C HONDRO POM A. 



Plate I. 



Genus CHONDROrOMxV, Pfiiffer. 



Testa ohloiKjo-lvrrita, rariits globoso-turbinata , plerinnque 

 dense filo-lirata vel reticulata, ad siituras creniilala ; 

 upertura parviiiscnla, ovniis, labro nunc simplici vel 

 expanso, nunc fimbrialo. Operculum ovale, subcarti- 

 lagineum, plauum, aufractibus paucis, rnpide accres- 

 centibus, nucleo pleruiuqiie valde esceulrico. 



Shell oblong-tiirreted, rarely globosely turbinated, gene- 

 rally densely thread-ridged or reticulated, and crenu- 

 lated at the sutures ; aperture rather small, oval, with 

 the li|) sometimes simple or expanded, sometimes 

 fimbriated. Operculum oval, somewhat cartilaginous, 

 fiat, whorls few, increasing rapidly, nucleus mostly 

 far removed from the centre. 



This genus, in which I include Chtula of Gray, and of 

 Pfeiffer's monograph, is characterized by the operculum 

 being of a flat cartilaginous substance, of a few rapidly 

 incrcashig whorls, with the nucleus removed from the 

 centre. It comprises about ninety species, all inhabiting 

 the islands of the West Indies and the adjacent lands of 

 Venezuela, Guatemala, and Florida ; but the Continental 

 species are comparatively few in number. The shells are, 

 for the most part, characterized by a remarkable similarity 

 of form and sculpture, oblong-turreted, densely crowded 

 with raised thread-like striffi or ridges, vi'hich in some spe- 

 cies I'un longitudinally only, in others both longitudinally 

 and transversely, producing a more or less elaborately woven 

 reticulation. The aperture of the shell is generally smalL 

 circularly ovate, and findjriated, and when the frill is au- 

 ricled at the upper part, which is not unfrequently the 

 case, the auricles are deposited within the suture, as the 

 whorl advances in growth, iu' tooth-like creuules. In a 

 few species the longitudinal striae assume the form of 

 erect laraellaj or membranaceous threads, and they are 

 often rendered scabrous by decussating incised striae. The 

 colouring of the shells is mostly fulvous, variously banded, 

 streaked, or freckled with reddish brown. 



Species 1. (Fig. «, b, c, Mus. Cumiug.) 



Chondropoma MAGNincA. Ckond. testa ovato-conicd, 

 subcylindraced, plus minus mnbilicatd, diapJiano-albd, 

 strit/is vittisque rufesceute-fuscis cingulatd, aufractibus 

 tumido-convexis, dense lomjitudinaliter jilo-liratis, liris 



diapJianis ; aperturd ovatd, labro late Jimbrialo-rejlexo, 

 fusco lineari-radiato. 



The MAGNIFICENT Chondropoma. Shell ovately conical, 

 subcylindrical, more or less umbilicated, diaphanous 

 white, encircled with red-brown streaks and fillets, 

 whorls tumidly convex, densely longitudinally thread- 

 ridged, ridges diaphanous ; aperture ovate, lip broadly 

 fimbriately reflected, lineally rayed with brown. 



Cyclostoma magnificum, Pfeift'er, Pro. Zool. Soc. 1S32, 

 p. 1-13. pi. 1.3. f. 3. 

 Chondropoma maynificum, PfeifiFer. 

 Chondropoma Gutierrezi, Poey. 



Hub. Island of Haiti, West Indies ; Salle. 



Of a delicate diaphanous white, finely stringed through- 

 out with thread-like ridges of similarly diaphanous sub- 

 stance, the whorls being encircled with red-brown fillets 

 and bands of streaks, conspicuously rayed in the apertm-e. 



Species 3. (Fig. a, b, Mus. Cuming.) 



Chondropoma Weinlandi. Chond. testa vix umbili- 

 catd, elongato-cylindraced, albidd vel rufescente-au- 

 rantid, castaneo-fusco varie strigatd, fasciatd, vet 

 piiuctatd, aufractibus modice convexis, creberrime pli- 

 cato-slrlatis ; aperturd oblique ovatd, parvd, siiperni 

 carinatd, subsotutd, labro simplici, continue. 



Weinland's Chondropoma. Shell scarcely umbili- 

 cated, elongately cylindrical, white or reddish orange, 

 variously streaked, banded or dotted with chestnut- 

 brown, whorls moderately convex, very closely pli- 

 cately striated ; aperture obliquely ovate, small, 

 keeled at the upper part, a little detached, lip 

 simple, continuous. 



Pfeiffer, Malak. Blat. 1863. 



Chondropoma semilabre, Pfeiflfer (not Cyclostoma semi- 

 labre, Lamarck). 



Hab. Island of Haiti, West Indies ; Salle. 



Extremely variable in painting, but constant in foi'm ; 

 a somewhat elongately cylindrical form, with a small semi- 

 detached aperture. 



Species 3. (Mus. Cuming.) 



Chondropoma egregium. Chond. testa coarclate umbi- 

 licatd, ovato-conicd, sericeo-aurantid, rufescente-fusco 



January, 1863. 



