WRINKLED SWIMMING-CBAB. 95 



toothed, the teeth curved, and directed forwards ; the 

 latero-posterior margin abruptly narrowed behind the pos- 

 terior lateral tooth. The first pair of feet somewhat un- 

 equal, the surface rugose ; the wrist with a long sharp 

 spine at the anterior and superior angle ; the hand with a 

 sharp carina on the upper side, terminating in a sharp 

 tooth over the joint of the finger ; claws longitudinally sul- 

 cate, the superior curved, the margins furnished with nu- 

 merous tubercular teeth, of which those of the larger claw 

 are larger and irregular, those of the smaller regular and 

 small ; the second, third, and fourth pairs of feet hairy 

 at the upper and lower edge, carinated above, and with 

 elevated lines along the sides, the terminal joint long, 

 slender, and styliform ; the posterior feet with elevated 

 lines on the sides of each joint, the margins of the joint 

 ciliated, the terminal joint rather narrow, lanceolate, and 

 mucronate. The sternum is slightly rugose. The abdo- 

 men in the male is triangular, in the female ovate ; the 

 first to the fourth joints strongly carinated transversely ; 

 the terminal joint forming an equilateral triangle. 



In. Lines. 

 Length of the carapace . . . . . 1 .5 



Breadth ...... 18 



The colour is reddish brown, often spotted with a 

 brighter red. 



The characters of P. corrugatus are so strongly marked 

 as to preclude the possibility of its being confounded with 

 any other species. It belongs to the same section of the 

 genus as P. puher^ and P. Rondeldii, characterised by ele- 

 vated lines on the sides of the terminal and penultimate 

 joints of the fifth pair of feet, a character which, associated 

 as it is with a narrower form of these parts, would seem 

 to indicate a somewhat inferior power of swimming. 



