p. 297-300, [3] leaves of plates : ill. ; 24 cm.Includes bibliographical references

Greene, George K.

Whitfield, Robert Parr, 1828-1910.

American Museum of Natural History Scientific Publications

56-34 ( 114:77.2).Article XVII.-DESCRIPTIONS OF NEW FOSSIL SPONGESFROM THE HAMILTON GROUP OF INDIANA.By R. P. WHITFIELD.PLATES IX-XI.Among the numerous fossils purchased from Mr. G. K. Green, ofNew Albany, Indiana, there is a series of fossil sponges from theHamilton Group, at and near Speed's quarry, in the vicinity ofCharlestown, Clark Co., Indiana, that appears not to have beennoticed by any one up to the present time, as I can find no genericor specific names under which the forms can be readily or satis-factorily placed. They comprise three distinct types, or genericgroups; although associated together and in the same state of preser-vation, they are probably fundamentally distinct from each other.All are so thoroughly silicified that none of the microscopical featuresof their structure can be obtained; in fact, they are often completelyagatized.One of the forms presents a somewhat similar appearance to thatwhich is often seen on a species of Favosite that has been deformedby severe compression in a soft matrix, retaining the semblance,however, of a group of tubes or cells, but without distinctive specificcharacters. This form -rather closely resembles the figures of Som-phospongia, as given by I. W. Beede, in Vol. VI of the Kansas Geol.Report for I900, plate ii, figs. I-5. It also appears to be fully asdiverse in form as that one.A second form among them is usually conical, often highly so0though sometimes almost flat; the upper surface being finely pittedand sometimes indistinctly striate radially, especially on the underside around the edge and near the base of the cone. This form isquite generally attached to the upper valve of a species of Discina-like shell, resembling Roemerella grandis Vanuxem but usually moreelevated. The structure of this sponge (if it be a sponge) is verycompact, and the substance is so thoroughly replaced by silica as toentirely obliterate all other internal features. If turned upside downit might readily be mistaken both in form and surface marking forPalaomanon cratera Roemer, from the Silurian strata of Perry County,Tennessee.The third form differs again entirely in its general structure and[297]298 Bulletin American Museum of Natural History. [Vol. XXI,surface features. It is as multiform in shape as the first mentioned,being irregularly spherical, conical, or depressed convex. One speciesis dactyloid. The surfaces of all, however, present the same char-acteristic, namely, that of looking as if one had gathered togetherthe castings of an earthworm from soft mold and pressed them intoshape without destroying entirely their vermiform appearance.Hence the name Vermispongia.Vermispongia, gen. nov.Bodies more or less spherical in form, conical, compressed spheroidal, oroccasionally flattened. Composed of partially isolated particles, which resem-ble the castings of earthworms closely pressed together, forming irregularlyshaped masses without entirely destroying their cylindrical form. The indi-vidual masses bear evidence of attachment to foreign bodies.Microscopical features of the skeleton not obtainable. Geological horizonHamilton Group.Vermispongia hamiltonensis, sp. nov.PLATE XI, FIGS. I-5.Species extremely various in form, generally of a more or less compressedspheroidal shape, and quite frequently showing evidence of attachment to someforeign body, generally the shell of a brachiopod. The outer surface presentsthe appearance of being composed of loose, string-like material closely compressedinto rounded masses, as if a group of the castings of earthworms had beenpresse(d into this shape without entirely destroying the cylindrical form.Many of the specimens in the collection show on their under surface remainsof the shells of Strophaodonta, Chonetes, and one of Roemerella grandis.Vermispongia dactyliformis, sp. nov.PLATE XI, FIG. 6.A single individual of what would appear to be a distinct specific form occursin the collection. It is two and a half inches long (iol cm.) by seven-eighthsof an inch wide (IA mm.) in its flattened condition. The surface presentsalmost the same appearance as those of the last species, but has been wornslightly and in this condition looks extremely like the figures of Streptosolen,given by Mr. E. 0. Ulrich in Vol. VIII of the Illinois Geol. Surv. Reports,plate iv, figs. 4 and 4a, but I have concluded to place it under the above namedgenus in preference. The geological horizon of the specimen is established bythe fact that it bears the markings of Strophaodonta perplana and Choneteslspida, and that attached to it is a small cheek plate of a Pradus.The second form mentioned is so closely similar in its externalfeatures to one figured by Mr. E. 0. Ulrich in Vol. VIII of the IllinoisEXPLANATION OF PLATE IX.SOMPHOSPONGIA FAVOSITIFORMIS, Sp. nov.FIGS. 1-5.-Specimens of various sizes illustrating the general form of thespecies in its younger stages.FIG. 6.-Lateral view of a large conical form of the usual character.FIG. 7.-View of a section through the center of specimen shown in Fig. 6.FIGS. 8 and 9.-Two views of a larger specimen showing the radiating characterof the side and the irregular cell-like form of the surface.(All figures are from photographs, nat. size.)Bulletin A. M. N. H..4g"St^+X.FOSSIL SPONGES.Vol. XXI., Plate IX.EXPLANATION OF PLATE X.HINDIA INDIANENSIS, sp. nov.FIGS. i and 2.