g^g CRUSTACEA. 



earth, at fifteen hundred feet elevation, on the island of Tahiti, 

 several miles from the sea. 



Length, one-fourth to one-third of an inch. Colour, bluish to bluish 

 green. The epimerals of the fifth segment may be too narrow in the 

 figure : the loss of the specimen prevents our verifying this point. 

 The superior antennae are nearly three-fourths as long as the base of 

 the inferior. The abdominal natatories are very small. The stylets 

 of the first and second pairs are quite long and slender ; those of the 

 third pair are very short. 



These animals hop off with agility, when exposed by turning over 

 the leaves that cover them, until they reach a spot where they are 

 more or less concealed, and there they lie quiet till disturbed again. 



Orckestia rectimana, Dana, Proo. Ainer. Acad. Sci., Boston, ii. 203. 



Orchestia dispar. 



Maris : — Epimerce mediocres, quintce 4:tis vix breviores. Antennce 2dce 

 vix dimidii corporis longitudine; flagello paulo longiore quam basis, 

 articulis vix oblongis, setis brevissimis semidiametrum articuli non supe- 

 rantibus. Antennce Imce dimidio basis secundarum longiores. Pedes 

 lmi parvuli, manu ad apicem latiore, oblique truncatd et excavatd. 

 Pedes 2di validly manu late subellipticd, oblique^ truncatd, palmd paulo 

 sinuosd, pubescents. Pedes 2>tii 4:tis parce longiores; 7mi Qtis paulo 

 breviores, articulis tertio quartoque incrassatis, late compressis, setis 

 perbrevibus, illis articuli bti sernidiametro articuli vix longioribus. 



Male : — Epimerals of moderate size, fifth but little shorter than fourth. 

 Inferior antennae scarcely half as long as body, last two joints of base 

 subequal, flagellum longer than base, joints hardly oblong, setae not 

 longer than half the diameter of the joints. Superior antennas 

 shorter than base of inferior. First pair of feet having the hand 

 quite small, broadest at apex and obliquely truncate, with the 

 apical margin excavate. Hand of second pair stout, broad, sub- 

 elliptical, obliquely subtruncate, palm of hand a little sinuous, 

 pubescent. Third pair of feet longer than fourth; seventh a little 

 shorter than sixth, and having the third and fourth joints stout, and 



