290 CEYLON PEARL OYSTER REPORT. 



is a crowded group of short blunt spines; the inner margin has a row of microscopic 

 cilise (fig. 50. up. 1 ). 



Second uropods of similar structure to the 1st, but shorter in extent. 



It is very difficult to determine which is the " inner" or the " outer" ramus, as, in 

 fact, the one lies immediately above the other in these 2 pairs. 



Third uropods : peduncle subequal to the inner ramus, which is rather longer than 

 the outer ; both are alike and simple, with obliquely truncate setose ends (fig. 50. up. 3 ). 



Telson as in Gammaropsis. 



Length of ovigerous female 4 millims. 



Probably a tubicolous species, from the structure of the last 3 pairs of legs. So far 

 it has only been obtained from the washings of pearl oysters. 



Amphithoe, Leach, 1813. 

 Amphithoe intermedia, n. sp. Plate VII., figs. 46. 



West Coast of Ceylon, from Colombo northwards. 



Head shorter than the first 2 segments. Ocular lobe slightly produced, subangular. 

 Eye round, red. 



Third pleon segment : lower and hind margins convex, angles rounded. 



Upper antennas : 1st joint stout, almost as long as the slender 2nd ; the 3rd barely 

 one-third of the 2nd; flagelluin slender, 30-jointed. 



Lower antennas : 1st joint very short, 2nd and 3rd subequal, but the 2nd the 

 wider : flagellv/m subequal to the last joint of the peduncle, 9-jointed. 



Mandibles normal, the palp scarcely as long as the mandible ; 1st joint about half 

 as long as the 2nd, which is subequal to the 3rd ; this widens distally and is obliquely 

 truncate, with 7 pectinate setas on the truncate part and 1 below (fig. 40. m.). 



First maxillae : inner plate with 3 seta; (fig. 46. mx. 1 ). 



Remaining mouth organs and maxillipeds normal. 



First gnathopods in the female as in A. rubricata (Mont.), the side-plates rather 

 wider below, with a few setae on the rounded posterior angle. In the male the whole 

 limb is more robust ; the hind margin of the wrist straight, crenate, setose, and 

 ending in an acute angle ; the hand scarcely as wide as the wrist, oblong ; the 

 dactylus strong and serrate (figs. 46. gn. 1 ? and cj). 



Second gnathopods in the female very like and but little larger than the 1st ; the 

 side-plates oblong, with setae as in the 1st ; the wrist is produced behind in a truncate 

 lobe which is densely setose; the hand is about half as long again as the wrist, the 

 palm, slightly ameer, defined by a spine, but rounded off into the hind margin, which 

 is rather the longer ; the whole hind margin setose. Dactylus reaching a little 

 beyond the palmar spine, serrate (fig. 46. gn.- ? ). 



In the male the side-plates are suborbicular, the diameter less than the length of 

 the 1st joint, which is subequal to the next two; the front margin of the wrist is 



