OCR Text |
Show 1900.] ON CRUSTACEANS FROM THE FALKLAND ISLANDS. 517 brain-case is a product of the union of distinct ethmo- and oto-sphenoidal cartilages, and its fenestree 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 attached only to tbe 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 Ichthy-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 M r . Bupert Vallentin. By the Rev. T H O M A S B. R. S T E B B I N G , M.A., F.R.S., F.L.S., F.Z.S. [Eeceived March 24, 1900.] (Plates XXXVI.-XXXIX.) The materials on which this paper is founded were collected by Mr. Eupert 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 scienliKc expeditions. 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-Meneville between 1828 and 1838 ; the voyage of 'L'Astrolabe' and' L a Zelee' under Dumont d'Urville, 1837-1840, Crustacea by Jacquinot and Lucas, 1842-1853; the United States Exploring Expedition under Wilkes, 1838-1842, Crustacea by Dana, 1846-1855; Voyage of the' Erebus' and' Terror' under Sir J. C. Boss, 1839-1843, Crustacea by Miers, 1874; the s Challenger' Expedition, 1873-1876, Crustacea by several writers, 1880-1888. Crustacea from the vicinity have also been described by E . O. Cunningham in 1871, by Targioni-Tozzetti in 1877, and by Professor Studer iu 1884. Consequently the general features of the zoology of the Falklands are tolerably well known. |