cr> IT) i E> RARY OF THE U N IVLRSITY OF ILLINOIS 590-5 PI BIOLOGY Return this book on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for disciplinary action and may result in dismissal from the University. University of Illinois Library DEC LI61 O-1096 r l 34 20 FIELDIANA ZOOLOGY Published by CHICAGO NATURAL HISTORY MUSEUM Volume 34 JULY 24, 1953 No. 20 MOLLUSKS FROM ILHA GRANDE, RIO DE JANEIRO, BRAZIL *. I \irv i \ 6 " FRITZ HAAS CURATOR, DIVISION OF LOWER INVERTEBRATES Chicago Natural History Museum is indebted to Dr. Helmut Sick of Lapa, Rio de Janeiro, D.F., Brazil, for the collection of marine and non-marine shells here listed. Ilhe Grande, an island on the east coast of Brazil, almost under the Tropic of Capricorn, is an isolated and hence little-explored spot, so that the faunal list given here, although incomplete, is nevertheless of definite impor- tance; two species believed to be new to science are contained in the material collected by Dr. Sick during the years 1943 and 1944. MARINE MOLLUSKS Dentalium (Dentalium) texasianum no- Chama (Chama) congregata Conrad ense Henderson Chama (Echinochama) arcinella Linnaeus Dentalium (Antalis) disparile Orbigny Papyridea (Papyridea) spinosa Nucula (Nucula) crenulata A. Adams Meuschen Area (Area) deshayesi Hanley Laevicardium (Trachycardium) Area (Cucullaearca) Candida Gmelin muricatum Linnaeus Area (Argina) campechiensis pexata Say Laevicardium (Laevicardium) (new record for Rio de Janeiro) brasilianum Lamarck Area (Argina) campechiensis americana Venus (Lirophora) paphia Linnaeus Wood Venus (Antigona) rugatina Heilprin Area (Scapharca) auriculata Lamarck Venus (Chione) mazyckii Dall Area (Navicula) imbricata umbonata Dosinia (Dosinidia) concentrica Born Lamarck pu ar (Pitar) fulminatus Menke Mytilus (Chloromya) perna Linnaeus Piiar (Paradione) maculatus Linnaeus Crenella (Crenella) divancata Orbigny Gou i dia insularis Dall and Simpson (new record) ( new recor d) Modiolu* (Modiolus)tuli P a Linnaeus Gouldia cerina c< B> Adams vo Ostrea (Ostrea) puelchana Orbigny Mactra (Mactrotoma) petiti Orbigny Pecten (Nodipecten) nodosus Linnaeus Mactra (Mactrotoma) fragilis Chemnitz Pecten (Euvola) ziczac Linnaeus Sangwnolana (Sanguinolana) rosea Spondylus echinatus Martyn _ " rne ' 1 " Phacoides (Bellucina) amiantus Dall Tagelus (Tagelus) gibbus Spengler Phacoides (Lucinisca) muncatus Speng- Stngilla (Stngilla) carnana Linnaeus ler (new record) Solen (Solen) rostriformis Dunker Divaricella (Divaricella) quadrisukala Saxicava (Saxicava) solida Sowerby Orbigny Corbula (Caryocorbula) cubaniana Divaricella (Divaricella) denlata Wood Orbigny No. 718 203 204 FIELDIANA: ZOOLOGY, VOLUME 34 Corbula (Caryocorbula) caribaea Orbigny Corbula (Corbula) nasuta Sowerby (new record) Bullaria (Bullaria) striata Bruguiere Acteocina candei Orbigny Cylichna sp. (broken; new species?) Siphonaria lepida Gould Lucapina (Lucapina) meta Ihering Lucapina (Lucapina) adspersa Philippi Diodora patagonica Orbigny Fissurella (Cremides) rosea Gmelin Acmaea (Collisella) subrugosa Orbigny Tegula (Chlorostoma) viridula viridula Gmelin Astraea (Astralium) brevispina Lamarck Tricolia (Tricolia) pygmaea Philippi Littorinopsis (Littorinopsis) columellaris columellaris Orbigny Littorinopsis (Littorinopsis) ziczac Gmelin Rissoina (Schwartziella) woodwardi Carpenter Caecum (Fartulum) vitreum Carpenter (new record) Alaba tervaricosa C. B. Adams Thericium atratum Born Alabina cerithioides Dall Diostoma varium Pfeiffer Melanella (Melanella) unifasciata Forbes Melanella (Melanella) subcarinata Orbigny (new record) Melanella (Balcis) glabra Jeffreys (new record) Turbonilla (Turbonilla?) pusilla C. B. Adams Crepidula (Crepidula) aculeata Gmelin Strombus (Strombella) pugilis nicaraguensis Fluck Natica (Natica) canrena Linnaeus Natica (Tectonatica) micra sp. nov. (description, p. 206) Sinum (Sinum) perspectivum Say Polinices (Naticina) lacteus Guilding Cabestana (Monoplex) costata Born Hexaplex (Phyllonotus) chrysostomus Sowerby Thais (Stramonita) haemastoma Linnaeus Cantharus (Pollia) caribaeus Orbigny Ithycythara hyperlepta sp. nov. (description, p. 207) Anachis (Anachis) terpsichore Sowerby Anachis (Zafra) obesa C. B. Adams Leucozonia (Leucozonia) cingulifera Lamarck Pisania (Prodotia) janeirensis Philippi Fusus (Fusus) marmoratus