Pli Ijllopoda of Audralla. 237 



the first two (genital segments) are partly coalescent and bear on 

 the ventral surface the two penes and ovisac of the respective 

 sex, the remaining seven gradually become narrower landwards. 

 The cephalon is divided into an anterior part and a so-called 

 cervical segment ; the anterior part is broadest posteriorly, the 

 stalked eyes are lai'ge and prominent, the ocellus, or simple eye, 

 minute, the antennules long and filiform, and extending in the 

 males to about the end of the basal joint of the claspers. In the 

 females they are relatively slightly shorter. 



The labrum, or anterior lip, is large and curves below, where 

 it covers the lower part of the powerful mandibles. Viewed from 

 below it is of the visual triangular shape, with the apex pointed 

 hindwards. 



The branchial limbs are borne by the eleven segments of the 

 trunk, anrl gradually increase in size towards the middle, then 

 gradually become smaller posteriorly. They are of normal form 

 and size, the covering plates very large and their outer margins 

 seirated, the gills much smaller and of ovoid shape, the exopodite 

 broadly ovoidal, with outer margin almost straight, inner strongly 

 and evenly curved from the proximal to the distal extremity. 

 The distal lobe of endopodite (6th endite) is short and broad in 

 average sized specimens (Fig. 7), in larger ones longer and pro- 

 portionately narrower. The inner side is never produced beyond 

 the level of the endites above, and the distal margin is distinctly 

 excavated, most noticeable in the limbs of the middle area; inner 

 margin more or less strongly curved (least so in matured forms), 

 and evenly merged into the distal margin. There is no funda- 

 mental difference in the two sexes. 



The terminal segment is short, and from it the caudal rami 

 extend posteriorly and somewhat divergent, and are rather longer 

 in the males than females ; they are dorso-ventrally fi.attened, and 

 taper gradually from the base to the narrowly rounded extremity, 

 the lateral margins and end being fringed with long feathered 

 setse. 



In mature females the ovisac is pear-shaped, with the apex 

 elongated, but is subject to considerable dilFerences of size and, 

 ill a lesser degree, shape. I have found ripe eggs in forms where 

 its distal extremity only extended to slightly below the end of 

 the third segment of the metasome (Fig. 1), and others, but 



