296 CEYLON PEAEL OYSTEE REPORT. 



Fourth and 5th perseopods like the 3rd, except the 1st joint, which is wider and 

 rounded behind. 



The outer rami of the 1st and 2nd uropods are shorter than the inner and are 

 terminated by a long spine, as also the inner ramus of the 2nd pair ; the inner ramus 

 of the 1st pair lias 3 shorter and unequal spines and the inner margin finely pectinate 

 and spinulose (fig. 51. ur. ). 



The 3rd uropods are uni-ramous, oval, acuminate, with a setule at the tip, about 

 two-thirds covered by the telson (fig. 51. up.* 8 ). 



The telson seen in profile is triangular, with 2 spines on the summit and the margin 

 of the extended base upturned (fig. 51. t.). 



Length of female with ova, 3'5 millims., but the females appear to become sexually 

 mature very young in this genus, as much smaller females are full of ova. 



In 1888, Ohevreux and De Guerne referred Haswell's genus Dexiocerella to 

 Cyrtophium, Dana, and as the specific name Iceve was preoccupied by C. lave, Heller, 

 they re-named Haswell's species C. haswelli. As, however, the species belongs to 

 Platophium, I have reverted to Haswell's name, Heller's species having no 

 antennular appendage. 



It is possible that this species is identical with Cyrtophium orientale, Dana, in 

 which, however, no antennular appendage is figured or described. 



Platophium synaptochhy* n. sp. Plate VIII., figs. 52. 



Galle Harbour and Bay, very abundant. Kondatchi Paar, Periya Paar Kerrai, 

 East Cheval Paar. All taken from May to November, 1902. 



Male: The first 4 segments of the mesosome are subequal, the 5th rather shorter, 

 the 6th longer; the 7th the longest; all, as well as the pleon segments, have a 

 transverse dorsal depression, and are elevated behind, but not carinate or produced 

 behind. Urus with 3 distinct segments. Head longer than the 1st segment ; 

 ocular lobe subangular. Eye large, round, dark red. 



Upper antennas reaching to one-third of the last joint of the peduncle of the lower ; 

 the 1st joint twice as thick and more than half as long as the 2nd, which is about 

 one-fourth longer than the 3rd. Flagellum as long as the 3rd joint, 5-jointed, the 

 1st joint as long as the remaining 4. Appendage 1-jointed, nearly half as long as 

 the 1st joint of the flagellum ; the whole rather sparsely clothed below with long, 

 simple setae. 



Lower antennas as long as the mesosome ; the 1st joint less than half as long as the 

 2nd, which is much shorter than the 3rd. Flagellum shorter than the 2nd joint, 

 4- jointed, the 1st longer than the remaining 3 ; the whole sparsely furnished with 

 short setae. 



* From o-waimi), to join, and \eip, hand, in allusion to the coalescence of the hand and wrist in the 

 2nd guathopods of the male. 



