in tlie Museum of the Smithsonian Institution. 131 



and armed with eight small and somewhat distant teeth. The anten- 

 nae and antennulse are of equal length, and about two-thirds as long as 

 the body. The inner flagelluni of the antennulse is one-half as long 

 as the outer one, of which the thick part is short and united to the 

 thin part for but a short distance at the base. The antennal scale is 

 broad, and the lobe of the inner extremity projects strongly forward. 

 The outer maxillipeds are very slender, and reach a little beyond the 

 extremity of the peduncle of the antennfe. Feet very slender ; almost 

 entirely naked, and unarmed ; in those of the second pair the cai'pus 

 reaches to the extremity of the rostrum ; hand very small, and less 

 than half as long as the carpus. Posterior feet so slender as to be 

 almost hair-like ; those of the last pair reach to the extremity of the 

 rostrum. Candal segment slender; outer caudal lamella much longer 

 than the inner one. 



The color in my (alcoholic) specimens is faded, but the antennal 

 scales, the lower margins of the abdominal segments, and the caudal 

 lamellje are still seen to be margined with blueish-white, and the 

 colors were probably much more brilliant than is usual in the grovip. 



The length is about an inch and a half. 



This species is distinguished by the great length of its re- 

 curved rostrum, and of its antennae and feet. 



It was found by Prof. Tlieodore Gill in fresh-water streams 

 near the sea, either in Barbados or Trinidad ; — he is uncertain 

 whicli. 



8icyonia laevig^ata, nov. sp. 



The body is small and I'ather slender, and moderately compressed. 

 The dorsal crest of the carapax is tridentate ; teeth small, acute, equi- 

 distant ; the posterior one sitviated nearly at the posterior third of 

 the length of the carapax. Lateral spine of carapax very slender. 

 Rostriim slender, pointing forward and upward at an angle of about 

 20° with the axis of the bodj^ ; it is twice as long as the eyes, and 

 reaches nearly to the extremity of the penult joint of the peduncle 

 of the antennulse ; it is armed above with one minute tooth over the 

 eyes, and one near the extremity ; its extremity is truncate and armed 

 with two or three spiniform teeth ; its lower margin is almost entire. 



