1114 



CRUSTACEA. 



finely pectinate on the apical half, the following of the same length, 

 the following four short. Branches of the posterior antennae nearly 

 equal. Right leg of the posterior pair of feet quite stout, rounded 

 at apex, lateral appendage very stout falciform, obtuse. 



Plate 78, Hg. 2 a, animal, enlarged ; b, right posterior thoracic foot. 

 Fig. 3 a, probably female of the same ; b, extremity of anterior an- 

 tennae. 



Atlantic, latitude 11° south, longitude 14° west, May 7, 1842; lati- 

 tude 4i° south, longitude 25° west, May 13, 1842; May 9, latitude 

 8J° south, longitude 15° west; May 16, latitude 1° south, longitude 

 30° west ; also, China Sea, three hundred miles northeast of Singa- 

 pore, February 17, 1842. 



Length, one-twelfth of an inch. Colour, smoky, with black bands 

 about the cephalothorax ; the extremities of the antennae and some of 

 the natatory legs also black. This species resembles the omata. But 

 the right leg of the posterior pair of the male is very different; the 

 right male antenna differs in the joints either side of the geniculating 

 articulation ; the branches of the posterior antennae are nearly equal. 

 The abdomen is five-jointed; the first segment has a sharp spinous 

 process on the right side. 



The figure of the female is drawn from a specimen collected in the 

 China Sea, with which the Atlantic specimens appeared to be iden- 

 tical. This specimen has also the following characters: — Tips of 

 posterior angles of cephalothorax, bent outward a little (they are 

 rather inflexed in the other figure) . Posterior joints of cephalothorax 

 four in number. Coloured nearly as the above. 



Figure 4 a, Plate 78, represents a male specimen, from the Straits 

 of Banca, east of Sumatra (collected, March 1, 1842), which may pos- 

 sibly belong to the same species with the last, and both may be of 

 different species from the specimen first described above. It is rather 

 slender, the abdomen very slender, five-jointed, segments without any 

 lateral process ; but first segment a little enlarged on the right side. An- 

 tennae about as long as body, not thrown as far forward as in the female 

 above, with second joint shorter, and not having so large a curvature 

 at base. Apical joint (fig. 4 b) not as long as the two preceding. 



