PKOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 341 



them are too great. Consequently, all the members of their land fauna 

 and flora must be considered as immigrants brought by currents, float- 

 ing wood or ice, migratory birds, and man. The foxes which inhabited 

 the islands when first discovered undoubtedly reached them on floating 

 ice-fields, as a certain kind of rat or marmot is known to have done one 

 of the Western Aleutians, and as the polar bear almost annually reaches 

 the island of St. Mathew. 



Conchologically, next to nothing has been known about the Com- 

 mander Islands. It is true one of the most remarkable of the mollusks 

 of Nortliwest America, and the first mollnsk described from that region 

 was found by Steller at Bering Island,' namely, Cryptochiton stelleri of 

 later writers, which is fully described under its Kamchatkan name of 

 " Keru" in his " Kamchatka, '^ page 177. Since then a few references 

 have been made to species collected by Wossnessenski from Bering- 

 Sea, part of which were probably obtained at the Commander group,, 

 and the presence of Vitrina is noticed in the " Voyage of the Vega " 

 from whose collections Westerlund has described some mollusca else- 

 where referred to. This appears to be all at present on record in re- 

 gard to the molluscan fauna of the group, at least my search has not 

 revealed anything else, though it is possible some isolated references 

 have been overlooked. The references of Schrenck and Middendorff 

 are of a general character, and they give no separate list for these isl- 

 ands. 



CEPHALOPODA. 



Octopus punctatus Gabb. 



This widely distributed Pacific species was obtained, October 9, at 

 Avatcha Bay, Kamchatka. The specimen is of moderate size. Col- 

 lector's number, 2759. Mus. Cat. 40903. 



Gonatus amoenus Verrill. 



A single not very well preserved specimen, collected June 6, is re- 

 ferred by Professor Verrill to this species. Bering Island; collector's 

 number, 1163. Mus. Cat. 40904. 



GASTEOPODA. 



I 



Kudibranchiata. 

 ^olidia papulosa (L.) Bergh. 



One specimen at Bering Island in the spring of 1883, collector's num- 

 ber, 2349. ]\Ius. Cat. 40905. ThreeHpecimensofLcmelUdorisbiUameUata 

 L. var. Pacifica Bergh, were also collected, October 1, at Avatcha Bay, 

 Kamchatka ; collector's number, 2733. Mus. Cat. 40906. 



Pulmonata. 

 Limax hyperboreus Westerlund. 



This small species, widely distributed about Bering Sea, was obtained 

 at Bering Island ; collectors' numbers, 1400, 1509, and 2409. Mus. Cat. 



