22 GARTH 



to Dewey Channel, opposite Pta. Eugenia. The range of Podochela 

 barbarensis, Pt. Mugu to Pta. Abreojos and Gulf of California, is warm- 

 temperate, while a spider crab of limited range is Libinia setosa, found 

 from San Juanico Bay to Magdalena Bay only. 



Enough examples have been given to establish point one, that the 

 region from Pt. Conception to Pta. Entrada, outside Magdalena Bay, 

 supports a large number of endemic species, which may be of either boreal 

 or tropical genera. Let us now proceed to compare this endemic fauna 

 with that of warm-temperate faunas of other continents and oceans. 



Having just completed a report on the Brach>aira of the Lund Uni- 

 versity Chile Expedition, I am perhaps best prepared to discuss the fauna 

 of northern Chile and Peru. Here Ekman (1953, p. 209) has no diffi- 

 culty in recognizing a warm-temperate fauna, the northern limit of 

 which he places at Pta. Aguja, Latitude 6° S (it will be remembered 

 that the boundary between temperate and tropical faunas occurs here 

 at a much lower latitude than elsewhere in the world), the southern 

 limit in the vicinity of Chiloe Island, Latitude 42° S. Below this the 

 Anti-boreal region extends to the tip of South America. But when we 

 compare the marine faunas of north Chile- Peru and Southern California- 

 northern Lower California, there can be no doubt that the tw^o regions 

 are analogous. 



After an absence from the tropical littoral the genus Cancer is again 

 strongly represented, with four species present. Of these two, C. edwardsi 

 and C. plebejus, are long-range species, extending southward to Trinidad 

 Channel and Port Otway, respectively, while two, C. porteri and C. 

 polyodon, are short-range species extending only to Valparaiso and Chiloe 

 Island, respectively. As in the Northern Hemisphere, the short-range 

 species define the warm-temperate region. 



The genus Pugettia is not represented in the Southeastern Pacific, 

 but the giant kelp crabs, genus Taliepus, are represented by two species 

 instead of one. T. dentatus, the long-range species, ranges from Callao, 

 Peru, to Port Otway, Alagallanes Territory, and perhaps to the tip of 

 South America, while T. marginatus, the short-range species, occurs 

 from Independencia Bay, Peru, to Talcahuano and Guayacan, Chile. 

 T. marginatus is therefore the analogue of T. nuttallii, the single, short- 

 range species of North America. 



Among the pebble crabs, Cycloxanthops sexdecimdentatus, ranging 

 from Paita to Chinchas Islands, Peru, is the analogue of the northern 

 C. novemdentatus. The genera Lophopanopeus, Paraxanthias, and Pilum- 

 nus are absent. 