Philippi Olivella (Olivella) floralia Duclos Olivella (Olivella) jaspidea Gmelin Some of the species contained in the preceding list were not taken on the beach or in the littoral water; Dr. Sick extracted them from the intestines of various animals, from which some of them were even obtained alive. The collections listed according to such sources follow: INTESTINE OF SEA CUCUMBER Small opisthpbranchiate gastropod, genus Cylichna, broken and unclassifiable Melanella (Melanella) subcarinata Orbigny Alaba tervaricosa C. B. Adams Diostoma varium Pfeiffer Turbonilla (Turbonilla) pusilla C. B. Adams Modiolus (Modiolus) tulipa Linnaeus (very young) Phacoides (Lucinisca) muricatus Spengler Gouldia cerina C. B. Adams Venus (Lirophora) paphia Linnaeus INTESTINE OF STARFISH Mytilus (Chloromya) perna Linnaeus (very young) Corbula (Caryocorbula) caribaea Orbigny Diodora patagonica Orbigny (very young) Tricolia (Tricolia) pygmaea Philippi Caecum (Fartulum) vitreum Carpenter Thericium atratum Born (young) Anachis (Anachis) terpsichore Sowerby Olivella (Olivella) floralia Duclos HAAS: MOLLUSKS FROM BRAZIL 205 | STOMACH OF SEA SLUG 1 Modiolus (Modiolus) tulipa Linnaeus Diostoma varium Pfeiffer (young) Tricolia (Tricolia) pygmaea Philippi Cylichna sp. (broken) LAND AND FRESH-WATER MOLLUSKS Oxychilus (Oxychilus fruhstorferi O. Opeas (Opeas) gracile Hutton Boettger (classification doubtful) Opeas (Opeas) micrum Orbigny Solaropsis (Solaropsis) braziliana Opeas (Opeas) beckianum Pfeiffer Deshayes Opeas (Opeas) goodalli Miller Endodonta janeirensis Thiele Subulina (Subulina) octona Bruguiere Amphidoxa (Stephanoda) pleurophora Leptinaria (Leptinaria) lamellata Moricand Potiez and Michaud Habrocpnus(Pseudoguppya) semen-hm Caecilioides (Geostilbia) gundlachi Moricand Pfeiffer S l2Sri2Sd (Simpul p8is} ru f ovirens Obeliscus (Ischnocion) sp. (see Simpulopsis (Simpulopsis) sulculosa comment below) FeVussac Succinea (Hydrophyga?) mendionahs Gastrocopta (Gaslrocopta) servilis Orbigny (j ou ld Burnupia (Amsancylus) obhquus Happia (Happia) vitrina J. A. Wagner Broderip and Sowerby Streptaxis (Scolodonta) spirorbis Helicina (Oxyrhombus) inaequistriata Deshayes Pilsbry E Zaplagius auris-leporis Bruguiere Pisidium globulus Clessin COMMENTS AND DESCRIPTIONS OF NEW SPECIES MENTIONED ABOVE The following species, both marine and non-marine, listed above had never before been recorded from the region of Rio de Janeiro: Area (Argina) campechiensis pexata Ervilea rostratula Rehder Say Corbula (Corbula) nasuta Sowerby Crenella (Crenella) divaricata Orbigny Caecum (Fartulum) vitreum Carpenter Phacoides (Lucinisca) muricatus Melanella (Melanella) subcarinata Spengler Orbigny Gouldia insularis Dall and Simpson Melanella (Balds) glabra Jeffreys Tricolia (Tricolia) pygmaea Philippi was described from an un- known locality, and our specimen of this species from Ilha Grande may be the first supplied with exact data. Obeliscus (Ischnocion) sp. This find is entitled to a somewhat more explicit comment. The subgenus Ischnocion was erected by Pilsbry in 1907 for what he thought was an aberrant Leptinaria; Thiele, however (1931, p. 555), grouped Ischnocion with the subgenera of Obeliscus, and I follow him in this arrangement. The only species of Ischnocion (triptyx Pilsbry 1907, from Colombia) was apparently never recorded again, until (1951, p. 512) I was able to list it from a collection gathered in the Peruvian Andes. Thus it seems that the 1 Apparently, from description submitted by Dr. Sick, Aplysia brasiliana Rang. 206 FIELDIANA: ZOOLOGY, VOLUME 34 species Obeliscus (Ischnociori) triptyx Pilsbry is an Andean form; in this connection it is of interest that another species of the subgenus Ischnocion is recorded here from eastern Brazil. Unfortunately the unique specimen at hand has the aperture broken, though the colu- FIG. 41. Natica (Tectonatica) micro, sp. nov. C.N.H.M. no. 43961, type. Above, front and back views of shell; below, outer and inner views of operculum. All about X 6. mellar region with its characteristic features is intact. There are seven whorls and the height of the shell is only 4.5 mm.; probably the specimen is not yet adult. I therefore refrain from naming and describing it, though there cannot be a doubt that it constitutes an undescribed