THE MARINE FAUNA OF THE FALKLAND ISLANDS. 81 



Of the 4 species of this genus known : — 



I. 0. vivipwra is only found in the southern hemisphere. 

 II. 0. australis occurs in South Australia and south temperate 

 region as well as the tropics. 



III. 0. flaccida occurs off Bahia and off Bermudahs, i.e., in south 



tropical and north temperate zone. 



IV. 0. pentctgona occurs only in the northern hemisphere. 



From the preceding one may conclude that, while the genus is widely 

 distributed in temperate and tropical regions, the species, though over- 

 lapping each other to a certain extent, are somewhat limited in their 

 distribution. 



Of 6 representatives of the Echinoderms in the collection, 3 species 

 ore pecular to South America, 2 of which are found in the Strait of 

 Magellan, as well as the Falklands ; one is peculiar to the Falkland 

 Islands. Two species are apparently distributed over the southern 

 hemisphere, one of them extending beyond the Equator to the north 

 temperate region. 



BRACHYURA. 



a) Catometopa. 



PlNNOTHERIDjE. 



Halicarcimis planatus White, Ann. Mag. Nat. Hist., 

 Vol, XVIII., 1846, p. 178, is widely distributed over 

 the Antarctic region, and is said. to be the only Brachy- 

 urous Decapod proper to that wide area of distribution 

 (Stebbing, Crustacea), 

 (b) Cyclometopa. 

 Cancrinea. 



CANCRIDiE. 



Xantlio crenatus Milne Edwards, Crustacea Vol. I., 

 p. 396. Coasts of Peru. New to Falklands. 

 MACRURA. 

 Anomura. 

 (a) Lithodea. 



Lithodid^e. 



Paralomis verrucosus Dana, U.S. Expl. Exped., XIII., 

 Crust., Pt. 1, p. 428. Falklands. Common in E. 

 portion of Strait of Magellan, not further W. than C. 



