134 PROCEEDINGS OF THE ACADEMY OP 



and between the two angles are two rounded prominences. The 

 superior surface presents a well-marked ridge with a sulcus on 

 each side of it. 



The ambulatory feet are hairy : the third article is broad, com- 

 pressed, and imbricated. The color of the carapax and cheliped 

 is reddish. The length of the carapax is .025 of an inch. 



Petrolisthes jugosus, Nov. sp. 



The carapax is rotundo-ovate in outline, about as broad as long, 

 depressed, and smooth, or very lightly granular under the micro- 

 scope. The front is deflexed and trilobate. The lobes are rounded ; 

 the middle one is more prominent than the lateral ones. There is 

 a well-marked median furrow extending to the tip of the middle 

 lobe ; and a furrow on each side which terminates at the anterior 

 border of the lateral lobes. The anterior border of the front pre- 

 sents a well-defined raised margin. The superior border of the 

 orbits is not inflated. The external angle is obtuse and not pro- 

 minent. The eyes are large ; the first article of the antennary 

 peduncle has a projection on its anterior border. 



The chelipeds are large, compressed, and granular ; the left is 

 larger than the right. The hand is as long as the carapax. Its 

 width is greater at its junction with the dactylus than where it 

 articulates with the carpus. The posterior border is pubescent. 

 The posterior part of the superior surface is broadly grooved, and 

 this groove is continued on the propodus. The anterior part of 

 the upper surface presents another slighter groove ; and a broad 

 ridge runs longitudinally along the centre of the same surface. 

 The carpus is shorter than the hand, and its anterior margin is 

 armed with five small teeth. Its upper surface is marked by three 

 longitudinal ridges. The posterior and external borders are di- 

 lated. The anterior angle of the merus is armed with a tooth. 



The ambulatory feet are pubescent, and minutely granulated 

 under the microscope. The third article is compressed ; the fourth 

 and fifth articles are ridged on their upper surfaces, in their long 

 direction. The color is a reddish shade; the chelipeds are more 

 deeply colored than the carapax. The length of the carapax is 

 .019 of an inch. 



MACROURA. 



Palemon Jamaicensis, Olivier. H. Milne-Edwards. Hist. Nat. des Crust., 

 Vol. II. p. 398. 



