34 PRTENE. 



T. CANCELLATUS, Lam. PL 16, figs. 164-167 ; pi. 17, figs. 170-172. 



Varying from cancellated to coarsely decussated surface, in 

 the latter the intersections of the longitudinal and revolving striae 

 frequently rounded nodulous. The epidermal fringe upon the 

 nodules is sometimes half an inch in length. 



Length, 3 to 4-5 inches. 



Straits of Magellan, Chili, Oregon, Alaska, Japan. 



I agree with P. P. Carpenter that T. Oregonensis, Red field 

 (fig. 167), is synonymous with this species ; the want of the ridge 

 upon the upper part of the columella by which Mr. Redfield dis- 

 tinguishes his species, being in consequence of the juvenility of 

 his type specimen. The variation in the sculpture which, in his 

 type, may have supported the view of specific distinction, includes 

 every intermediate stage in specimens before me, and in some of 

 them, a portion of the shell is rudely cancellated whilst another 

 portion is smoother and more finely decussated. The northern 

 distribution of T cancellatus is undoubted, but its occurrence 

 upon the southern coast of South America is not so certain, 

 although probable. 



The male (figs. 171, 172). and female (fig. 170). of this species 

 are, according to Gould, distinguished by their coloration ; the 

 shells also differ somewhat in form. 



T. SCABER, King. PI. 16, fig. 168. 



Varies like T. cancellatus in the closeness and prominence of 

 its sculpture. The internally toothed lip and closely bristled, 

 persistent epidermis are quite characteristic of the species. 



Length, 1'5 to 2*25 inches. 



Valparaiso, (7 to 45 fathoms) northwards to the coast of 

 Bolivia ; Arctic America to California. 



T. RUDIS, Brod. PL 16, fig. 169. 



Whitish, with a yellowish brown, close, rather persistent epi- 

 dermis. Length, 1'5 to 2 inches. 



Chili ; Iquiqui, Peru, in mud and sand, 6 to 10 fathoms, 



and in coarse gravel, 9 fathoms (Cuming\ 



