258 GILBERT C. BOURNE. 



of the stomacli were full of material, including an entire 

 Crustacean, which occupied nearly the whole of the cavity of 

 the proximal limb. As the contents of the stomacli serve to 

 throw light on the habits of the animal, I examined them 

 carefully and found that the smaller stuff and debris in the 

 distal limb consisted chiefly of the fragments of Crustacea of 

 different kinds ; I could recognise fragments of the limbs and 

 mouth parts and portions of the bodies of Copepods, some 

 of which must have been of large size relatively to the 

 specimen of Oligotrema in which they occurred. The entire 

 Crustacean in the proximal limb proved to be an Amphipod 

 Avhicli had evidently been only recently swallowed, for it is in 

 a good state of preservation, the head and some of the 

 anterior thoracic somites being the only regions in which 

 signs of partial digestion are evident. As this Amphipod 

 was cut into numerous sections I' could not even determine its 

 genus with any certainty, but from what I could make out 

 of the shape of its antenna, mouth parts, and thoracic limbs, 

 from its dome-shaped thoracic segments, it^s long", back- 

 wardly directed and pointed thoracic pleura, and the shape 

 of the abdomen, the terminal segments of which are fused 

 together, and from the large size of the eyes (which, how- 

 ever, had suffered partial digestion), I shall not be far 

 wrong in identifying it as a member of the Platyscelidio, and 

 very probably it is Platyscelns (Eutyphis) armatus, 

 Claus, or a closely allied species. 



Platyscelns armatus was taken by the "Challenger" in 

 surface collections made between New Guinea and Japan, and 

 P. rissoinge was obtained by the same expedition at a depth 

 of 240 fathoms off Tongatabu. It is not unlikely, then, that 

 this Amphipod belongs to a genus of which members have 

 been found swimming on the surface or at considerable 

 depths in the Pacific. At all events there is no question here 

 of a parasitic or commensal Crustacean, such as are found in 

 the branchial sacs of so many Ascidians, The fragments of 

 Copepods found in the stomach are obviously the digested 

 remains of free-living species ; the Amphipod belongs in all 



