436 M. V. LEBOUR. 
As regards the Copepods, we naturally find that the fish with the 
smallest mouths eat the smallest forms, both large and small being 
eaten by those with large mouths. Thus Arnoglossus up to about 20 mm. 
having a small mouth does not take larger forms than Pseudocalanus, 
whereas Solea variegata at 4 mm. can eat full-grown Temora, and Scoph- 
thalmus norvegicus at 4-5 mm. can eat full-grown Metridia lucens. It is 
a striking fact that Calanus finmarchicus, which is abundant, is eaten 
very little by these post-larval fish. It is apparently too large for any 
but the fair-sized young ones. The nauplii are seen oftener as food 
for the small ones, and probably are frequently among the unidenti- 
fiable Copepod remains. Fish caught in the act of swallowing Copepods 
always show the tail sticking out of the mouth, so that they are 
swallowed head first. 
The commonest food in order of frequency is the following : Podon 
(probably intermedius), Pseudocalanus elongatus, Temora longicornis 
and EHuterpina acutifrons in the proportion of 6:4:3:2, Metridia 
lucens and Balanus nauplii coming next, and afterwards other Cope- 
pods such as Onceasp., Acartiasp. Coryceus anglicus, Centropages 
typicus, Calanus finmarchicus in order, with nauplii especially of Temora 
and in very few cases Microsetella norveqica, Harpacticus uniremis, Longi- 
pedia Scotti, Isias clavipes, Idya furcata, Orthona simalis and Anomalocera 
pattersont. Cypris stages of Balanus occurred at certain times and 
Evadne sp. Podon and Evadne are not found in the winter but most of 
the fish that had eaten Podon were in summer hauls, and the Balanus 
nauplii which swarm in spring, beginning in February, were chiefly taken 
by young herring. The Copepods most frequently taken as food are 
amongst the commonest in the ordinary tow-nettings, although the Har- 
pacticid Huterpina acutifrons occurs much more frequently in fish than in 
the tow-nettings, and the Oncea (probably media) has not been taken with 
the tow-nets here. These two and Metridia lucens are evidently com- 
moner outside, and the hauls in which the fish were taken which had 
chiefly eaten these were from the region of the Eddystone and Rame 
Head, the other common forms, Podon, Temora and Pseudocalanus also 
evidently abounding there. Besides Copepods and Cladocera small ova 
were frequently found in the fishes, especially the Pleuronectids and 
Herring ; these were spherical and usually measured about 0-2 mm. in 
diameter. The very young fish frequently contained only these. 
Very few unicellular organisms besides these ova were found in the 
young fish. Diatoms when present were sometimes in the Copepods 
eaten or in their feeces, but not very often free in the alimentary canal. 
In one instance a perfect specimen of a Coccosphera was found in a 
Pouting, Gadus luscus. On another occasion a young Ammodytes con- 
tained several Rhizosolenia Shrubsole?. 
