MAZATLAN UNIVALVES 177 



Helix (Cochlostyla) princeps, D'Orb. Synops. p. 8. 

 Orthalicus princeps, Beck. Ind. p. 59, no. 3. 

 Achatina pulchella, Spix. 



This well known and widely distributed species is the only 

 land shell which appears at all common at Mazatlan. It varies 

 greatly in pattern, as will be seen by the following list. Most 

 of the shells were young, but characteristic. The first 3 or 4 

 whirls rarely display any painting. Long. 2'1, lat. I'l. 

 Hob. Brazils, Peru, Columbia, D'Orbigny. Cuba, Sagra. 



Conchagua, Broderip. Mazatlan ; common ; L'pool Col. 



Tablet 796 contains 5 sp., with very large dark patches. 

 797, 4 do. patches diagonal. 798, 3 do. patches smaller. 799, 

 1 do. patches clouded. 800, 5 do. gathering into knots. 801, 

 7 do. normal painting, knotted in spiral bands. 802, 4 do. very 

 fine, scarcely zigzag stripes. 803, 3 do. irregularly crowded. 

 804, 4 do. knotted pattern extremely faint. 805, 3 do. yellow- 

 ish, with spiral brown lines at the base. 806, 1 sp. yellowish, 

 without pattern. 807, 5 sp. elongated form. 808, 1 sp. with 

 winter epiphragm. 809, 3 sp. broken and mended by the 

 animal. 



233. ORTHALICUS ZiEaLEKi, Pfr. 



Bulimus Ziegleri, Pfr. Proc. Zool. Soc. 1846, p. 113, no. 25 : 



Symb. no. 472. 

 Leiostracus Ziegleri, H. <$f A. Ad. Gen. vol. ii. p. 151. 



This shell is placed by Messrs. Adams in a subgenus of 

 Otostomus. It has however a sharp, non-reflected lip ; as well 

 as a very small, scarcely covered umbilicus. A very few speci- 

 mens were found with the Physse. An unusually large one, in 

 which the linear patches of colour are almost evanescent, 

 measures long. '69, long. spir. '35, lat. '34. 

 Hob. Central America, Largilliert. Mexico, Liebmann. 



Mazatlan ; extremely rare ; L'pool Col. 



Tablet 810 contains 2 sp., one of normal colouring, the other 

 the pale variety. 



234. OETHALICUS ? MEXICANUS, Lam. 



Bulimus Mexicanus, Lam. An. s. Vert. vol. viii. p, 232, no. 23. 



Vol. in Humb. Hec. Zool. 



Leiostracus Mexicanus, If. Sf A. Ad. Gen. ii. 150. 

 = Helix vittata, Daud. Hist. Moll. no. 397. 



