E. IMPEEIALIS. — MISCELLANEOUS NOTES. 85 



idse and yet is not exactly admissible into either family. 

 The body of the Crustacea, which may be about 40 ram. long, 

 is laterally compressed ; the keeled cephalon is bent in Inimp- 

 like manner and supplied with a small rostrum ; the eyes are 

 exposed, not covered by the prolongation of the cephalic cara- 

 pace ; the mandibles with palpi; the third maxilliped robustly 

 developed ; the first leg clielate and symmetrically paired ; etc. 

 A noteworthy circumstance is the fact that this Crustacea occurs 

 each time singly in the gastral cavity — not in a pair as is usually 

 the case with Spongicola venusta of E. marshalli and E. oweni. 

 The Crustacea was only exceptionally absent in the larger 

 specimens of the sponge but quite frequently in the smaller 

 under 15 mm. body-length. A certain relation seems to exist 

 between the size of the inmate and that of the host, probably 

 as the result of the former entering the latter when both are yet 

 small and their continuing to grow together. 



Once an oxyrhynchous crab, Chorllia (closely resembling 

 C. longipes Dana), was found instead of the Macroura. Among 

 the other inmates Ophiurous were not uncommonly represented 

 by two or three different species at a time. 



