Pacific Shores of North America. 27 



pachygrapsus crassipes. Randall. 



Pachygrapsus crassipes, Randall ; Jour. Acad. Nat. Sci. Philad. viii. 127. 



Distinguished by the square form of the carapax, which 

 has a single tooth on each side posterior to that forming the 

 outer angle of the orbit ; — the broad depressed front, and 

 spiny tarsi. It is very common on the coast of California, 

 south of San Francisco, and was found at the Farallone Is., 

 (Trowbridge;) at Monterey, (Taylor;) and at San Diego, 

 (Schott.) Randall states that his specimens were found 

 at the Sandwich Is., by Nuttall. But the species has never 

 been found there by other observers, although the Islands 

 have been frequently and well searched for Crustacea. On 

 the other hand, Randall states that his P. parallelus * is 

 found on the coast of Oregon, where, however, it has not 

 been since observed ; while it is common at the Sandwich 

 Is. It is therefore probable, that in the case of Nuttall's 

 specimens the labels of the two species were accidentally 

 exchanged. 



Mus. Bost. Soc. ; Phil. Acad. ; Smithsonian ; Acad. Pe- 

 trop. ; Paris. I 



There seems to be no good reason why Randall's name 

 Pachygrapsus should not be retained for the group called 

 Leptograpsus by Milne-Edwards. The thick, square, and 

 evidently allied forms with a square third article of maxilli- 

 peds, for which Dr. R. instituted the genus, are quite dis- 

 tinct from the true Grapsi, though forming a group to which 

 De Haan proposed to restrict the ancient name of the fam- 

 ily. When it was found necessary to divide this group 

 into genera, based upon the characters of the orbits and ex- 

 ternal antenna?, the name Pachygrapsus should certainly 

 have been retained for one of them. That Randall did 

 not describe the structure of those parts in his two species, 



* Gra.psua thukuhar, Owen ; Goniograpsus thukuhar, Dana ; Metopograpsus thu- 

 kuhar, Milne-Edwards, Melanges Carcinologiques, p. 131. 



