438 OJf TLYOPSYLLUS CORIACEUS AND OTHER CRUSTACEA 



broken and injured accidentally. Dr. Glaus says respecting it 

 "this pretty violet, black-pigmented Ascomyzontid " was first 

 found amongst Algae along with other Copepoda, but that later 

 he had discovered it to be parasitic upon Strongylocentrotns 

 lividus "with the colouring of which it remarkably harmonizes," 

 and he adds that Dr. Graeffe had found specimens of that sea- 

 urchin infested with hundreds of Echinoche7'es both male and 

 female. 



Ctclopicera BERNTeiEisrsis, sp. n. Plate XIII., figs. 1 — 8. 



Male. Anterior antennae seventeen- jointed, with a small inner 

 branch (fig. 2): swimming feet with both branches three-jointed 

 (fig. 5) but the outer branch of the fourth pair is short, the last 

 two joints being rudimentary and without spines, the terminal 

 joint spine-like and subulate. In other respects C. herniciensis 

 presents the usual characters of the genus. Of this species only 

 one example was found: it occurred in the same gathering as 

 the Echinocheres and, like it, was a good deal damaged. 



Arxotrogus BOECKir, G. S. Brady. 



This species I have not previously seen except from the West 

 coast of Ireland. A single specimen was found at Alnmouth 

 among Algae near low-water mark. 



Among other interesting specimens taken at Alnmouth wei'e 

 the following: — In brackish water by the side of the river were 

 found several specimens of Acartia clausii, all of which were 

 infested with what is probably an immature Trematode parasite. 

 This in its most advanced condition forms a large club-shaped 

 projection on the dorsal surface of the cephalothorax. I secured 

 only about half-a-dozen specimens of the Acartia, and from 

 these have not been able to trace completely the development of 

 the parasite, and a later visit to the locality in the hope of ob- 

 taining more material was unsuccessful. In Plate XIII. will be 

 found drawings of some of its stages. The ova of the fiuke are 

 probably swallowed by the Acartia and begin their develop- 

 ment in its alimentary canal, eating or boring their way through 

 the tissues until they appear externally. The earliest stage 

 which 1 have seen is shown in fig. 14, — a rounced, finely ore- 



