MOHNIA, STPHONALIA. 133 



S. DALLI, Friele. PL 87, fig. 625. 



S. UNDULATUS, Friele. PI. 87, fig. 626. 



Not published ; figured from advance plate of the Norwegian 

 North Sea Expedition. >S. Dalli appears to be a S. tortuosus 

 with well-developed spiral sculpture (see t. 51, f. 302-305); S. 

 undulatus is not adult. 



NEPTUNEA OSSIANI, Friele. PI. 87, fig. 621. 



Form similar to N. Turtoni, with yellowish brown, somewhat 

 scabrous epidermis. Length, 88 mill. 



Near Lofoten, Spitzbergen. 



The sculpture and epidermis, mouth and canal, are considered 

 different from N, Turtoni, and the shell is less solid. Cer- 

 tainly very closely related. 



Subgenus Mohnia, Friele. 



M. MOHNII, Friele. PI. 52, figs. 331. 332. 



White, subpellucid, epidermis thin, smooth or slightly hispid. 



Length, 22 mill. 



North Atlantic Ocean. 



The paucispiral opercultim is the distinguishing feature of this 

 species and subgcnus ; and I can scarcely believe that some error 

 has not occurred in assigning such an operculum to one of the 

 Buccinidae, because we are accustomed to consider this form as 

 evidence that the shell to which it belongs is holostomate. 



(Sonus SIPHONALIA, A. Adams. 



This genus is principally of tropical and subtropical distribu- 

 tion, and more highly colored than Neptunea : which, neverthe- 

 less, it approaches very nearly in the form and color of S. 

 Kellettii, for instance. The metropolis of the genus is Japan, a 

 few forms being found, however, on the opposite shores of the 

 West Coast of North America ; some species occur also in Aus- 

 tralian waters. The shells are usually thin and ventricose, varie- 

 gated in color, and destitute of epidermis. The operculum is 

 fusoid. 



A number of the species have been recently described by Mr. 

 Arthur Adams and others, the diagnoses being unaccompanied 



