952 



CRUSTACEA. 



and fourth joints long, subequal ; flagellum but little longer than 

 third joint, seven to ten-jointed. First pair of feet small, hand sub- 

 ovate; second pair stout, hand nearly trapezoidal, broad and oblong, 

 a little broadest at apex, and truncate a little obliquely, below setu- 

 lose, palm not at all excavate, finger half as long as hand. Three 

 posterior pairs subequal, the last little the longest, tufts of setae 

 numerous, short. Posterior stylets quite long. 



Plate 65, fig. 6 a, animal, enlarged ; b, part of flagellum of superior 

 antennae. 



Sooloo Sea; from shores of a small island off the harbour of Soung; 

 collected, February 5, 1842. 



Length, three lines. This species is peculiar in its very stout first 

 basal joint of the superior antennae, the long appendicular branch, and 

 the long posterior stylets, which extend back much beyond the prece- 

 ding. The setae on the flagellum of the superior antennae are about 

 as long as the joints. The anterior hands are about as long as the 

 joint next preceding (carpus), and both have short, stiff hairs on the 

 margins. The finger of the hand of second pair folds against the 

 terminal margin, and does not project below it. The third and fourth 

 pairs of legs are slender and subequal. The basal joint in the last 

 three pairs is narrow oblong, and serrulate behind. The first and 

 second pairs of stylets extend nearly to the same distance back, the 

 third pair much farther. 



In a profile view, a few scattered short hairs are seen over the back 

 of the animal. 



Gammarus /unicornis, Dana, Proc. Amer. Acad. Sci., ii. 211. 



Gammarus TENELLUS. 



Maris : — Gracilis, epimeris totis angustis. Oculi rotundati, parvuli. 

 Antennas lrnce dirnidii corporis longitudine, articulo primo non crasso, 

 secundo valde longiore, flagello parce longiore quam basis, setis perbre- 

 vibus; appendice fere dimidio breviore. Antennas 2dce tenuissimas, 

 breves, basi paulo breviore quam basis Imarum, flagello non longiore 

 quam articulus precedens. Pedes lmi parvuli, rnanu subovatd, dorso 



