212 CLASS III. GASTEROPODA. ORDER VII. PECTINIBRANCHIATA. 
Pl. CCLIV. Fig. 1 to 3. 
ONISCIA CANCELLATA, Sowerby, Genera of Shells, No. 24. 
Cassidaria cancellata, Kiener. 
Pl. CCLIV. Fig. 4. 
OnisciA oniscus, Sowerby, Genera of Shells, No. 24. Chemnitz, Conch., 
vol. xi. pl. 195 A. f. 1872 and 1873. 
Strombus oniscus, Linnzeus. 
Cassis verruculatus, Martini. 
Cassidaria oniscus, Lamarck. 
Pl. CCLIV. Fig. 5. (fossil.) 
Oniscia cirHarA, Sowerby, Genera of Shells, No. 24. 
Buccinum cithara, Brocchi, Conchologia Fossile Subappenina, pl. 5. f. 5. 
CASSIS, Klein. 
Testa ovata, vel trigona, anfractu ultimo inflato, varicibus interdum re- 
moté armata, n canalem brevem, subito reflexum, desinens ; apertura 
longitudinali ; labro columellari sepé rugoso, aut granuloso. 
The shells of the Cassides appear to have been known by the common 
appellation of ‘‘ Helmets” from the time of Bonanni; Klein was, how- 
ever, the first author who associated them in the system with any de- 
gree of regularity. His arrangement was, nevertheless, disregarded by 
Linneus: the extreme caution with which the operations of that great 
the rich scarlet appearance of the columellar lip is moreover remarkable ; and as this portion 
of the shell constitutes its chief generic character, may not so decided a variation of it be alone 
considered of sufficient specific importance? The specimen from which our drawing is taken 
belongs to J. Dennison, Esq., a gentleman well known in the conchological world as an assi- 
duous collector of shells; we have been informed that there is another specimen in existence, 
but in very bad condition. 
