122 PROF. W. A. HERDMAN ON THE DISTRIBUTION 



the laboratory at the Biological Station, the stomach-contents of a number of 

 these herrings, I found in every case that the stomach contained a mass of 

 red material which was obviously, under the microscope, the broken-down 

 remains of Copepoda. A few Crab zoea were recognisable, but the bulk of 

 the material consisted undoubtedly of the Copepoda. Mr. Scott examined 

 5 c.c. of the stomach-contents for me, and found that it contained 97.) easily 

 recognisable specimens of Temora. A photograph (fig. 21), which Mr. Scott 



Fig. 21. — Temora remains from the stomachs of the Herring-. 

 From a photo-micrograph by A. Scott. 



has made from one of the microscopic preparations, shows appendages that 

 undoubtedly belong to this Copepod, while here and there in the stomachs 

 complete specimens of Temora are to be seen. It is not possible to doubt 

 that during these weeks, at the height of the summer herring fishery in the 

 Irish Sea, the fish were feeding mainly upon this species of Copepod. 



We recorded a similar occurrence off the Lancashire coast a few years ago, 

 when in July 1913, at the time of an abundant mackerel fishery off Walney 

 Island, the stomachs of some of the fish were found to be full either of Temora 

 alone or of Temora mixed with Tsias and a few other Copepoda (see fig. 19, 

 p. 198). A feu- herrings from the Port Erin fishery of July 1916 were 

 found by Mr. Scott to be feeding mainly on Calanus. 



CONCLUDING REMARKS. 



Many food-fishes are known to feed upon Copepod plankton during at 

 least some portion of their life. The Loch Fyne herrings are frequently 

 at the time of a fishery found to have their stomachs filled with TJiwhceta or 

 Calanus. Mackerel, in the English Channel and to the S.W. of Ireland and 

 elsewhere, have been recorded as feeding on Calanus. It has been shown in 

 this paper that in Hebridean Seas the mackerel and in the Irish Sea herrings, 



