440 FLOKENCE BUCHANAN. 



cirri rather shorter, those of the 2nd pair of parapodia being 

 larger than the rest. 



Pharynx and jaws not present in the specimen. 



Colour (in spirit) : of the eye-stalks dark blue-black ; of the 

 prostomium itself dark, but not quite so dark ; of the dorsal 

 and ventral surface of the body dark brownish, the parapodia 

 somewhat lighter, and the ventral ridge below the nerve-cord 

 also of a lighter colour; '^branchise'^ darker in colour than the 

 rest of the parapodium. 



Length of single specimen, consisting of ninety-two seg- 

 ments, but incomplete posteriorly, 32"5 cm. ; breadth, including 

 parapodia, 4'2 cm. ; of the dorsal surface of the body alone 

 2 cm. 



Hab. — Single specimen, obtained off the mouth of the river 

 Congo, about thirty-five miles from land, at a depth of from 

 forty-three to fifty-seven fathoms, from a bottom of mud and 

 weed. The colour of the water where it was taken was of a 

 uniform reddish orange. 



It is probably tube-forming, although no tube was found with 

 it. The various points are illustrated in the figures (1 — 8). 



With regard to the other fourteen species of the sub-family 

 (or rather thirteen, as the Acoetes lupina of Stimpson is 

 probably the same as A. Pleei), reference to the list given 

 on p. 435 will show that six genera have been formed for them. 

 Grube (8) has long ago disposed of one of these by placing 

 Acoetes Pleei in the genus Polyodontes. Beddard (3) 

 has recently proposed to throw the genera Eupompe and 

 Pan th a lis into one. I agree with him, but would go further, 

 and place provisionally both these genera in one genus with 

 Polyodontes, bearing in mind that closer acquaintance with 

 the different species and the discovery of new ones will pro- 

 bably lead hereafter to a new subdivision into genera, but 

 probably not — it seems to me, at least — coinciding with what 

 we now know as the genera Polyodontes, Eupompe, and Pan- 

 thalis. The number of genera needed in any group of animals 

 depends entirely on which different forms and how many of 

 them happen to be known at the time. When only three 



