276 ATYS. 



sometimes closely appressed and sometimes loose with a chink be- 

 hind it, but there is no anterior pit ; the shell is more slender for- 

 ward than behind, the bevelling is more marked in some specimens 

 than in others a fragment from off Havana, if tonspecific, as seems 

 likely, indicates that it reaches a much larger size than the -de- 

 scribed specimens. Lon. of shell and aperture, 6'5. Max. lat. of 

 shell, 3'4, of aperture 1*75 mill. ; lat. of aperture 0'5 mill. {Dull). 



Off Bahia Honda, Cuba, 220 fms. ; Near Santa Cruz, 38 fms. 

 Atys f sandersoni Dall., Bull. M. C. Z. ix, p. 99, 1881 ; Blake 

 Gastr. p. 54, pi. 17, f. 7. 



A. CASTA Carpenter. Unfigured. 



Shell elongated, thin, subdiaphanous, whitish ; a little more swol- 

 len anteriorly ; spire concealed, lacunate, in adult shells hardly 

 umbilicated ; columella a little intorted, effuse ; umbilicus small ; 

 lip produced posteriorly, obtusely angulated ; entire surface subtly 

 spirally striatulate. Alt. .4, diam. "18 inch (Cpr.). 



Cape St. Lucas. 



? Attjs casta Cpr., Ann. Mag. N. H. (3), xiii, p. 314, 1864 ; Moll 

 AVesternN. A. p. 104, 212. 



On the confines of the genus related to Cylichna (Cpr.). 



Subgenus Dinia H. & A. Ads., 1854. 



A. DENTiFERA A. Adams. PI. 27, fig. 81. 



Shell ovoid, posteriorly subtruncated, anteriorly produced, horny, 

 pellucid, longitudinally sulcated ; outer lip simple, acute ; inner lip 

 anteriorly strongly truncated, ending in a dentiform plate (Ad.). 



Lord Hood's Island (Cuming); (S'ue^; (Cooke) ; Mauritius (^sl&rt.)', 

 Levuka, Fiji (Challenger). 



Bulla (Atys) dentifera Ad., Thes. p. 588, pi. 125, f. 124.— .4. den- 

 iifera Sowk., C. Icon. t. 2, f. 13.— Cooke, Ann. Mag. N. H. (5), 

 xvii, p. 133. — Martens, Meeres-fauna Maurit. p. 303. — Atys (Di- 

 nia) dentifera Ads., Genera, ii, p. 21. — "NVatson, Chall. Rep. p. 

 641. 



A. MONODONTA A. Adams. PL 28, fig. 17. 



Shell subcylindrical, posteriorly subtruncated, anteriorly pro- 

 duced, solid, opaque, longitudinally grooved ; outer lip indexed in 

 the middle ; inner lip strongly truncated anteriorly, and ending in 



a dentiform plate (Ad.). 



Shores of Borneo (Cuming). 



