84 PRTENE. 



T. CANCELLATUS, Lam. PI. Ifi. figs. 104-167 ; 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. 



Straitx of Magellan, Chili, Orerion, Ala/<ka, Japan. 



I agree with P. P. Carpenter that T. Oregonensis, Redfield 

 (fig. 1(57), is synonj^mous with this species ; the want of the ridge 

 upon the upper part of the columella b}^ 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 

 t\'pe, 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 

 jjoi'tion is smoother and more finely decussated. The northern 

 distribution of T cancellatus is imdoubted, 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 b}^ their coloration ; the 

 shells tdso 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 (luite characteristic of the species. 



Length, 15 to 2*2.5 inches. 



VdlparaiKo, (7 to 45 fathoms) northwards to the roast of 

 Boliria ; Arctic America to California, 



T. RUDis, Brod. I'l. IC, lig. 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\ 



