I9 X 5-] Fauna of the Chilka Lake ; Crustacea Decapod a. 253 



The eyes are subquadrilateral in dorsal view with their inner distal angles pro- 

 duced to a bluntly pointed process and their anterior margins oblique and concave. 

 The inner margins are almost contiguous ; they are straight and parallel with the 

 outer margins. In the middle of the distal half there is a small round patch of black 

 retinal pigment. The apices of the eyes reach a little beyond the articulation 

 between the first and second antennular segments. The latter segment is stout, 

 scarcely twice as long as broad. The third segment is more slender, but compared 

 with some other species of the genus is comparatively short, less than one and a half 

 times the length of the second. The distal extremity of the third segment reaches 

 about to the middle of the terminal segment of the antennal peduncle. The anten- 

 nal flagellum is apparently incomplete in the specimen described; it is, however, 

 considerably longer than the subequal flagella of the antennules and is fully one and 

 a half times the length of its peduncle. 



The form of the outer maxillipede is shown in text-fig 2 iß. The ischium, 

 merus and propodus are extremely broad and on the inner face of the first of these 

 segments there is a longitudinal row of small granules commencing close to the 

 articulation with the basis. 



The first legs are very unequal. In the larger— the right in the specimen described 

 (pi. xiii, figs. 2,3) —the ischium is slender, but considerably expanded towards its distal 

 end. The inferior edge is finely but irregularly tuberculate, the tubercles sometimes 

 taking the form of small spinules ; on the outer surface in the proximal two-thirds there 

 is a sharply defined crenulate carina. Between this carina and the lower margin, the 

 surface is covered with close-set granules that extend nearly to the ischio-meral joint. 

 The merus is a trifle longer than the ischium and is rather more than two and a third 

 times as long as broad. In form it is trigonal, the outer surface being traversed 

 longitudinally by a conspicuous ridge, smooth distally, but crenulate at its proximal 

 end. The upper border is finely crenulate in its basal half; otherwise the surface 

 above the median ridge is quite smooth. Below it the surface is covered with tuber- 

 cles, which are larger towards the proximal end, and near the inferior margin there is 

 an oblique granular crest. The inferior margin is granular and setose and near the 

 ischial articulation is produced to a large acute tooth. On its inner face the merus 

 bears two conspicuous grooves that run close to and parallel with, the upper and 

 lower borders; the surface is granular at the proximal end, otherwise quite smooth. 



The carpus of the same limb is one- third broader than long ; its length is about 

 two-thirds that of the merus. The outer surface is smooth and evenly convex. The 

 posterior margin below the mero-carpal joint is setose and a little uneven and the 

 infero-distal angle bears a few spinules at its apex. On the inner surface the upper 

 limit of the excavation into which the merus fits is defined by a strongly granular 

 ridge and there are also scattered tubercles near the sharp crest that forms the upper 

 margin and near the inferior angle. The distal margin, next the propodus, is finely 

 crenulate internally ; externally it is smooth. 



The palm of the chela, measured along its upper margin, is one quarter longer 

 than the carpus and is equal in breadth with that segment ; it is rather more than 



