NO. 8 HANNA AND HERTLEIN : MOLLUSCA 133 



Nine living specimens of Auricula were collected by Hertlein of the 

 Hancock Expedition from beneath the bark of a fallen palm tree near 

 the creek in Arroyo del Genio, which drains into Wafer Bay. They 

 were found about 50 meters above the outlet of the creek. The water 

 was apparently entirely fresh, at least during the ebb tide. The shells 

 are uniform in size, about one half as long as those from the Galapagos 

 Islands and the spire is much shorter. The series of spiral markings 

 just below the suture is much stronger than in the specimens of stag- 

 nalis which we have examined. The shape is very similar to the species 

 pellucens from Florida and the West Indies and if it were not for the 

 known great variation of stagnalis we would not hesitate to identify 

 the Cocos Island shells with the east coast species. 



Melampus panamensis (C. B. Adams) 



Auricula panamensis C. B. Adams, Ann. Lyceum Nat. Hist. New 

 York, vol. 5, July, 1852, pp. 433, 542. "Panama and Taboga. 



600 spec." Reeve, Conch. Icon., vol. 20, 1878, Auricula, 



sp. 59, pi. 7, fig. 59. ''Hab. Jamaica." 



Alelampus panamensis (C. B. Adams), Pfeiffer, Monogr. Auric. Viv., 



1856, p. 48. Dall, Proc. Acad. Nat. Sci. Philadelphia, vol. 



52, 1900, p. 97. Cocos Island. von Martens, Biol. Cen- 



trali-Americana, Moll., 1900, p. 561, pi. 43, figs. 10, \0a. Previ- 

 ous records cited. Dall, Bull. Mus. Comp. Zool., vol. 43, 



no. 6, 1908, p. 436. Cocos Island. 



Tralia panamensis (C. B. Adams), Dall, Proc. Acad. Nat. Sci. Phila- 

 delphia, vol. 48, 1896, p. 452. Cocos Island. 



This species is not represented in our collections from Cocos Island. 

 It is a slender shell with a high, sharply pointed spire, apparently one of 

 the most distinct of this genus on the west coast. The color is dark 

 reddish brown and the spire has a few faint spiral striations. For diag- 

 nostic characters, reliance must be placed almost entirely upon Adams' 

 description and von Martens' excellent figure. Its presence on Cocos 

 Island rests upon the authority of Dr. Dall. 



Melampus tabogensis (C. B. Adams) 



Auricula tabogensis C. B. Adams, Ann. Lyceum Nat. Hist. New York, 

 vol. 5, July, 1852, pp. 435, 542. "Taboga and Panama. 800 



