482 STALK-EYED CRUSTACEA 



of the peduncle, have a basal scale that is about two- 

 thirds the length of the carapace, and terminate in a long 

 flagellum. 



The external maxillipedes have only three joints ex- 

 posed, of which the terminal is the shortest and ends 

 in an obtuse point ; there is a rather slender external 

 appendage. 



The first pair of legs is slender. The second pair 

 resembles the first, but is longer and larger. The three 

 other pairs of legs resemble each other, and approach in 

 length that of the second pair; the terminal joint is 

 simple, the next joint (the sixth) long and cylindrical, 

 the next joint (the fifth) has the anterior distal angle 

 produced beyond the carpal articulation of the sixth 

 joint. 



The gills are attached to the body wall, to the 

 membrane between the body and the first joint of the 

 external maxillipede, and to the first joint of the internal 

 maxillipede. There are no branchial plates. 



Range. — America Rivers, Gulf weed, European Seas, 

 East Indies. 



I. Palaemon natator. 



Palceniou natator . . . H. Milne Edwards, Spence 



Bate. 



Leander erratiais . . . Desmarest. 



The rostrum is as long as the basal scale of the ex- 

 ternal antennae, narrow at the base, but very wide towards 

 the tip, having slightly the form of an arrowhead armed 

 with eleven or twelve teeth above and scarcely toothed 

 below. The legs of the second pair are of moderate 

 length, very thin at the base, but narrowing towards 

 their extremity ; hand oval ; fingers longer than the palm, 



