EEPORT OF THE SECRETARY. 35 



fact, along the coast aud in the low valleys very few species other than 

 ordinary sparrows, humming- birds, &c, can be obtained. Owing to the 

 bold, precipitous character of the island coast and the absence of small 

 outlying islands or detached rocky islets, Mr. Ober found that only a 

 few sea birds were resident. 



As far as known, the most significant result of Mr. Ober's collection 

 and investigation of the avifauna of the Lesser Antilles is embodied in 

 the statement that each one of these several little islands constituting 

 that group has one or more species peculiar to itself alone. 



Mr. W. II. Dall has contributed several papers to the Proceedings, de- 

 scribing new forms of mollusks, both recent and belonging to the Ter- 

 tiary formation, nearly all of which are from the western coast of the 

 United Slates, several being particularly interesting. One of these 

 forms was brought up ou a sounding line by Oapt. Geo. E. Belknap, of the 

 U. S. S. Tuscarora, on his celebrated sounding expedition from Japan to 

 California via the Aleutian Islands, in 187f . This mollusk, a species of 

 Chiton, came from a depth of G,0GG feet below the surface, a much greater 

 depth than that in which any other species of the genus has yet been 

 known to exist. Many of the other shells and fossils described were due 

 to the exertions of Mr. Henry Hemphill, of California, whose ability as 

 a collector stands unrivalled, and who kindly presented those objects, 

 which he believed to be new, to the National Museum. 



Small but interesting collections of shells from " Kitchen Middens," 

 on the Pacific coast of Costa Eica, were also identified by Mr. Dall. 

 These species, collected by l)rs. Flint and Bransford, are still found liv- 

 ing in adjacent waters, and are now used for food by the natives. 



Mr. Dall also contributed a paper on the Limpets and Chitons of the 

 Alaskan region, with descriptions of genera and species believed to be 

 new. This was illustrated by five plates, representing chiefly the teeth 

 of these animals, worked out by microscopical investigations of his own. 

 Some forty-two forms were figured, only three or four having previously 

 been known. The paper contains a review of the general classification 

 of the Chitonidce, based on the researches of P. P. Carpenter and the 

 author, together with a summary of the known facts in regard to the 

 anatomy and development of these animals, some of which are here 

 stated for the first time. A number of genera and subgenera, proposed 

 by Dr. Carpenter in his unpublished monograph of the Chitonidcv, to- 

 gether with others heretofore only partially characterized, are here fully 

 described for the first time. 



Mr. R. Pidgway has contributed the following: 



(1) On a new humming-bird (Althis ellioti) from Guatemala (pp. 8-10). — 

 Certain constant differences, previously overlooked by authors, between 

 specimens of Atthis heloiscc (Less. & Delattr.) from Mexico and the 

 birds from Guatemala referred to that species are pointed out and illus- 

 trated by outline figures. The Guatemalan bird is characterized as a 

 new species, and named in honor of Mr. Daniel Giraud Elliot, the well 

 known ornithologist, and a special authority on this family of birds. 



