POLYCJLETA -BENHAM. 6? 



Family AMPHARETID^. 

 Genus PHYLLOCOMUS Grube.* 

 PHYLLOCOMUS DIBRANCHIATA sp. nav. 

 (Plate 10, figs. 107-123.) 



A worm which was dredged from a depth of 157 fathoms, seems to form the 

 type of a new species of this rare genus. 



It is distinctly differentiated into thorax and abdomen, the former bearing both 

 notopodial chsetae and rncinigeious neuiopods, the latter presenting only the 

 neuropods, wH?h project laterally like wings o: oars. 



The specimen (fig. 107) is very well preserved, and appears to be strongly 

 contracted anteriorly ; it is a pale yellowish colour, while the parapods and glands are 

 pale brownish and the ventral surface of the abdomen rather darker. 



It is fortunately complete, though the hinder end appears to be regenerated, as 

 no uncini can be detected on the last ten segments. 



Its total length is 45 mm., with a width of 11 mm. anteriorly and a height of 

 8 mm. The body tapers backwards slowly, so that at the commencement of the 

 abdomen it measures 6 mm. in width. 



The worm contains 60 segments, with head and anal funnel, which is surrounded 

 by a number of short cirri (fig. 115). There are 15 notopods with long pale yellow 

 chaetse; 14 of these thoracic segments are glandular across the whole ventral surface, 

 though distinct gland shields are not evident. The anterior glands spread from the 

 neuropods of one side to those of the other, which are here separated by a space of 

 8 mm. The last three or four are traversed by a definite furrow in the middle line. 

 There are indications of two additional glands behind these. 



The head (figs. 108, 109) is very obliquely truncated, so that its anterior face is 

 nearly vertical; the prostomium has the form of a sub-circular plate sloping down wards 

 from the dorsal surface of the body, nearly at right angles to the body axis; the lower 

 extremity of this plate is free, and its edge is thin. This prostomial plate is of firm 

 consistency, almost chitinoid; it is tinted in the middle with reddish brown pigment, 

 is slightly convex from side to side in its middle, and slightly concave from its front 

 backwards, so that its free rounded edge projects horizontally. 



On each side, between the prostomial plate and the curved peristomial ridge, is 

 a narrow elongated depression from which a slight papilliform elevation rises. Grube 

 suggests that this is a secretory organ; perhaps, however, it represents the ciliated 



uses the 

 me that 

 this rare word. 



83892 N 



