NASSID^E. 7 



Submenus HEBRA, H . and A . Adams. Whorls spinose, muricatcd or sharply 

 tubercular ; inner lip with the callus denned ; outer lip with a marginal 

 varix, when adult. 



Subgeuus HIMA, Leach. Spire elevated, whorls cancellated ; inner lip 

 with a rugose callus, callus defined ; outer lip with a marginal varix. 



Subgenus NIOTHA, H. and A. Adams. Shell cassidiform ; spire short, 

 whorls granulated or cancellated ; inner lip with the callus very large 

 and spreading ; outer lip crenate, not variced externally. 



Subgenus TRITIA, Risso. Spire elevated, whorls reticulated; inner lip 

 smooth, with the callus moderate; outer lip simple, not variced. -" 



Subgenus ILYANASSA, Stimpson. Shell dark olive brown, reticulated, 

 outer lip without varix, striate within, columella covered with a 

 spreading callus. Operculum with entire (not serrated) margin. 

 Animal having a broad foot, not bifurcated behind as in Nassa. Den- 

 tition, PI. 3, fig. 25. 



NERITULA, Plaucus. Shell ovate, depressed, axis distorted ; spire 

 flattened, oblique, whorls smooth ; aperture depressed ; columella 

 smooth ; inner lip callous, spread over the body whorl, outer lip reflected, 

 not denticulate or striated. Dentition, PI. 3, fig. 26. 



DESMOULEA, Gray. Shell ovate-globose, covered -with a downy 

 epidermis ; spire short, conical, apex papillary ; whorls depressed ; 

 aperture ovate ; inner lip thickened, with a ridge posteriorly ; outer 

 lip contracted, thickened externally, plicated internally. Dentition 

 unknown. 



Fossil Genera and Subgenera. 



Subgenus MOLOPOPHORUS, Gabb. (S. G. of Bullia). Short, robust, 

 spire moderately elevated, suture .bordered by a more or less distinct 

 carina. Surface longitudinally ribbed or striate. Aperture obtuse behind, 

 and very slightly notched; outer lip simple, inner lip very slightly in- 

 crusted, sinuous, anterior notch small, but distinctly defined. 

 B. STRIATA, Gabb. PI. 3, fig. 27. Cretaceous, California. 



Genus PTYCHOSALPINX, Gill. Shell ovate, buccinoid, whorls regu- 

 larly rounded and ventricose ; spire moderate (about as long as he 

 aperture), furnished with equal revolving linear ridges, siphonal canal 

 very short,, very obliquely twisted and concurrent with the siphonal 



* H. and A. Adams have also a subgenus Uzita, but its characters are 

 not different from those of Tritia, whilst its species are, many of them, 

 evidently better placed in other groups : a large number of them, for 

 instance, possess the marginal varix, the absence of which is one of the 

 characters of the group. Uzita can be advantageously dispensed with. 



