1921] Schmitt: The Marine Decapod Crustacea of California 281 



IV. DISTRIBUTION 



Geographical. 1 — Of the one hundred and eighty-one marine deca- 

 pods known to occur within the 100 fathom line off the coast of 

 California, forty-two (23%) are found on the west coast of North 

 America only within that area, fifty-nine (33%) range from Cali- 

 fornia northward, fifty-three (29%) range southward, and twenty- 

 seven (15%) range both north and south. 



The species confined to California waters on the North American 

 coast are : 



Palacmonetes hiltontf Cyclodorippe plana 



Pontonia calif or niensis\ Loxorhynchus grandis* 



Pandalus gurneyi Loxorhynchus crispatus* 



Hippolysmata califomica^ Cycloxanthops rugosus^ 



Spirontocaris affinis° Lophopanopeus frontalis^ 



Spirontocaris lagunae-f Lophopanopeus heathii 



Spirontocaris franciscana Lophopanopeus leucomanus 



Spirontocaris carinata Lophopanopeus diegensis 



Spirontocaris picta Xanthias latimanus^ 



Crangon barbara^ Speocarcinus calif orniensisj 



Crangon equidactylus Pinnotheres nudus" 



Betaeus harfordi Pinnotheres holmesi" 



Betaeus longidactylus^ Fabia lowetf 



Nectocrangon calif orniensisj Fabia canfieldi° 



Axiopsis spinulicauda° Parapinnixa affinisj 



Callianassa affinis\ Pinnixa longipes 



Paguristes parvus] Pinnixa franciscana 



Holopagurus pilosus Pinnixa hiatus'} 



Pagurus samuelis Pinnixa weymouthi" 



Pachycheles holosericus Opisthopus transversus 



Petrolisthes rathbunaej Grapsodius eximius^ 



Except Pagurus samuelis, all of the above are peculiar to Cali- 

 fornia. 



More than one-half, thirty-three (56%), of the fifty-nine species 

 ranging northward find their northern limits along the Alaska coast, 



i As noted in the Introduction this discussion deals only with the littoral fauna. 

 The forms which have been included and which possibly do not properly belong 

 here are the seven cited as "pelagic" or "with a bathvmetric range of more than 

 500 fathoms," (p. 285) all or in part. 



The species taken in connection with the Biological Survey of San Francisco 

 Bay are printed in bold face type; those reported from the region covered by the 

 survey but not taken during it are marked with an * ; those found only north 

 of Point Conception are indicated by a ° ; and those found only south of that 

 point on the west coast of America are marked with a f. The species lacking 

 either of these last two signs naturally range both north and south of Point Con- 

 ception. 



The northern limits of seven species are somewhat doubtful, but owing to the 

 fact that they are so few in number (4%) and in order to avoid unnecessary 



