Crustacea. 243 



front. Two thoracic segments are readily distinguishable, and the 

 other three can at times be made out. 



Both pairs of antennae, the pereiopoda and the abdomen closely 

 resemble those of the adult male. 



In the younger individuals and larvae the cephalon is narrower, 

 and bears very large eyes upon lateral tubercles. The mouth organs, 

 which are at these stages of the normal number, are produced into 

 a more or less conical structure in front of the head. 



A fairly large number of specimens of this species were taken at 

 various times off Cape Adare, most of them coming from a depth of 

 twenty fathoms or thereabouts. In one case the tube was labelled : 

 " 20-24 fathoms. From the roots of seaweed." But all presented the 

 appearance of living in a similar habitat. They were dirty, and 

 as a general rule more or less covered with some growth, which con- 

 cealed some structural features and gave them a velvety appearance. 

 The specimens include well-developed males and females, as well as 

 larvae. 



SPHAEROMIDAE. 



Considering the great confusion that exists among the numerous 

 members of this family, it is with some hesitation that I put forward 

 two new species. The difficult problem is to assign to these species 

 the genus which might meet with general approval. Authors do not 

 appear to be agreed on the subject of generic distinctions, and on 

 that account I may have added to the existing confusion. Notwith- 

 standing the obvious differences in form I have placed both species 

 in the genus Cymodocea (Leach). The anatomical details do not 

 appear to me to warrant their separation. 



Cymodocea Antarctica. 

 (PI. XXXIIL, fig. 2.) 



Body ovoid, about twice as long as broad. Pleon terminating in 

 a triangular shield with the extremity excavated. It is of a greenish 

 colour, more or less irregularly splashed with a warm brown. 



Cephalon comparatively small and having a somewhat truncated 

 anterior margin with a small rounded projection between the 

 antennae. Eyes small, at the postero-lateral angle, which is produced 

 on to the succeeding segment. 



Thorax. The first segment arches outwards, and is half as broad 

 again as the cephalon. It is as long as the two succeeding segments, 



R 2 



