OUMACEA. 163 



to the slender abdomen. The first leg-bearing- somite is not distinct, though a rather 

 faint line which marks off a narrow, diamond-shaped area from the hinder part of 

 the carapace above may (as Zimmer has suggested in K. hilgendorfi) represent its 

 line of fusion with the carapace. The second somite also appears to be firmly united 

 to the carapace. The third and fourth somites are reduced above to narrow transverse 

 bars, connected with each other by wide spaces of articular membrane, so that tins 

 region of the body is very mobile and is usually strongly flexed dorsally, the dorsal 

 portion of the third somite being quite concealed beneath the second. 



The abdomen is very slender, longer by one-fifth than the cephalothoracic region. 

 The somites, which are sub-cylindrical, with a slight median dorsal keel, diminish a 

 little in width, so that the fifth, which is the longest, is also the narrowest, being 

 nearly four times as long as broad. The last somite is a little depressed and 

 broadened posteriorly. In the lateral articulations of the somites the anterior 

 articular process of each is met by and overlaps a single process from the somite in 

 front, instead of engaging in a notch as in most species of Cijclaspis. 



The antennules (fig. 7) have the basal segment large and of peculiar form. Its distal 

 half is bent at an angle to the proximal part and is flattened and triangular in form, 

 very broad at the base, and narrowing distally to the articulation of the second segment. 

 In the natural position of the parts this triangular portion appears to be firmly 

 fixed in a notch in the free edge of the carapace, corresponding, no doubt, to the 

 "autennal notch" in more normal Cumacea, but in the present case, owing to the 

 flattening of the carapace, carried round to the under surface and quite invisible from 

 the side or from above. The second and third segments of the antennular peduncle 

 are slender, the* third half as long again as the second. The external flagellum is 

 about half the length of the last peduncular segment and is composed of two sub- 

 equal segments. The internal flagellum is quite rudimentary and exceedingly 

 minute. 



The antenna (fig. 7) is a simple rounded nodule bearing two plumose setse. No 

 trace could be discovered of the narrow terminal segment generally present in allied 

 genera. 



The mandibles (fig. 10) are of the normal type, and carry a row of about 

 13 spines. 

 ' The lower lip (fig. 11) has broadly rounded lobes, clothed with fine setse. 



The maxilluke (fig. 12) have a slender palp longer by one-half than the distance 

 between its base and the tip of the distal lobe, and carrying two apical setae. 



The maxilla3 are of normal structure. 



The first maxillipeds (fig. 13) have the basis very broad and shorter than the rest 

 of the limb. The branchial apparatus is remarkably well developed. Its j)osterior 

 division (epipod) is produced forwards as a rounded lobe which reaches as far as the 

 end of the basis. The branchial lobules are broad, lamellar, and about 22 in number. 

 A reflexed anterior lobule could not be discovered. In the anterior division (exopod 



Y 2 



