STALK-EYED CRUSTACEA 6r 



gastric region is not much developed, but the branchial 

 regions are so, and have lateral spines. The rostrum is 

 well developed, sometimes rather small, emarginate, or 

 bifid at the apex, and so terminating in two teeth or spines. 

 The eyes small, very short. The orbits directed very 

 obliquely forwards and outwards. Their external angle 

 is formed by a large compressed tooth, which is separated 

 from the sides of the cavity by two fissures, the upper one 

 very narrow, the one below more or less open. Praeocular 

 spine usually distinct. 



The basal joint of the external antennse is short, and 

 is armed with a spine at the antero-external angle, behind 

 which, on the exterior margin, is usually another tooth ; 

 the second articulation is thick, short, cylindrical, and 

 inserted upon the sides of the rostrum at almost an equal 

 distance from the orbit and antennulary fossae ; the third 

 joint is a little smaller than the second, and the fourth is 

 very frail and very short. The flagellum is not concealed 

 by the rostrum. The epistome is very small, and all the 

 antennary region is a fraction of the size of the buccal 

 cavity. 



The legs of the first pair are well developed, and are 

 always about the same size as those of the second pair, 

 and in general not as long, even in the male; the hand 

 is almost cylindrical, and slightly swollen; the fingers are 

 minutely and evenly denticulated on the inner margins, 

 where they touch in almost their entire length when 

 closed. The walking legs are well developed, sometimes 

 elongated, with the joints subcylindrical, unarmed ; the 

 last joint nearly straight. 



The abdomen is composed of seven segments in both 

 sexes. 



Range. — Atlantic and Pacific, on both coasts of 

 America. 



