POLYCH^TA—BENHAM. 9/ 



Family A:\rPHARETIDyE. 



Genus Phyllocomus Gruhe* 



PhyllocomUvS dibranchiata sp. )tov. 



(Plate 10, figs. 107-123.) 



A worm whicli 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 fornier bearing both 

 notopodial cha?ta3 and incinigei ous neuiopods, the latter presenting only the 

 neufopods, whi di project la*:erally like wings or oars. 



The specimen (fig. 107) is yery 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 al)domen rather darker. 



It is fortunately com])lete, 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 nreasures 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 

 chsetae; 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 

 neurojiods 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 Ijy 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 jJi'ostomium has the form of a sub-circular plate sloping downwards 

 from the dorsal surface of the l)ody, 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 browai 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 dejaression from whicli a slight papilliform elevation rises. Grube 

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



*" Phyllocomus " looks like a masculine word and appears to refer to the " foliaceous " form of the gill ; but Grube 

 uses the feminine "crocea" for the species. I therefore consulted my Classical colleague, Professor Adams, who informs 

 me that there is a rare Greek word " komos " meaning a " bundle or sheaf," which is feminine : presumably Grube used 

 this rare word. 



•83892— N 



