258 Memoirs of the Indian Museum. [Voi,. V, 



lateral tooth on each side is long and sharp and, when seen from above, is separated 

 from the margin of the rostrum proper by a V-shaped incision which is continued 

 backwards in the form of a deep furrow almost to the cervical groove. External to 

 this furrow and parallel with it is a strong ridge which extends to the tip of the 

 lateral tooth. These ridges and the upper surface of the rostrum are covered with 

 fine hair, but are otherwise smooth and without trace of granules or tubercles. 



The carapace behind the deeply cut cervical groove is smooth and polished. On 

 the frontal margin behind the eye there is a small and inconspicuous tubercle, some- 

 times almost obsolete, and where the cervical groove is cut by the linea thalassinica 

 there is a stout hepatic spine. 



The antennular peduncle extends but little beyond the rostrum. The third 

 segment is very slender and fully three times the length of the second (text-fig. 22a); 

 the flagella are subequal, about three-quarter the length of the peduncle. The 

 antennal peduncle is composed of only four distinct segments (text-fig. 22b). At the 

 distal end of the second segment there is a large ventral spine and, not infrequently, 

 a small dorsal spinule. Superiorly, between the second and third segments, is a 

 small articulated piece consisting of a single tooth with a broad base ; this is appa- 

 rently a rudiment of the antennal scale and not a vestige of the suppressed segment. 

 The third segment bears one, less commonly two teeth on its ventral margin near 

 the proximal end. 



On the third maxillipedes (text-fig. 22c) there is a rudimentary epipod. 

 The first legs are subchelate in the male (text-fig. 22^), monodactylous in the 

 female (text-fig. 22ß). In both sexes they reach beyond the rostrum by the whole of 

 the last three segments. There is a spinule on the lower margin of the ischium and 



a series of from 2 to 6 on the same edge of 



the mer us. The upper border of the latter 



segment is unarmed except for one (rarely 



two) subterminal spines. The carpus is much 



widened distally and is little more than half 



the length of the merus. It bears three or 



four spines. Three of these are placed at the 



Fig. 23.— Upogebia (Upogebia) heterocheir, distal end, one above, one below and one on 



S P- nov - the inner side; the fourth, which is rarely 



Last two segments of the first peraeopod of a absent l , is smaller than the others and is situ- 



large male ; from a cast skm. ' 



ated on the upper margin at about the middle 

 of its length. The propodus is longer than the merus and, on its upper edge, bears 

 from two to four spines. In adult males it is from two and a half to three times as 

 long as broad, whereas in females, in which the whole limb is more slender, it is fully 

 four times as long as broad. In the latter sex there is only a comparatively small 

 subterminal spine on the under margin ; in the male it is much enlarged forming, with 

 the dactylus, a subchela. This tooth or fixed finger of the male is less than half the 



1 It is absent in text-fig. 22d. 



