COMPLETE HAIG: EASTERN PACIFIC PORCELLANIDAE 241 



just behind the three distal ones; in one specimen, the male from 

 Bahia de Tepoca, the extra spinule was developed on one leg only and 

 was much smaller than the other spinules on the same leg. The structure 

 of the fixed spines on the dactylus is much as in P. quadritingulatus, 

 except that the two distal ones are nearly conjoined. 



The Gulf of California population may be readily separated from 

 the California and western Baja California population on the basis of 

 these characters, provided that they prove to be constant when larger 

 samples become available for examination. The differences are so rel- 

 atively slight that the two populations might better be considered sub- 

 species of a single species. It seems advisable to retain them both as 

 full species for the present, pending an analysis of the differences in 

 several other very closely related forms. 



Remarks: According to Lockington (1878), the single specimen of 

 Polyonyx nitidus was collected by Fisher at an unspecified locality in 

 Baja California; in the same paper he mentioned other porcellanids 

 taken by Fisher on both sides of the peninsula. The type of P. nitidus 

 is no longer extant and its identity with one population or the other 

 can never be established. Therefore, the type locality is hereby restricted 

 to "east coast of Baja California" so that the name nitidus may be ap- 

 plied to the Gulf of California population. 



The original description of Polyonyx nitidus applies equally well 

 to specimens of both populations. According to Lockington, the cheli- 

 peds in the type were "equal," but this is not the case in normal speci- 

 mens of either P. nitidus or P. quadriungulatus. The type of P. nitidus 

 may have been atypical, perhaps a specimen with a regenerating major 

 cheliped. 



Range: Gulf of California, from Bahia de Tepoca south to Isia 

 Ceralvo. 3 to 21 fathoms. 



