PINNOTHERHXfc 53 



Family PINNOTHERID^. 



The material in this family is not so extensive or satisfactory as that 

 in the case of the other families here treated, and for that reason no ex- 

 tended treatment is attempted. The following key to genera is in part 

 adapted from Miss Rathbun (Am. Nat., vol. xxxiv, p. 588). No specimens 

 of either Scleroplax or Cryptophrys were available for comparison ; the 

 key moreover is not intended to apply to other than coast forms. 



KEY TO THE GENERA OF PINNOTHERNXE FOUND IN MONTEREY BAY. 



a. Ischium of outer maxilliped rudimentary. 



b. Palp of outer maxilliped with three joints. 



c. Carapace with longitudinal sulci behind the orbits enclosing 

 the median area (legs slender, dactyls of similar length). 



Raphonotus 

 cc. Carapace without longitudinal sulci. 



d. Legs subequal, dactyls of last pair markedly longer than 

 those of preceding pair; carapace suborbicular. 



Pinnotheres 



dd. Legs subequal or markedly unequal, dactyls of last 

 pair always shorter than those of preceding pair; 

 carapace markedly wider than long. 

 e. Third ambulatory leg markedly longer than others. 



Pinnixa 



ce. Third ambulatory leg not markedly longer than 

 others. Scleroplax 



bb. Palp of outer maxilliped with two joints. Cryptophrys 



aa. Ischium and merus of outer maxilliped separate or incompletely fused. 



(Carapace suborbicular, convex, hard; legs stout.) Opisthopus 



Genus PINNOTHERES Latreille. 

 Pinnotheres Latreille, Hist. Nat. Crust., iii, 25, 1802. 



Pinnotheres nudus Holmes. 



Pinnotheres nudus Holmes, Proc. Calif. Acad. Sci., 2d ser. iv, 563, pi- xx, fig- i-5, 

 1895. Holmes, Occas. Papers Calif. Acad. Sci., vii, 86, 1900. Rathbun, H. A. 

 E., x, 185, 1904. 



