STRUCTURE OF UROCILETA AND DIOHOGASTER. 251 
Allurus, furthermore, resembles certain of the Limicolous 
genera in the large size of its ova, and in the fact that the 
female reproductive pores are behind the male. I have not 
any evidence that Urochaeta can, like Allurus, lead an 
aquatic life ; but the resemblance which it bears to the 
“ Limicolae ” is shown in the possession of bifurcate setae as 
well as (perhaps) in the large size of its ova. Perrier dis- 
covered the former fact, and I have occasionally observed the 
same in specimens from British Guiana. 
II. Dichogaster Damonis, nov. gen. et sp. 
The present section contains some account of the anatomy 
of a species of Earthworm, which appears to be sufficiently 
unlike any other type at present known to justify the creation 
of a new genus for its reception. 
I have examined two specimens which I acquired from Mr. K.. 
Damon, of Weymouth. One of these was dissected, the other 
studied by means of transverse sections. 
The worms formed a part of the Godeffroy collection, 
recently purchased by Mr. Damon, and are labelled “ Hypo- 
gaeon.” This name has been applied to several very different 
species of Earthworms, and in Savigny’s original description 
is characterised by the possession of a single median seta in 
addition to the eight which are ordinarily found. In this 
character Hypogaeon differs from the present species. 
The species was collected in Fiji. 
§ External Characters. 
The setae are paired, and lie on the ventral side (fig. 8). 
The dorsal and lateral pair of setae are separated from each 
other by a rather greater interval than that which separates 
the ventralmost pairs of setae. The clitellum extends from 
segments 13 — 20 inclusive. It is not so markedly developed 
on the ventral as on the dorsal side ; hence the number of 
segments of which it is composed can be more easily reckoned 
