250 CEYLON PEARL OYSTER REPORT. 



Lower antenna 1 about as long as the body. 



First and 2nd gnathopods normal ; hind margins very setose. Side-plates wider 

 below, with a strong curved tooth at the posterior angle. 



First and 2nd peraeopods : dactylus nearly twice as long as the 2 preceding 

 joints. Side-plates of the 2nd with the upper posterior angle hollowed, leaving an 

 acute angle below (fig. 1 1. pp. 2 ). 



Third peraeopods : 1st joint convex in front, with a rounded expansion behind ; a 

 submarginal row of 5 short spines on the 4th joint; 5th joint widening distally, with 

 3 short submarginal spines on the proximal half. 



Fourth peraeopods : 1st joint subquadrate. 



Fifth peraeopods: lower margin of the 1st joint slightly concave, reaching to the 

 end of the 2nd joint, with many long setae ; 2nd joint subquadrate ; 3rd joint shorter 

 than 4th, front angle produced with 2 or 3 spines, hind angle slightly produced ; 

 4th joint rather shorter than 2nd, front angle much produced, bind angle not at all ; 

 5th joint oval, widest near the base, about one-fourth longer than the 2nd, a few 

 short spines at the distal end. Dactylus as long as the 5th joint, tapering gradually 

 to a long crooked point (fig. 11. pp. 5 ). 



First uropods reaching the end of the peduncle of the 2nd ; rami slender, curved, 

 unarmed, about as long as the peduncle. Second reaching beyond the end of the 

 peduncle of the 3rd, rami wider than those of the 1st pair, straight, subequal ; a few 

 short spines on their inner margins, the outer with a long serrate spine near the end 

 of the inner margin. 



Third uropods: the peduncle narrowed abruptly in the middle, where there is a 

 curved spine and a setule ; outer ramus narrower and a little shorter than the inner, 

 with a long simple spine near the tip and a few plumose setae on the distal half of the 

 inner margin ; inner ramus with the end slightly curved outwards, 3 slender spines 

 near the end of the inner margin and 2 unequal setae on the rounded point ; both 

 rami are widest at about one-fourth their length from the peduncle (fig. 11. ur.). 



Telson divided to the base, without spines ; a few setules on a median fold of each 

 division ; this is sometimes notched at the end with a setule in the notch (fig. 11. t. ). 



Length, 10 millims. 



Distinguishable by the prominences on the urosome segments. 



Ampelisca scabripes," n. sp. Plate II., figs. 12. 



Areas (A), (C), (II) : apparently not abundant. 



Head as long as the first 2 segments, rounded below the upper antennae. Eyes 

 distant, with a crimson spot behind each, and a smaller one behind the uppermost 

 (tig. 12. c). 



Hind margin of the 3rd pleon segment convex, the angle upturned but rounded 

 (fig. 12. pi. 3 )! 



* From the scabious 4th joint of the 3rd and 4th perseopods. 



