OFK THE SOUTH-WEST COAST OE IRELAND. 321 



relations. It seems to be entirely destitute of either a manubrium 

 or radial canals. A few specimens of Arachnactis alhida, a form not 

 uncommon at Plymoutli, were taken in each catch. 



Of Siphonophora I only obtained two species. One, a Mono- 

 phj'sid which is sometimes found at Plymouth, seems to be Muggixa 

 {Diphyes) Eochii, Will. ; the other is an Anthophysid. The latter 

 broke into fragments in the process of preservation, and I cannot 

 determine its species with accuracy. The palpons bear distinct 

 conical eye-spots, which would point to its being a near ally of, if 

 not identical with the Athoryhia ocellata of Haeckel. I have never 

 seen a member of the Anthophysidas in the neighbourhood of Ply- 

 mouth. 



The absence of pelagic Radiolaria at Plymouth has often engaged 

 my attention. In the " Research " I found the following well- 

 known species in tolerable abundance : — ThalassicoUa nucleata, 

 Huxley ; Collosphsera Ruxleyi, J. Miiller ; Sphserozoum punctatum, 

 J. Miiller ; AcantJiometron elasticum, Haeckel. In addition to these 

 were several species of Oeratium. 



It is apparent from the foregoing that the surface fauna at the 

 entrance to the Channel has a distinct facies, and is different from 

 that nearer the shores of England. A more extended investigation 

 of the surface fauna from the Channel to the Atlantic would pro- 

 bably yield some very interesting results. It may be found that 

 many oceanic species are carried up in mid-Channel, as they are 

 certainly cast ashore in some seasons near Brighton. I have noticed 

 at Plymouth that there is generally a considerable difference between 

 the shore tide and the Channel tide, the latter of which runs three 

 hours later than the former. The Channel tide is almost invariably 

 richer both in amount and variety of pelagic life. There is every 

 reason to believe that the movements of mackerel and pilchards are 

 largely influenced by the distribution of the pelagic fauna, and in 

 proportion as we obtain a more extended knowledge of the latter we 

 may expect to learn more of the still mysterious migrations of these 

 fishes. During the cruise we saw on two or three occasions shoals 

 of fish at a little distance from the ship ; probably they were 

 mackerel which were feeding on the abundant surface fauna. The 

 sea, also, was full of the ova and larvae of Teleostei. Most of the 

 larvae were Gadoids, but of what species it is impossible to say. 

 Without a much more extended knowledge of facts it is impossible 

 to assert anything about the relations of fishes and surface fauna, 

 but it seems at least reasonable to suppose that the winter pilchards 

 which strike on the south coast of Cornwall, fat and in excellent 

 condition, have come from the rich feeding-ground afforded by the 

 set of the Gulf Stream into the Bay of Biscay. 



