28 Crustacea and Echinodermata of the 



is no reason for rejecting it, — this was not necessary in the 

 definition of the group. As well might we reject the name 

 Grapsus itself, because we cannot determine from Lamarck's 

 descriptions many characters now considered important. 

 Randall's first-mentioned species, P. crassipes, which we 

 may consider as typical, is closely allied to the Mediter- 

 ranean Grapsus varius ; having the internal suborbital lobe 

 widely separated from the front, admitting the external 

 antennae within the orbit. It therefore belongs to M. Ed- 

 wards's division Leptograpsus. P. parallelus will come 

 under Mctopograpsus, which genus seems to be the nearest 

 ally of Lcptograpstts, although M. Edwards places Grapsus 

 between them. In fact, M. thuknhar might well be consid- 

 ered an intermediate species, for the suborbital lobe is here 

 not quite joined to the front, although approximating closely 

 to it. 



PSEUDOGBAPSUS OREGONENSIS. Dana. 



PBeudograpsns Oregonensis, Dana; U. S. Exploring Expedition, Crust, i. 334, 

 PI. XX. f. 6. Milnb-Edw ai:ds ; Mdlanges Carcinoloyiques, 157 '. Stimpson ; 

 Proc. Cat. Acad. Nat. Set. i. 88. 



The Pseudograpsi are easily distinguished from the other 

 Grapsi of this coast by the approximation of the inner mar- 

 gins of the outer maxillipeds, which, in the other forms, 

 are widely separated by a rhomboidal space. The present 

 species differs from the next in the hairiness of its feet. It 

 is bluish-gray above, clouded anteriorly with patches of 

 dark red dots ; the feet, with the exception of the light- 

 colored anterior pair, are sparsely dotted with red. The 

 carapax is usually about an inch in length. The lanose 

 spot on the hand is found in the male only. 



This species occurs very abundantly on the muddy shores 

 of sheltered bays, generally among pebbles and under stones 

 about half-tide mark. It was found in Puget Sound, (Suck- 

 ley ;) Tomales Bay, (Samuels ;) and in San Francisco Bay, 

 (Ayres.) 



