96 TEANSACTIONS LIVEEPOOL BIOLOGICAL SOCIETY. 



species found are none of them specially noteworthy and 

 are mostly common around our coasts. 



In connexion with this collection I would refer naturalists 

 to a paper by Prof. Herdman, F.K.S., entitled "The 

 Biological Kesults of the Cruise of the S.Y. ' Argo ' round 

 the West Coast of Ireland," in August, 1890 (Trans. 

 L'pool Biol. Soc, Vol. V., p. 181). The tow-net material 

 obtained on the " Argo's " cruise was placed in my hands 

 for examination by Prof. Herdman, the results being 

 given in his paper. As a supplement to the present 

 paper I have thought it might be of advantage to other 

 workers on the West Coast to transcribe from Dr. 

 Herdman' s paper the tabular statement of the distribution 

 of Copepoda at twelve localities visited by the "Argo." 

 The comparative scarcity of Galanus finmarchicus in the 

 "Argo" collection and the prevalence of Acartia clausii 

 and Oithona spinifrons quite bears out the remarks above 

 made respecting the distribution of those crustaceans. 

 Of the 32 "Argo" species, 15 occur also in the Valencia 

 tow-nettings (see Table II.). 



Both collections, but more especially that of Valencia, 

 furnish evidence of the truth of the remarks made by 

 Prof. Herdman in his Presidential Address to the Biological 

 Section at the Ipswich Meeting of the British Association 

 as to the relatively large number of genera of animals 

 represented by the species, in shallow waters, and its 

 bearing on the Darwinian principle that an animal's most 

 potent enemies are its own close allies. In the Valencia 

 group the 22 species recorded belong to 18 genera, the 

 genera being therefore to the species as 9 to 11, and in 

 the "Argo " group 32 species belong to 23 genera or less 

 than 3 to 4. The difference between the two collections 

 in this respect is probably to be accounted for from the 

 fact that the " Argo " collection, besides covering a widely 







