POLYCH^ETA. 295 



elongate conical. The tentacular acervi occur on the dorsum of the second setigerous 

 segment, i.e., the fifth body-segment, the first three segments being as usual achsetous. 

 In one specimen a small gill occurs on the third achsetous segment. Both dorsal and 

 ventral acicular setse are present in the 36th setigerous segment. Gill-filaments only 

 occur in the anterior region of two complete individuals. The gill-filaments and 

 tentacular filaments give the appearance of a dense tangle in front, the rest of the 

 body being bare. 



The species differs from C. dasylophius, Ma.renzeller, in the position of the 

 tentacular cirri, the distribution of the gill-filaments and the shape of the body. 



Heterocirrus typhlops, n. sp. Plate V., fig. 138. 



Locality : South-west Cheval Paar, Gulf of Manaar. 



A very small worm, total length 10 '5 millims., diameter less than half a millimetre. 

 Capillary non-limbate setae in both fascicles ; dorsal and ventral acicular setse 

 commence at the first setigerous segment ; they resemble those of Cirratulus ; the 

 ventral acicular setae are two in number, more curved and thicker than the dorsal. 

 The disposition of such cirriform appendages as remain is shown on Plate V., fig. 138. 



Family : AMPHICTENIDiE. 

 Pectinaria panava, n. sp. Plate V., fig. 137. 



Locality : Ceylon Seas. 



The specific name is the vernacular word for comb, referring to the comb of 

 palese. Nuchal disc subcircular, carrying a transverse series of twenty palese, divided 

 by an interval into two linear groups of ten each ; the palese terminate in curved 

 setiform apical processes. At each ventro-lateral angle of the disc, at the outer ends 

 of the paleal series, there is a tentacular cirrus ; a similar pair of cirri occurs on the 

 second segment. In front of and below the paleal crown there is a wide semilunar 

 membrane carrying not less than 32 lacinise frontales. Below the frontal membrane 

 are the grooved tentacles surrounding the mouth. Third and fourth segments 

 branchiferous ; ventral portions of 3rd, 4th, 5th and 6th segments elevated, the 

 crests traversed by transverse muscles ; the crest of the 4th segment is produced on 

 each side as a blunt lateral lobe below the gill ; on the posterior surface of the lobe 

 there is a pinhole aperture. Seventeen capillary fascicles commencing from the 5th 

 segment ; uncinigerous tori from the 8th ; uncini with about eight teeth, reduced 

 towards the base (Plate V., fig. 137). Scapha acetabuliform, with terminal supra-anal 

 semilunar valve and two rows of dorsal palese at the base, 7 palese on each side. 



Tli is species is chiefly characterised by the number of palese, which however is 

 likely to vary, and by the large number of the lacinise frontales, which are filiform 

 processes along the edge of the frontal membrane. 



