Fa 
NOTES ON SOME RARE COPEPODA FROM SCOTLAND 237 
inner group are all elongate and plumose, the middle one being 
rather longer than the other two; the outer group consists of one 
elongate and two very short sete. The secondary joint is narrow, 
subcylindrical, and extends somewhat beyond the end of the basal 
joint ; it also bears six setee—three on the distal half of the outer 
margin, one small seta on the inner margin, and two apical sete, one 
of which is long and stout and one very short (Fig. 19). The caudal 
stylets are short, and the anal operculum carries a fringe of short 
bifid spines on the posterior margin (Fig. 20). 
ffabitat.—Loch Leven, Kinross-shire, along with Canthocamptus 
schmeiit, but not nearly so common. 
ReEMARKS.—This is a more typical Canthocamptus than the one 
previously described, and may be distinguished from other species 
of the same group by the structure of the first pair of swimming 
feet, as also by the bifid spines on the anal operculum, which 
appear to be peculiar to this species. 
Loch Leven is, so far, the only Scotch locality where Cantho- 
camptus minutus has been obtained ; but since its discovery in Loch 
Leven we have obtained information of its occurrence in several 
localities in England. Mr. D. J. Scourfield obtained it last year at 
Wanstead Park and in the Isle of Wight, and this year in Wales ; 
while one of the authors of the present memoir (Mr. A. Scott) has 
recently discovered it in a marshy drain near Leasowe Lighthouse, 
Cheshire. 
The genus Canthocamptus, as described by several authors, 
seems to us to be too inclusive, and to contain forms so diverse in 
structure that a revision of the genus will ere long become neces- 
sary in order to facilitate the study of the various divergent species 
of which it is composed. We need only refer to the following 
among other diversities of structure to show how heterogeneous are 
the forms at present included in this genus. Thus, for example, in 
some species the secondary branches of the antennz (posterior 
antennz) are one-jointed, and in others two-jointed. In some 
species again the inner branches of the first pair of swimming feet 
are composed of two equal or nearly equal joints, while in others 
they are three-jointed: these inner branches are in various species 
either equal in length to, or considerably longer than, the outer 
branches. Moreover, in some species the inner branches of all the 
first four pairs of swimming feet are two-jointed or three-jointed, 
while in some the inner branches of the first pair or the first two or 
three pairs are three-jointed, and of the other pairs two-jointed. In 
1880 Dr. Brady established the genus AZ¢theyella for one or two 
aberrant forms of the Canthocamptine ; but objection is taken by 
Continental authors to this genus, who regard it as synonymous 
with Canthocamptus. But Canthocamptus as it at present stands is 
not, as we have indicated, a very satisfactory genus. 
