plastic genus. A key to the Eurymerodesmidae occurring inArkansas willbe published in an early paper.7171Journal of the Arkansas Academy of Science, Vol. 4 [1951], Art. 12Published by Arkansas Academy of Science, 195172Journal of the Arkansas Academy of Science, Vol. 4 [1951], Art. 12https://scholarworks.uark.edu/jaas/vol4/iss1/12

On Eurymerodesmidae, a New Family of Diplopoda (Strongylosomidea), and a New Arkansas Species of Eurymerodesmus

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Journal of the Arkansas Academy of ScienceVolume 4 Article 121951On Eurymerodesmidae, a New Family ofDiplopoda (Strongylosomidea), and a NewArkansas Species of EurymerodesmusNell B. CauseyFollow this and additional works at: http://scholarworks.uark.edu/jaasPart of the Entomology CommonsThis article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able toread, download, copy, print, distribute, search, link to the full texts of these articles, or use them for any other lawful purpose, without asking priorpermission from the publisher or the author.This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for inclusion in Journal of the Arkansas Academyof Science by an authorized editor of ScholarWorks@UARK. For more information, please contact scholar@uark.edu, ccmiddle@uark.edu.Recommended CitationCausey, Nell B. (1951) "On Eurymerodesmidae, a New Family of Diplopoda (Strongylosomidea), and a New Arkansas Species ofEurymerodesmus," Journal of the Arkansas Academy of Science: Vol. 4 , Article 12.Available at: http://scholarworks.uark.edu/jaas/vol4/iss1/1269ON EURYMERODESMIDAE, A NEW FAMILY OF DIPLOPODA(STRONGYLOSOMIDEA), AND A NEW ARKANSASSPECIES OF EURYMERODESMUSNELL B.CAUSEYFayetteville, ArkansasEurymerodesmidae , fam. nov.This family is set up to include certain genera from the MississippiValley, Southeastern and Southwestern States formerly included in Xysto-desmidae, or in Chelode smidae from which it can be separated by the fol-lowing characteristics: mandibles with a tongue-like protuberance on theanterio-ventral margin of the pars basalts; unspined sternites, coxae, andprefemurs; male sternites setose, often with lobes; keels narrow to moder-ately wide; male gonopods consisting of a large basal division and a smalltelopodite which is simple, either setose or glabrous, and caudally directed;gonopodal opening of male with anterior margin always recurved medially(figure 2) and variously modified with lobes and setae, the lobes on the caudaland lateral margins. It resembles Xystodesmidae inhaving smooth tergiteswith the keels horizontal to somewhat depressed, their lateral marginsraised and not serrated.Type-genus: Eurymerodesmus Brolemann 1900. Other genera are KewaniusChamberlin 1938 and Paresmus Chamberlin 1942.Eurymerodesmus angularis, sp. nov.Figures 1-3This species resembles E. spectabilis Causey and E. bentonus Causeyin the shape of the lobes on the gonopodal opening of the male, but it canbe distinguished from both by differences in the shape of the telopodite ofthe gonopod and by the distribution of setae on it.Male holotype. Dorsum black-brown mottled with beige; mid-dorsalblack line; orange line around collum, around keels, and across tergites;pleurites dark; sternites cream; legs gray distally.Lateral margins of keels convex, but less so than in E. hispidipes(Wood). Caudal angles of keels 13 through 19 acute. Protuberance onpars basalis of mandibles relatively small, without pigment or ridges.Coxal joint of second legs with the usual two conical tubercles, the anteriorlarger. A pair of low, rounded, hirsute prominences on the metasternitebetween each pair of legs except first two and last two pairs. Metasternitebetween ninth legs 1 excavated medially as usual, the furrow narrow and thesetae no longer than those between the other legs (figure 1).These are the legs on the seventh segment directly behind the gonopods; theycorrespond in position to the ninth legs of the female.69Journal of the Arkansas Academy of Science, Vol. 4 [1951], Art. 12Published by Arkansas Academy of Science, 195170 ARKANSAS ACADEMY OF SCIENCEFIGURE 1. Eurymerodesmus angularis, caudal view of sternum between ninthlegs of male.FIGURE 2. Eurymerodesmus angularis, ventral view of gonopodal opening.FIGURE 3. Eurymerodesmus angularis, submedial view of left gonopod of male.Gonopodal opening bears posterio-laterally a pair of recurved lobes. Inlateral view the lobes appear triangular, shorter than the coxae of the ninthlegs, with the caudal surface pigmented and covered with setae and thecephalic surface without setae and dark pigment. In ventral view the lobesare seen to turn back medially; laterally they flare away from the marginand then turn in toward the bases of the ninth legs (figure 2). The marginsof the lobes are darkly pigmented and setose. A row of setae is across theposterior margin of the opening; the anterior margin was damaged, makingit impossible to determine whether there are setae there.Telopodite of gonopod (figure 3) relatively short, smoothly accuminate,and bent sharply distad. It bears three rows of setae; two rows are short,near the base, on opposite sides of the telopodite, and each is composed of12 or so setae almost as long as the telopodite; the third and longest rowis composed of shorter setae; the distal third of the telopodite is free ofsetae; at its base is a thick tuft of long setae.Length 23 mm, width 3.6 mm.A female collected with the male holotype and believed to belong tothis species agrees in general with the male but differs in the following:length 25 mm, width 3-8 mm; sternites glabrous.Locality. Arkansas, Prairie Co., De Vails Bluff. The male holotype andtwo females were collected by Mr. Le Roy Gray in April, 1950. The typespecimen will be deposited in the collection of the Academy of NaturalSciences of Philadelphia.70Journal of the Arkansas Academy of Science, Vol. 4 [1951], Art. 12http://scholarworks.uark.edu/jaas/vol4/iss1/12Of the numerous species of Eurymerodesmus , twelve are known to occurin Arkansas. Several females in my collection are believed to belong toadditional undescribed species. Systematic collecting in the state andadjoining areas would furnish interesting material for a study of speciationin this very plastic genus. A key to the Eurymerodesmidae occurring inArkansas willbe published in an early paper.7171Journal of the Arkansas Academy of Science, Vol. 4 [1951], Art. 12Published by Arkansas Academy of Science, 195172Journal of the Arkansas Academy of Science, Vol. 4 [1951], Art. 12http://scholarworks.uark.edu/jaas/vol4/iss1/12

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On Eurymerodesmidae, a New Family of Diplopoda (Strongylosomidea), and a New Arkansas Species of Eurymerodesmus

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