CRUCIBULUM. 



Genus CRUCIBULUM, Schumacher. 



Testa ovata nel orbiculari.1, nunc depressa nunc conoidea, 

 radiatim costata vel Urato-alriala, iiiterdum spinosa, 

 vertice stepmime snbcentrali. Appendix interna cya- 

 thifortnis, interdum lateraliter compressa. 



Shell ovate or orbicular, sometimes depressed, sometimes 

 conoid, radiately ribbed or ridge-striated, sometimes 

 spined, with the top mostly near the centre. Inter- 

 nal appendage cup-shaped, sometimes laterally com- 

 pressed. 



This genus, founded in 1817 by the eminent astronomer 

 and naturalist Schumacher, is retained for that section of 

 the Lamarckian Calyptnece in which the internal append- 

 age takes the form of a cup, which is sometimes free and 

 sometimes laterally compressed and attached. Concomi- 

 tant with this there is a marked generic difference in the 

 shell compared with the CalyptrrecB proper. In Crucibu- 

 lum there is no trace of the transparent thread-striated 

 tissue of Galyptrma. The shell is larger and much more 

 solidly developed, and generally dark-coloured. 



The Crucibula eminently belong to the New World. 

 One or two small species have been collected in the 

 Eastern Seas, bnt all those of mark are from California 

 and the western shores of Sonth and Central America. 



Species 1. (Fig. a, h, Mus. Cuming.) 



Crucibdlum tenue. Cruc. testa elevato-convexa, irre- 

 gidari, tenui, subdiaphand, creberrime striata, albidd, 

 interdiiM fusco-rubente paUide strigatd ; appendice in- 

 terna cyathiformi, subampld, eburned. 



The thin Ceucibuldm. Shell elevately convex, irre- 

 gular, thin, subdiaphauous, very closely striated, 

 whitish, sometimes faintly streaked with fuscous-red; 

 internal appendage cup-shaped, rather large, ivory- 

 white. 



Calyptrma leiiiiis, Broderip, Trans. Zool. Soc. vol. i. p. 199. 

 pi. 27. f. 9. 



Hab. Peru. 



A light shell, of very irregular growth, mostly painted 

 with rather faint, promiscuously divaricating, fuscous-red 

 streaks. 



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

 Ckdcibulum scutellatum. Cruc. ledd ovatd vel orbi- 



ctdari, suidepressa, radiatim fortiter ruyoso-costat a 

 costis striatis, interstitiis subobsolete imbricato-fines- 

 tratis, livido-cinered vel fused, varie marmorald,punc- 

 tis linearibus ntfo-fuscis interdum pictd, vertice late- 

 raliter subcompresso, uncinate ; appendice interna 

 cyathiforma, perampld, eburned, interdum fusco viar- 

 ginatd. 

 The shield-like Crucibulum. Shell ovate or orbi- 

 cular, rather depressed, radiately strongly wrinkle- 

 ribbed, ribs striated, interstices rather obsoletely im- 

 bricately latticed, livid-ash or brown, variously mot- 

 tled, sometimes painted with linear red-brown dots, 

 top laterally rather compressed, hooked; internal 

 appendage cup-shaped, very large, ivory-white, some- 

 times edged with brown. 

 Patella sculellaia. Gray in Wood Ind. Test. Supp. pi. 8. f. 4. 

 Calyptraa rugosa. Lesson. 



Calyptraa imbricata, Sowerby (not of Broderip). 

 Hab. Payta, Peru; Lesson. Punta, St. Elena, West Co- 

 lumbia; Cuming. 

 The typical state of the ribs of this species is, to be 

 rather spread and longitudinally striated, sprinkled with 

 linear i-ed-brown colouring, but these characters soon be- 

 come roughened or obsolete with age. 



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

 CucciBULUM TEIGONALE. Cruc. tcstd trigoTio-ovald, 

 crassd, profundi convexd, lesvigatd, versus marginem 

 pUcato-corrugatd, albidd, fusco-rubente varie strigatd, 

 vertice acute uncinato ; appendice ititernd cyathiformi, 

 perampld, eburned. 

 The tkiangulak Crucibulum. Shell triangularly ovate, 

 thick, deeply convex, smooth, plicately wrinkled to- 

 wards the margin, white, variously streaked with 

 fuscous-red, top sharply hooked ; internal appendage 

 cup-shaped, very large, ivory-white. 

 Calyptraa trigonalis, Adams and Eeeve, Moll. Voy. Sama- 



rang, p. 70. pi. 9. f. 7 a, b. 

 Ilab. China Seas. 



The principal distinguishing features of this species are 

 its triangular compression, which is alike in all specimens, 

 and not occasioned by any particular circumstances of at- 

 tachment, and plicately wrinkled margin, streaked with 

 fuscous-red as in C. teyme. 



December, 1858. 



