A WARM-TEMPERATE MARINE FAUNA 23 



Among the grapsoid crabs the genus Cyclograpsus occurs with two 

 species, C. crenatus, San Lorenzo Island, Peru, to Lota, Chile, and C. 

 punctatus, even more restricted on the mainland but occurring also at 

 Juan Fernandez Island. The single northern species is C. escondidensis 

 of the Gulf of California. 



There is no short-range Portunus on the South American west coast 

 corresponding to P. xantusii of California-Lower California, and no 

 oxystome corresponding to Randallia ornata. There is, however, a short- 

 range spider crab, Libinia rostrata of Peru, that is the counterpart of the 

 short-ranged L. setosa of the west coast of Lower California. 



Enough examples have been given to demonstrate that similar faunas 

 occur in Southern California-northern Lower California and in northern 

 Chile-Peru, and that if the latter is warm-temperate and is set oil from 

 the Anti-boreal, the former should be called warm-temperate and be set 

 off from the boreal as well. The bipolarity of twin species, according to 

 Ekman, is of particular importance because it indicates common origin 

 of comparatively recent date. Hubbs (1952) points out that most so- 

 called bipolar species are in fact biboreal or bitemperate, and argues ably 

 that it was during one or more Pleistocene periods of global cooling that 

 their transgression of the tropics occurred. 



A comparison of the fauna of Southern California-northern Lower 

 California with that of the Iberian Peninsula, which occupies a corres- 

 ponding position in the eastern North Atlantic, must await the study of 

 a collection of crabs sent from Cadaquez, Spain, on the Bay of Biscay, 

 by Dr. Zariquiey Alvarez. Suffice it to say here that, according to 

 Nobre (1936), two species of Cancer, C. pagurus and C. bellianus, 

 occur in Portugal, the latter in Madeira, the Azores, and Cape Verde 

 Islands as well. The balance of the paper will develop the affinities of 

 the region under discussion with the northern part of the Gulf of 

 California. 



The Gulf of California has its mouth well within the tropics, but 

 its head in the north-temperate zone. Long considered as supporting an 

 exclusively Panamic fauna (Cf. Steinbeck and Ricketts, 1941, pp. 306, 

 476), it has been shown recently by Hubbs (1948, p. 463) to have 

 California coastal types of fishes in its upper portion. The same may 

 be said for its crab fauna, as has been suggested above. Southern Cali- 

 fornia-northern Lower California species occurring in the northern 

 Gulf are Hepatus lineatus, Podochela barbarensis, Pilumnoides rotundus, 

 Pachygrapsus crassipes, and Uca crenulata. This relationship has been 

 greatly strengthened by as yet unpublished studies of the Scammon 



