254 MAZATI.AN UNIVALVES 



size, and there were no intermediate specimens, I have not ven- 

 tured to affiliate them. It differs from T. politum in the 

 absence'of sculpture, (which however would hardly be detected, 

 even under the microscope, without the description,) in the 

 greater reflection of the labrj.m over the spire, and in the very 

 much smaller size. Long. '05, lat. '11 by *07, div. 180. 

 J?a5. Mazatlan ; 1 sp. and fragment off Spondylus ; IS pool 



Col. 



Tablet 1174 contains the specimen. 



324. TEINOSTOMA SUBSTEIATTTM, n. s. 



T. t. minima, planatd, opacd, alba, subnitente ; striulis 

 spiralibus prope suturam impressam monstrantibus ; callositate 

 angustissimd, longiore, circa rimam umbilicalem gyrante, prope 

 labium vix planato ; aperturd rotundatd ; labro solido, anfr. 

 penult, baud amplectante. 



Thig tiny species is known from T. amplectans by the outer 

 lip not being reflected over the spire, which clearly displays 

 the substriated whirls. The callosity is long, but narrow, and 

 scarcely planate at the aperture. A fragment has the suture 

 less impressed. Long. '016, lat. *043 by "032. div. 170. 

 Hob. Mazatlan ; 1 sp. (not quite perfect) and a fragment ; 



Lpool Col. 



Tablet 1175 contains the specimen. 



325. TBOCHUS , sp. ind. 



Tablet 1176 contains a fragment of a white shell, tuberculous, 

 with the basal keel smooth j found in additional materials 

 after the genus had been completed. 

 Hob. Mazatlan ; extremely rare, off Spondylus j Lpool Col. 



Tablet 1177 contains an operculum not affiliated to any 

 known multispiral species. (That of species 291 is however 

 unknown.) It is light horn-coloured, extremely thin, with 

 only about 10 whirls ; margin irregular ; scar lateral, 



Tablet 1178 contains 2 worn, small, strong, Turbinoid oper- 

 cula, remarkable for the number of whirls, there being at 

 least 10 in a diameter of *046. 



