160 PLEUROTOMID^E. 



It is retained as a genus to prevent the duplication of specific 

 names. 



Ditoma and Atoma, Bellardi, are groups found in the Italian 

 tertiary which may be here referred. 



Genus DAPHNELLA, Hinds, 1844. 



Shell thin, fragile, oval-fusiform ; whorls convex ; body-whorl 

 elongated, surface finely cancellated ; aperture oval ; lip simple, 

 not varicose, arcuated ; canal very short. Warm. Seas. 



Small and elegant shells, of slight texture, distinguished by 

 their elongated body-whorl, tenuity and sculpture. 



The following may be considered sections of Daphnella : 



Section RAPHITOMA, Bellardi, 1847. Shell small, fusiform, or 

 turriculated, with longitudinal sculpture; lip sinuous behind, 

 but without well-defined sinus. There are a number of tertiary 

 species. 



Section HOMOTOMA, Bellardi, 1875. Whorls canaliculated at 

 the suture. Tertiary only. 



Section TERES, Bucq., Dautz. and Dollf., 1882. Shell fusiform ; 

 spire long ; sinus profound ; columella straight, obliquety trun- 

 cate at the base. 



Section BELLARDIELLA, Fischer, 1883 (Bellardia, Bucq., Dautz. 

 and Dollf., 1882, non Mayer, 1870). Form lanceolate, similar to 

 that of the true Pleurotomas ; sinus sutural ; canal rather long. 



Section ZAFRA, A. Adams, 1872. Shell acuminately oval, 

 tumid in the middle ; whorls longitudinally plicate, the last 

 constricted at the base ; aperture linear ; inner lip effuse, its 

 margin free; outer lip acute, subsinuous behind, subinflected in 

 the middle. 



Seminella, Pease, which has by some been considered identical 

 with Zafra, appears to me to be Columbelloid, and I have so 

 treated it in vol. v of this work. 



Section THESBIA, Jeffreys, 1867. Shell thin, rather smooth, 

 somewhat tumid, with a short spire and irregularly contorted 

 apex ; aperture slightly expanded, the outer lip thin, with distinct 

 sinus ; canal short ; columella simple. 



Section TARANIS, Jeffreys, 1870. Shell minute, cancellated, 

 whorls angulated ; slightly exserted at base ; aperture pyriform ; 

 outer lip thin, simple ; sinus obsolete ; canal short. 