species, and I confine myself to reporting a member of the subgenus Ischnocion from Ilha Grande, i.e., from the State of Rio de Janeiro in eastern Brazil. Natica (Tectonatica) micra sp. nov. Figure 41. Type. Chicago Natural History Museum no. 43961, from Ilha Grande, State of Rio de Janeiro, Brazil. Collected, 1944, by Dr. Helmut Sick. HAAS: MOLLUSKS FROM BRAZIL 207 Diagnosis. A species of the subgenus Tectonatica (genus Natica) characterized by its extreme smallness, by the roundish conic-ovate shell without a prominent apex, and by the light chestnut color of the conchinic layer. Comparisons. There are none among the consubgeners, and even the congeners, to which this novelty might be compared as far as the shape and the coloration of the shell are concerned, for no other Natica offers a shape with such a broad, not prominent, apex, or a shell coloration comparable to that of micra. The aperture and the umbilical callus are comparable to those existing in Natica (Natica) sagraiana Orbigny-. 1 Description of type. Shell rather solid, smooth, globular conic- ovate, with flat apex not prominent above the second whorl. Whorls 3^4, of very rapid growth, the very swollen last one practically as high as the entire shell; suture shallow, appressed, the last whorl somewhat flattened or even concave near it; aperture somewhat more than half the height of the shell, pear-shaped, with thickened, white margins, pointed and somewhat protracted above, broadened at the columellar margin into a heavy callus that enters and almost closes the umbilicus, leaving merely a narrow chink open; this chink continuous, below, with a furrow running across and downward to the basal columellar margin. Conchinic layer without a pattern, of a light chestnut color. Operculum thin, somewhat curved, of a light brown color. Measurements of type. Height 4.4 mm., width 3.4 mm., height of aperture 2.5 mm., width of aperture 1.9 mm. Paratypes. Chicago Natural History Museum no. 43962, with the same data as the type; four specimens identical with, but some- what smaller than the type. Ithycythara hyperlepta sp. nov. Figure 42. Type. Chicago Natural History Museum no. 43963, from Ilha Grande, Rio de Janeiro, Brazil. Collected, 1943, by Dr. Helmut Sick. Diagnosis. A typical species of the genus Ithycythara, charac- terized by its extreme slenderness and by the hexagonal cross section of the shell. Comparisons. "Mangelia" hexagonalis Reeve from the Indo- Pacific Ocean resembles this novelty in having six longitudinal, con- 1 Natica pusilla Say, from the southeastern United States, is of about the same size as this new species, but it is rather distinct. 208 FIELDIANA: ZOOLOGY, VOLUME 34 tinuous ribs, but it is considerably stouter. Ithycythara pentagonalis Gray from the West Indies is very much like the new hyperlepta as far as the general appearance is concerned, but it has only five longi- tudinal sets of ribs. Description of type. Shell elongate, very slender, subsolid, whit- ish brown with a waxy gloss. Whorls 10, the earlier ones with FIG. 42. Ithycythara hyperlepta sp. nov. C.N.H.M. no. 43963, type. Front and back views of shell. All about X 6. straight outlines, the later ones becoming gradually somewhat con- vex. Six sets of equally spaced, prominent, and continuous ribs adorn the otherwise plain surface of the shell on which retractive growth-lines are visible, causing the slightly sigmoid curvation of the ribs. The surface between the ribs is flat or even minutely concave, so that, in a cross section, the shell has the appearance of a hexagon with concave sides. The aperture is about one-fourth as high as the entire shell, very narrow with almost parallel sides, ending in a point above and in a short, truncated canal below; lip incision short, near the suture. Measurements of type. Height 7.9 mm., width 1.8 mm., height of aperture 2.0 mm., width of aperture 1.2 mm. HAAS: MOLLUSKS FROM BRAZIL 209 REFERENCES HAAS, FRITZ 1951. Remarks on and descriptions of South American non-marine shells. Fieldiana, Zoology, 31: 503-545, figs. 97-126. PILSBRY, H. A. 1907. Manual of Conchology. (2), 18: Achatinidae, Stenogyrinae and Coeli- axinae. 357 pp., 51 pis. THIELB, J. 1929-31. Handbuch der systematischen Weichtierkunde. 1, 778 pp., 782 figs. UNIVERSITY OF ILLINOIS-URBANA