A HISTORY OF CUMBERLAND 
land... Two species may possibly here be included, as Dr. Brady makes 
D. graciloides, Lilljeborg, a synonym of D. gracilis, while Dr. Schmeil 
keeps it distinct. 
Eurytemora affinis (Poppe) is reported by Dr. Brady from Burgh 
Marsh near Carlisle.’ 
In yet another family, the Pontellide, is the species Acartia longi- 
remis (Lilljeborg), of which Dr. Brady appears to regard Dias bifilosus, 
Giesbrecht, as a variety, for while including the latter name in the 
synonymy of the former he says, ‘I have no note of the occurrence of 
any species of Acartia in fresh or brackish water except in one locality, 
Burgh Marsh, Cumberland, where I took the 4z//osus form abundantly 
many years ago. wurytemora affinis occurred in the same pools and in 
equal abundance.’* Giesbrecht and Schmeil in 1898 make Acartia 
bifilosa (Giesbrecht) an independent species, in which ‘ rostral-threads’ 
are present, whereas in 4. /ongiremis they are wanting." 
In a preliminary note to the discussion of the Entomostraca from 
lake Bassenthwaite Professor Hickson remarks that ‘a complete list will 
be drawn up only when a series of gatherings are taken every month for 
two or three years.’ Further he says, ‘It is well known to fishermen 
that the lakes in Cumberland vary very considerably in their “ trout” 
reputation. Bassenthwaite is not regarded as a very good lake for trout, 
but on the other hand it contains an abundance of perch and pike. It 
would be extremely interesting if in time a systematic study of the 
relations between the fish fauna and the Entomostracan fauna could be 
undertaken.’*® As will have been seen from the foregoing accounts, the 
seasonal distribution of these small animals cannot be determined without 
rather elaborate investigation. The young and the adults are variously 
affected by light, heat, available food and the extent and other conditions 
of the tracts of water in which they reside. Against numerous and some- 
times very formidable foes they have characters, habits and places of 
retreat which supply them with some individual and temporary protec- 
tion. Fortunately for the feeding of many valuable fishes these safe- 
guards are only partially efficacious. Still more fortunately for the very 
same purpose the Entomostracan species are preserved from extinction 
not by the thrift or scruples of their voracious enemies but by their own 
prodigious fertility. Of the widely distributed Diaptomus gracilis for 
example Dr. Brady writes, ‘ By the deep-water net in depths of 50 to 80 
fathoms it is often taken in abundance, and in one instance at least 
(Talkin Tarn, Cumberland) I have seen the net come up from a depth of 
6 or 8 feet below the surface with a dense mass consisting almost entirely 
of D. gracilis, 
1 Nat. Hist. Trans. Northumberland, etc., vol. xi. pt. i. pp. 96, 98. 
2 Loc. cit. p. 108. 3 Loc. cit. p. 110. 
4 Das Tierreich, Copepoda Gymnoplea, p. 153 (1898). 
5 Ann. Nat. Hist., ser. 7, vol. ii. p. 468. 
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