MAZATLAN UNIVALVES 349 



Sab. "Sitcha, Mexico and San Salvador," Philippi. Sitcha 

 and New Albion, Barclay, (teste Midd. sed v. supra.) 

 Panama & Taboga ; extremely common on ledges and large 

 fragments of rocks at or above high water mark ; C. B. Ad- 

 ams. Mazatlan ; common ; Melchers. Do. not uncommon ; 

 L'pool fy Havre Coll. 



Tablet 1657 contains 6 sp. compact form. 1658, 6 do. nor- 

 mal shape. 1659, 6 do. more elevated. 1660, 6 do. elongated. 

 1661, 5 do. much elongated. 1662, 4 sp. ventricose. 1663, 

 2 do. ribs distant. 1664, 4 do. ribs close. 1665, 2 do. abnormal 

 growth. 1666, 6 young sp. ribs very fine. 1667, 6 young sp., 

 P. apicina, Mice. 1668, 6 do. elevated, approaching L. Philippii. 

 1669, 3 separate opercula (others in their shells.) 



Tablet 1670 contains 3 very young Litorinse, the smallest 

 '03 by '024, the largest '088 by '055, probably belonging to 

 this species, but too young to identify with confidence without 



J^. 398. LITOKINA PHILIPPII, n. s. 



L. t. inter "Z. asperam" et "L. zic-zac" intermedia ; parvd, 

 compactd, interdum elevatd, plerumgue gibbosd ; anfr. subplan- 

 atis s ad basin angulalis ; colore livido, seu olivaceo- livido, 

 olivaceo-fuscd oblique strigatd ; lineis irregularibus, interdum 

 zic-zac-formibus, interdum interruptis, tesselatis : totd super- 

 Jicie nitentiore, sulcis subdistantibus subimpressis ornatd ; colu- 

 melld excavatd ; intus fused, margine acuto labri plus minusve 

 lineato ; nucleo plerumque eroso ; operculo tenuiore, latiore ; 

 intus nucleo nix elevato ; imp. muse, niinutissime scabro, lineis 

 incrementi conspicuis, suturd spirali haud celatd. 



This unpretending little species may be the L. aspera, var. 

 "more slender, sculpture reduced to spiral impressed lines" 

 of Prof. Adams. It may also form a part of the L. apicina of 

 Menke ; but as its usual character is just the contrary of his 

 diagnosis, being almost always eroded even in very young 

 specimens, it would have been scarcely truthful to retain the 

 name which he provisionally gave, apparently to the young of 

 L. aspera. The markings in this species, (which in L. conspersa 

 are purplish brown dots, and in L. aspera umber spots) are 

 olive brown, almost always in slanting lines more or less 

 interrupted ; and when broken up into dots, these are always 

 square, tesselating the spaces between the spiral lines. It i& 

 Oct. 1856. gg 