-Lateral and basal views of a small, quite perfect specimen,showing the prevailing form and on Fig. 2 the markings of Roe-merella grandis Vanuxem.FIG. 3.-Side view of a medium-sized individual of the ordinary form, showingthe general structure of the surface.FIG. 4.-View of a specimen overgrown with the Hamilton bryozoan Palcescharareticulata Hall.FIG. 5.-View of the base of a large specimen, somewhat weathered and worn,showing the radiating structure.FIG. 6.-View of a section of a specimen of the ordinary form, illustrating thehighly silicified character of the entire group, chalcedonized,which has entirely destroyed all the features of the sponge, exceptform.(All figures are from photographs, nat. size.)Bulletin A. M. N. H.'.' .;A#. .I.3 _I,FOSSIL SPONGES.Vol. XXI., Plate X.EXPLANATION OF PLATE XI.VERMISPONGIA HAMILTONENSIS, sp. noV.FIGS. x and 2.-Views of a solid specimen, Fig. t, showing a natural verticalsection, and Fig. 2, the natural outer surface.FIG. 3.-Top view of a flattened individual.FIG. 4.-Natural surface of a small ovate specimen.FIG. S.-The under surface of a specimen, showing its starting-point to havebeen on a specimen of Strophkodonta perplana Conrad.VERMISPONGIA DACTYLIFORMIS, sp. nov.FIG. 6.-Side view of the only specimen of the species known.(All figures are from photographs, nat. size.)Vol. XXI., Plate Xl.t'.'IS '1ILLUSTRATIONS OF VERMISPONGIA.Bulletin A. M. N. H.Geol. Surv., plate vii, fig. 3, under the name Actinostroma trentonensis,that, were it not for the difference in their geological position, I shouldbe strongly inclined to refer our specimens to that species, but therecan be no question as to their Devonian origin, as I find, besides theDiscina-like shell above referred to, several well authenticated Ham-ilton Group fossils attached to the bases of the specimens, showingthat the sponges grew upon them. One specimen of this form I alsofind nearly half covered by a growth of Palwschara reticulata, abryozoan common in the Hamilton Group of New York, whichthrows up solid stems from the spreading base.The resemblance of this species to an over-silicified form of Stroma-topora or Actinostroma is certainly very great, but I am much moreinclined to think it pertains to the genus Hindia Duncan, as repre-sented in the Astylospongia inornata of Hall. On a large overgrownspecimen, badly weathered, one can readily see indistinctly a re-semblance to the peculiar structure often observed on that species.I have therefore concluded to refer this species to the genus HindiaDuncan, with the following description.Hindia indianensis, sp. nov.PLATE X, FIGS. i-6.Body conical, more or less elevated, often compressed and flattened. Quitegenerally showing an attachment in early stages of growth to a Discinoid shell(Roemerella grandis Vanuxem) or other foreign substance. Base always (?)concave, flattened at the margins and often rounded on the outer edge. Muchweathered specimens show an incipient radial striation on the flattened borderof the base, and a finely punctate structure on the upper surface, but no definiteorder of the punctation can be discovered. Size varying from less than oneinch to fully three inches in diameter. Height very variable.Geological formation and locality. - In the Hamilton Group at and aboutSpeed's quarry, near Charlestown, Indiana.The Hamilton Group fossils recognized on the bases or attachedto specimens of this species are the following: Strophwodonta demissaConrad, Productella shumardana, Chonetes yandellana, Tropodoleptuscarinatus. Upon those associated with it I find Strophwodonta per-plana, Craniella hcamiltoniac, Spirifer segmenta, and Phacops ranaGreen.The first form mentioned at the beginning of this article, the onesomewhat resembling a crushed or deformed member of the Favo-sitidae, I have concluded to place under the same generic head as the4Whitfield, Nezv Fossil Sponges.I 905.] 299;300 Bulletin American Museum of Natural History. [Vol. XXI.one mentioned as being illustrated in the Kansas Geological Report,namely, Somphospongia, and under the following name:Somphospongia favositiformis, sp. nov.PLATE IX, FIGS. 1-9.Sponge body flattened, spherical, globular, or conical with a concave base,or, in some cases, almost discoid; the structure being made up apparently of amass of compressed and laterally crushed irregular tubes, while these appear tobe made up or increased by lateral expansions from the edges of the alreadyformed tubes. The natural surfaces of the separate bodies are therefore rough,either knobby, tuberculose, or presenting the appearance of cells like those ofFavosite tubes, crushed. or distorted. The microscopic structure of the frame-work is not obtainable owing to the condition of preservation. A single speci-men very highly silicified shows the arrangement of the tubes, or breathingpores, in a decidedly radiant manner, but no evidence of spicular arrangementof the skeleton can be gotten from it. The specimen is figured on Plate IX,Figs. 8 and 9.This species is quite frequently shown to have started on Stro-phcodonta perplacna Conrad, eight specimens out of fourteen presentin the collection having started growth on that species of brachiopod,while one is attached to a valve of S. concava (?)., one to Roemerella, oneto Spirifer segmenta, one to Craniella hamiltonice, and one to whatmay have been a small Atrya histrix Hall.

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