of the Fishery Board for Scotland. 223 
conditions of fresh-water lochs —as Loch Ness and Loch Morar, where the 
water is of great depth, and where the shores dip rapidly, leaving very 
little or no shallow margin—do not seem to favour the development of 
the Ostracoda ; and it is ‘inter esting to compare in this respect the distri- 
bution of the marine species of the same group, which extends from the 
shore do;yn to many hundreds of fathoms. Another point of interest 
may be noted here, viz., though several species of Copepoda were obtained, 
including one or two rare Harpactids, not a single Canthocamptus was 
observed,—not even Canthocamptus minutus. Gammarus pulex—the 
common fresh-water amphipod—was also conspicuous by its absence. 
Mollusca appeared to be very scarce: the only species observed were 
Limnea peregra and Pisidium pusillum. 
LIST AND DESCRIPTION OF SPECIES. 
CRUSTACEA. 
COPEPODA. 
Family CALANIDZ&. 
Genus Diaptomus, Westwood. 
Tnaptomus gracilis (G. O. Sars). 
1863. Diaptomus gracilus, G. O. Sars, Oversigt af de indenlandske 
Ferskvands copepoder, p. 9. 
1891. Draptomus gracilis, Brady, Revis. Brit. Cyclop. and Calan., 
Pyeove  XTT figs, 7-9: Pl XIU figs, 1-8. 
Of common occurrence all over the loch, but comparatively few of the 
specimens mature. 
Family CycLorips. 
Genus Cyclops, Miller. 
Cyclops viridis (Jurine). 
1820. Monoculus quadricornis viridis, Jurine, Hist. de Monocles, 
p, 46,)Pl.,TUL, fig, 1. 
1891. Cyclops viridis, Brady, op. crt., p. 17, Pl. V. figs. 6-10. 
Common all over the loch. 
Cyclops serrulatus, Fischer. 
1851. Cyclops serrulatus, once Bull. Soe. Imp. Moscow, vol, 
KXIV. p. 423, t. x. figs, 22, 23, 26-31. 
1891. Cyclops serrulatus, Brady, op. cit., p. 18, Pl. VIL. fig. I. 
Frequent in bottom material collected at the head of the loch and at 
Brinacory. 
Cyclops ewarti, Brady. (PI. VI. figs. 1-10). 
1888. Cyclops ewarti, Brady, Sixth Annual Report of the Fishery 
Board for Scotland, Part III. p. 232, Pl. VIII. figs. I-10. 
1891. Cyclops ewartt, Brady, Revis. Brit. Cyelop. and Calan., 
p.iad. Pl, Vi, figs. 4—T, 
Gength 1°6 mh. (jth of ay inch). Seon from te dorsal view, body 
elongate, pyriform, tapering gradually to the abdomen; first cephalo- 
