182 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



bottom, off Dursey Head), several tow-nets, microscopes, 

 boxes of bottles, jars and tubes, a swinging aquarium, and 

 the usual preserving and mounting re-agents. 



The " Argo " started from Greenock at 5 a.m. on 

 Thursday, August 7th, and spent the rest of the month in 

 coasting round the north, west and south of Ireland. The 

 annexed map (Plate VIII.) shows approximately the 

 course, and the numbers 1, 2, 3, &c, indicate the 

 successive stations at which tow-net gatherings were 

 taken, while the letters A, B, C, &c, mark the localities 

 where we were able to dredge or trawl or collect shore 

 specimens. 



Mr. I. C. Thompson has kindly gone over all the tow- 

 net gatherings for me, and has drawn up the lists (p. 185, 

 &c.) of the species found at the different stations, which 

 are arranged in chronological order. Mr. Thompson has 

 also compiled the table on p. 194 which shews the distribu- 

 tion of the species of Copepoda over the various districts 

 explored. Among the rarer forms attention may be 

 drawn to Pontella wollastoni, Pseudocyclops obtusus, 

 Monstrilla rigida, and Porcellidium subrotundum. 



On several occasions we used two tow-nets, the one 

 made of fine silk and the other of a coarser material, 

 simultaneously, one on each side of the ship, and found 

 that the finer net invariably contained by far the most 

 material or "plankton." The coarser net only captured 

 a few of the larger animals, such as Megalopa, Sagitta, 

 and Pleurobrachia, so we soon gave up using it. 



[In his recently published work, entitled " Plankton- 

 Studien,"* Hseckel introduced a number of new terms 

 applicable to the assemblages of forms collected by the 

 tow-net, which will probably be found useful as giving 



* Jena : Gustav Fischer, 1890. 



