POLYCH^ETA. 297 



wider spatulate portion, disposed in a single series ; in both fascicles the spatulate 

 setae are accompanied by more slender limbate setae ; dorsally these segments carry 

 stout cirriform branchiae. Next follow the uncinigerous segments, as many as 50 in 

 number, after which the recurved achsetous caudal extremity terminates the body. 



The first 20 to 30 uncinigerous segments carry dorsal branchiae ; all carry ventral 

 fascicles of fine capillary seta?, and the first three are provided with ventral ligules 

 adjoining the capillary fascicles ; the capillary setae carry projecting laciniate scales 

 or minute thecae, overlapping like the cups of a Sertularian Hydroid. Adjoining the 

 mouth, between the latter and the neuropodial cirri or ligules of the buccal segment, 

 there is a pair of fleshy labial processes, which Mr. Watson identifies as tube-building 

 organs (Plate VIII., fig. 2).* 



It is possible that the Ceylon form may be varietally distinct from the Mozambique 

 type, and should be known as P. pennata, var. bicomis. 



Family: TEREBELLID^E. 

 Leprea inversa, n. sp. Plate VI, figs. 141 and 142 ; Plate VII., fig. 197. 



Station V., off Chilaw, Gulf of Manaar; 11 fathoms. One specimen. 



The body-length, exclusive of tentacular cirri, is from 30 to 40 millims. ; width 

 in front 2 '5 millims. The segments are numerous and the body much contorted. 

 The anus is surrounded by a funnel-shaped pygidium. The branchiae are inserted 

 without reference to particular segments, the third gill occurring high up on the 

 dorsal surface over the third or fourth setigerous lobe, the second over the first 

 setiger and the first gill in front. Between the first and second gill there is a 

 papilla. The first gill occupies the most ventral position and is the smallest in size, 

 not more than one-third of the bulk of the second gill, the latter having about one- 

 half to two-thirds the bulk of the third. There are eight ventral thoracic scutes 

 behind the tumid labium ; the first shield following after the labium is deeply 

 grooved transversely; the scutes end sharply in the region of the 8th and 9th 

 uncinigerous tori. The uncinigerous tori and the capillary fascicles are continued to 

 the posterior extremity of the body; from the 7th torus (11th segment) backwards 

 the uncini are biserially disposed. The tentacular cirri are not deciduous ; no eyes 

 were observed. The capillary setae of the anterior segments are very narrowly 

 limbate, with a slight twist towards the apex, but cpiite simple ; those from the 

 middle and posterior segments are geniculate (Plate VI., figs. 141 and 142). 



In the anterior region, behind the ventral scutes, the median ventral tract is 

 depressed between the tori. In the posterior abdominal segments the uncini 

 (Plate VII., fig. 197) are still biserial. The proportions of the branchiae, the differ- 

 ence between the anterior and posterior capillary setae and the number of ventral 



* A note upon the nature of the structures which, in the Sabellariidae, surround the mouth, appeared 

 in the 'Journal of the Marine Biological Association' (Plymouth), New Series, vol. vii. (1904), p. 301. 



2 Q 



