251 MAZATlAK 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 labrum over the spire, and in the very 

 much smaller size. Zoiig. "05, laf. '11 by '07, div. 180". 



Sab. — Mazatlan ; 1 sp. and fragment off Spondylus ; L'pool 

 Col. 



Tablet 1174 contains the specimen. 



324. Teinostoma substbiatum, n. s. 



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

 spiralibus prope suturam impressam monstrantibus ; callositate 

 angustissimd, longim'e, circa rimam umbilicalem gyrante, prope 

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

 penult, hand amplectante. 



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

 hp 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. Lo7ig. '016, lat. "043 by ■Ql^2. div. 170°. 



JIab. — ilazatlan ; 1 sp. (not quite perfect) and a fragment ; 



L'pool Col. 



Tablet 1175 contains the specimen. 



325. TfiocHrs , sp. ind. 



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

 with the basal keel smooth ; found in additional materials 

 after the genus had been completed. 



Mab. — Mazatlan ; extremely rare, ofi Spondylus ; L'pool 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, extremcl^^ thin, with 

 only about 10 whirls ; margin irregular ; scar lateral. 



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

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

 least 10 in a diameter of "016. 



