252 



ASTACIDJE. 



are not more than three or four in number ; the inner 

 pair converge towards the rostrum and pass into a 

 double carina which extends to its extremity. The rostrum 

 extends beyond the peduncle of the external antennse, and 

 is armed on each side with three oblong teeth ; it is ciliated 

 on each side beneath. The posterior portion of the thorax 

 has three lines of small points: a strongly marked sulcus 

 runs within the posterior margin. The eyes are remark- 

 ably large and reniform ; the peduncles very small at 

 their origin, becoming suddenly much larger. The pe- 

 duncle of the external antennse is nearly as long as the 

 rostrum : the first joint has a triangular spine at the outer 

 side ; from the anterior margin of this joint arises the 

 broad falciform scale, which extends forwards to the ex- 

 tremity of the peduncle. The basal joints of the inter- 

 nal antennae are very broad and laminar. The first pair 

 of feet are very long, unequal, in some cases the right, 

 in others the left being the larger : the arm is slender, en- 

 larging towards its anterior extremity, carinated above and 

 below, and armed with a few teeth : the wrist, which is 

 short, is armed above with strong teeth, and is strongly ca- 

 rinated: the hand is distinctly four-sided, strongly cari- 

 nated ; the carinse armed with tubercular teeth, the upper 

 in a single, and the others in a double series ; the interme- 

 diate spaces concave, and slightly pubescent : the fingers are 

 armed with strong tubercles, particularly those of the larger 

 claw, and the moveable one is toothed on its outer mar- 

 gin. The other legs are filiform, slender, and smooth ; 

 the second and third pairs being didactyle, the fourth 

 and fifth monodactyle. The abdomen is long, each seg- 

 ment being beautifully sculptured ; the raised portions 

 smooth and polished, the depressions covered with a 

 short but dense pubescence. The epimeral portion of 



