1900.] ON CRUSTACEANS EBOM THE FALKLAND ISLANDS. 517 



brain-case is a product of the union of distinct ethnio- and oto- 

 sphenoidal cartilages, and its fenestras are primary. The trabecule 

 represent a pair of pre-oral visceral arches, and the epipterygoid 

 bone is an ossification of the ascending process of the pterygo- 

 quadrate cartilage. The columella auris and stapedial processes 

 are at all stages continuous with the hyoid arch, and that is at- 

 tached only to the quadrate above. The meeting of the pterygoids 

 and vomers is of an order leading to the Chelonia and Plesiosauria, 

 and the pterygo-quadrate cartilage closely resembles that of Ichtliy- 

 ophis. The " abdominal ribs " arise by numerous calcifications and 

 their median segment may be paired. There is no supra-temporal 

 bone present at any stage. The hip-girdle is simpler than in the 

 Lacertilians, and two types of pelvis are represented. There is no 

 trace of the fifth tarsale in the ontogeny, and while a centrale is 

 incorporated in the " astragalus,'" there are three centralia carpi 

 represented during development. 



Two types of cheek-teeth, and sustentacular ligaments which 

 support the medulla and spinal cord, were also described. 



This paper will be published in the Society's 'Transactions.' 



The following papers were read : — 



1. On some Crustaceans from the Falkland Islands collected 

 by Mr. Rupert Vallentin. By the Rev. Thomas R. R. 

 Stebbing, M.A., F.R.S., F.L.S., F.Z.S. 



[Keceived March 24, 1900.] 



(Plates XXXVI.-XXXIX.) 



The materials on which this paper is founded were collected by 

 Mr. Rupert Vallentin, F.L.S., in Stanley Harbour and the adjacent 

 district during the closing weeks of 1898 and the opening weeks of 

 the following year. During the course of the present century 

 this locality has been visited by several important scienlitic ex- 

 peditions. It may be worth while to mention the voyage of ' La 

 Coquille ' under Duperrey in the years 1822-1825, the Crustacea of 

 which were described by Guerin-MeneviUe between 1828 and 1838 ; 

 the voyage of ' L'Astrolabe ' and ' La Zelee ' under Dumont d' Urville, 

 3 837-1840, Crustacea by Jacquinot and Lucas, 1S42-1853 ; the 

 United States Exploring Expedition under Wilkes, 1838-1842, 

 Crustacea by Dana, 1 84G-1855 ; Voyage of the ' Erebus ' and ' Terror ' 

 under Sir J. C. Ross, 1839-1843, Crustacea by Miers, 1874 ; 

 the ' Challenger' Expedition, 1873-1876, Crustacea by several 

 writers, 1880-1888. Crustacea from the vicinity have also been 

 described by R. O. Cunningham in 1871, by Targioni-Tozzetti in 

 1877, and by Professor Studer in 1884. Consequently the general 

 features of the zoology of the Falklands are tolerably well known. 



