148 



Part III. — Seventeenth Annual Report 



the Loch Katriue reading is nearly a fortnight later than that of the 

 other, which may account for at least part of this discrepancy. With the 

 exception of the first reading, however, the variation of temperature in the 

 two lochs is seen to be fairly uniform. 



Pelagic Entomostraca Captured by the Toio-Nets. 



Entomostraca and other invertebrates were scarcer in Loch Katrine 

 than in any of the other lochs examined. The following Table contains a 

 list of all the species captured by the tow-nets at both the upper and 

 lower ends of the loch. The abbreviations used are the same as in the 

 other Tables. 



Names of the Species. 



1897. 



1898. 



Lower end, 

 Sept. 10. 



Upper end, 

 Sept. 9. 



Lower end, 

 Nov. 26. 



Upper end, 

 Nov. 26. 



Lower end, 

 March 16. 



Upper end, 

 March 16. 



Lower end, 

 June 28. 



Upper end, 

 June 27. 



COPEPODA. 



















Diaptomus hircus, 



0 



0 



0 



0 



0 



f. 



0 



0 



G. S. Brady, 



















gracilis, - 



0 



r. 



f. 



r. 



f. 



fr. 



0 f 



c. 



G. 0. Sars, 

















Cyclops strenuvs, Fischer, - 



r. 



f. 



r. 



r. 



0 



0 



r. 



fr. 



,, viridls (Jurine), - 



r. 



0 



0 



0 



0 



0 



0 



0 



,, a/6 idus (Jurine), - 



f. 



0 



0 



0 



0 



0 



0 



0 



,, fimbriatus, Fischer, 



0 



0 



0 



0 



0 



r. 



0 



0 



Attheyella crassa, 



(G. 0. Sars), 



0 



0 



0 



0 



0 



r. 



0 



0 



















Cladoceea/ 



















Sida cry stall 7na(Muller,) - 



r. 



0 



0 



0 



0 



0 



0 



r. 



Bosmina longispina, - 



Leydig, 



c. 



f. 



f. 



r. 



r. 



r. 



c. 



fr. 



















Daphviafalcata, 



0 



f. 



f. 



f, 



0 



f. 



0 



c. 



G. 0. Sars, 



















Eurycercvs lamellatus, 



(Miiller), 



f. 



0. 



0 



0 



0 



0 



0 



0 



















Polyphemus pediculus, 



(Lin.), 



f. 



- 0 



0 



0 



0 



0 



f. 



fr. 



















Bythotrephes longimanus, - 

 Leydig, 



f. 



c. 



r. 



r. 



r. 



0 



fr. 



c. 



















Leptodora hyalina, - 



Lilljeborg, 



r. 



f. 



0 



0 



0 



0 



fr. 



0 



















Diaptomus hircus was only obtained once during all the four visits, and 

 it was captured with the fine tow-net. Diaptomus gracilis was, as on 

 previous occasions, usually more frequent in the gatherings collected with 

 the fine tow-net, but Bythotrephes and Leptodora were more plentiful in 

 the coarser net ; Leptodora was entirely absent from the gatherings 

 collected during the colder months. Attheyella and one or two of the 

 Cyclops, as well as Sida and Eurycercus, were probably captured near the 

 shore or by the net having been dragged through some aquatic plants. 

 The largest gathering was that collected at the upper end of the loch in 



