440 MAZATLAN UNIVALVES 



a brownish white. In a genus the species of which present so 

 few peculiarities, it is not thought prudent to describe it. It 

 seems to have nine whirls, and measures long. ' 115, long. spir. 

 075, lat. '045, div. 23. 

 Hob. Mazatlan ; 1 sp. off Spondylus ; L'pool CoL 



553. ? LEIOSTEACA , sp. ind. (b.J 



Tablet 2024 contains a short stumpy shell ; with the apex 

 decollated. It appears to have been brown, and displays a 

 continuous peritreme. It bears some resemblance to the 

 W. Indian L. fulvocincta, C. JS. Ad. Contr. Conch, no. 7, p. 111. 

 It has four whirls, and measures '077 by "035. 

 Hob Mazatlan ; 1 sp. off Spondylus ; Lpool Col. 



554. LEIOSTEACA LINEAEIS, n. s. 



L. t. minima, gracillimti, alba ; axi recta; apice acuta ; 

 anfr. ix., primo decliviore ; nitente, mx varicosa ; apertura 

 pyriformi, continue ; labio rimulam umbilicalem formante ; 

 columelld liaud callosa. 



Distinguished by its minute size, and extremely slender 

 growth. The habit is that of Leiostraca, though the varices 

 can scarcely be traced. Long. '072, long. spir. '05, lat. '022, 

 div. 15. 

 Hob. Mazatlan ; 1 sp. off Spondylus ; L'pool Col. 



Tablet 2025 contains the specimen. 



555. LEIOSTEACA PIOTA, var. EETEXTA. 



Comp. Eulima iota, C. B. Ad. Pan. Shells, no. 290, pp. 198, 



317. Sow. Thes. Conch, in loco. R. $ A. Ad. Gen. i. 236. 

 L. ?iota, axi recta. 



The form above indicated accords somewhat better with 

 the Panama species than with the British, but is entirely 

 without twist. The British specimens are also sometime 

 straight. The shells in this genus afford so very few distinctive 

 characters that no species can be certainly established without 

 an accurate knowledge of the animals. The only two specimen 



