A WARM-TEMPERATE MARINE FAUNA 21 



with which I am most familiar, but they illustrate the points to be 

 made as well as could be desired. Of the short-tailed crabs the genus 

 Cancer, because of its commercial importance, is perhaps the best known. 

 Its center of distribution is the North American west coast, with nine 

 species present. Of these two, Cancer magister and C. oregonensis, occur 

 from Alaska to Central California ; f^ve, C. productus, C. antennarius, 

 C. branneri, C. jordani, and C. gracilis, extend varj^ing distances both 

 north and south of Pt. Conception; while two, C. anthonyi and C. 

 amphioetus, occur exclusively south of Pt. Conception. The short-range 

 species indicate a subdivision of the boreal into cold- and warm-temperate 

 subregions, although the long-range species tend to obscure this. 



A second group of importance are the kelp crabs. Of the genus 

 Pugettia, represented in the American Pacific by five species, one, P. 

 gracilis, is exclusively northern, two, P. producta and P. richii, extend 

 both north and south of Pt. Conception, while two, P. dalli and P. 

 venetiae, are exclusively southern. The large kelp crab, Taliepus nut- 

 tallii, ranges from Santa Barbara to Magdalena Bay, and the small kelp 

 crab, Epialtus hiltoni, known previously from Santa Catalina Island and 

 Laguna Beach, has been found south to Magdalena Bay wherever surf 

 grass, Phyllospadix, occurs. As with the genus Cancer, the short-range 

 species define a cold- and a warm-temperate subregion. 



A third group of decapods are the pebble crabs. The genus Lophopano- 

 peus, as revised by Menzies (1948), is represented by L. bellus, which 

 ranges from Washington State to Mission Bay, with a sharp break at 

 Pt. Conception defining the subspecies L. bellus diegensis. A second 

 species, L. leucomanus, ranges from Channel Islands (Monterej-, Ix>ck- 

 ington) to Rosarito Beach. A third species, L. frontalis, ranges from 

 San Pedro to San Ignacio Lagoon and occurs in the Gulf of California. 

 Cycloxanthops novemdentatus ranges from Monterey Bay to San Martin 

 Island, Paraxanthias taylori from Monterey Bay to Magdalena Bay, and 

 Pilumnus spinohirsutus from San Pedro to Magdalena Bay. 



A fourth group of Brachjoira are the swimming crabs. Portunus 

 xantusii presents a typical warm-temperate range: Santa Barbara to 

 Magdalena Bay and Gulf of California. Other members of this genus 

 are tropical. 



Of the grapsoid crabs, Pachygrapsus crassipes occurs from Crescent 

 City to Margarita Island, outside ]\Iagdalena Ba}-, and in the northern 

 Gulf of California. Among the oxystomatous crabs Randallia ornata 

 ranges from Mendocino Bay to Magdalena Bay. Of the parthenopid 

 crabs Heterocrypta occidentalis has been taken from Half Moon Bay 



