398 RALPH TATE. 
Genus Bathytoma, Harris and Burrows, 1891. 
(Dolichotoma, Bellardi, 1875, non Hope 1839). 
Columella twisted ; sinus removed from the suture, enbryo 
conoidal. 
The species of Genotia described in the first supplement of a 
Census, &c., belong to Bathytoma, this position was antecedentally 
assigned to them, as list names.’ In my former paper, Genotia 
was used in the belief that Dolichotoma might be synonymous, 
that view being based on the similitude of G. atractoides, Watson, 
with certain of our species of Bathytoma ; the reconciliation of 
these discrepancies is made good by Boettger, who affirms that 
the living species described and figured in the “ Challenger 
Gasteropoda” belongs to Dolichotoma. Genotia is classed by 
Cossmann in Oonide near to Conorbis. 
The following are diagnostically known :—Genotia fontinalis, 
decomposita, Pritchardi, and angustifrons, Tate; Plewrotoma 
paracantha, Tenison-Woods. Pleurotoma rhomboidalis, Tenison- 
Woods, has no specific characters, it represents the tip of 4 
Bathytoma. 
Genus Asthenotoma, Harris and Burrows, 1897. 
Oligotoma, Bellardi, 1875 (non Westwood, 1836). 
Columella with one plication, canal short, sinus large. 
Examples, Pleurotoma consutilis, Ten.-Woods, and Asthenotom@ 
Tater, Cossmann.? 
Subfamily MANnGILIniIn&. 
No operculum ; sinus at the suture, embryo papillary. 
Genus Clathwrella. 
Outer ips varicose, internally plicate ; canal short, columella 
wrinkled. Examples, Mangilia bidens, Ten. acy and C. obdith 
Harris 
. 
1 Trans. Roy. Soc, S. Aust., Vol. xvi, p. 221. 
2 Essais, Part II., p. 173, t. 6, fig. 29, 1896. 
