1904.] 



POLYCHyETA OF THE MALDIVE ARCniPELAGO. 



281 



dorsally, but the remainder, like all those of the region C, -.ive 

 very delicate dorsally, black, and annulated by the rings of muscle 

 which surround the body at each pair of parapodia, as mentioned 

 above. 



This region consists of 24 segments. Its parapodia are pro- 

 portionally much larger than are those of the former species. 

 The gills are of the usual structure, the lower flap being large 

 and continuous with the ventral pai't of the neuropodial torus 

 (PL XIX. fig. 5, gill, v.neur.). The dorsal ramus of the noto- 

 podium contains six slender setse, with delicate club-shaped ends 

 which do not project. 



In the first segment of this region the gill-flap is not developed 

 nor is the neuropodial torus divided. In the remaining segments, 

 however, the doi-sal part is small and placed in front of and below 

 the upper edge of the ventral part (PI. XIX. figs. 5 & 6). The 

 uncini, as in the region C, are ti-iangular, with veiy minu.te teeth, 

 which are, however, distinctly visible under a -^-inch objective 

 (PI. XIX. fig. 4 d). 



The notopodia of the i-egion C are small, projecting vertically 

 from the dorsal surface. Each is a clavate papilla containing one 

 striated seta, the leaf-like head of which half projects (PI. XIX. 

 fig. 7). The figure is of an optical section, showing the prolon- 

 gation of the ccelom i-ound the seta, which is covered by the 

 delicate ccelomic epithelium. 



As in the case of the preceding species, its size and the fact 

 that but one specimen was collected indicate that it inhabits a 

 straight tube occurring singly. 



Locality. Dredged off Minikoi Atoll, the Maldive Archipelago. 



Genus Hyalincecia. 



Hyalincecia camiguina Grube. (Plate XIX. figs. 8-11.) 



This species, first described by Grube fi-om Samper's Philippine 

 collections, was dredged from the following localities in the 

 Maldives. 



NortliMale Atoll ... 37 fatli. 



■ ■■ 20 „ 



■ ■• 25 „ 

 S. Nilaudu 30 „ 



36 „ 



Kolumailulu 35 „ 



Mahlos 20 „ 



Felidu 25 „ 



Fadiffolu 22 „ 



Miladumadulu 28 „ 



Sand, sliell, and rubble. 2 large specimens. 



Broken shells. 



Dead coral and sponge. 



Hard. 



Hard sand. 



Weed and sand. 



Sand and rubble. 



Coral rubble. 



Weed, sand, and stones. 



2 smaller. 



5 large. 



Numerous, small. 



2 large, 2 small. 



1 large. 



1 large. 



5 large. 



1 large and 1 small. 



The smallest tubes measui'e 3 cm. x 0'15 cm., the largest 

 4"5 cm. X 0"25 cm. They are slightly curved and a little thinner 



