NASSARIA. 123 



rounded at the periphery ; umbilical region covered with a 

 large, flat callosity ; aperture transverse, rounded, greatly 

 produced and elongated, ending anteriorly in a slightly 

 canaliculated point ; inner lip smooth, callous, not emargi- 

 nate or truncate anteriorly ; outer lip thin, simple, not 

 margined or reflected. 



Ex. T. politum, A. Adams, pi. 12. fig. 9. 



This curious little genus very much resembles, at first 

 sight, Camitia of Gray, a genus of Trochidce, from which, 

 however, it is readily distinguished. Its true affinity is 

 with Neritula, from which it is known by the absence of 

 the notch at the fore part of the aperture, and by the very 

 peculiar elongation of the mouth. 



Species of Teinostoma. 

 anomalum, C. B. Adams. politum, A. Adaim. 



Genus NASSARIA, Link. 



Animal as in Phos, but without the caudal filament. 



Shell ovately fusiform ; spire acuminated, whorls longitu- 

 dinally ribbed and cancellated; aperture ending anteriorly 

 in a long recurved canal; inner lip thin, circumscribed, 

 transversely corrugately plicated; outer lip grooved in- 

 ternally. 



Syn. Hindsia, H. and A. Adams. 



Ex. N. alba. Martini^ pi. 13, fig. 1. Operculum, N. 

 acuminata. Reeve, fig. l,a, 1, ^. Shell, N. acuminata, 

 fig. 1, c. 



Nassaria resembles a Phos with an elongated, subre- 

 curved beak, and has been confounded with Tritonium; it, 



