186 



Part III. — Seventeenth Annual Meport 



Table showing the Total Number op Species belonging to the Three 

 Groups of the Entomostraca that have been observed in the 



DIFFERENT LOCHS. 



Names of the Three Groups of 

 the Entomostraca. 



Names of the Lochs. 



_■ 



\ 



- 



- 



- 



< 

 - 



6 

 "c 



— 



i 



<; 



T 

 z 

 — 



- 





o 



.5 

 p 



J 









Copepoda, .... 



21 



16 



16 



19 



18 



18 



17 



22 



4 



5 



4 



Ostracoda, .... 



16 



7 





9 



18 



20 



15 



10 







. 







25 



22 



30 



14 



23 



11 



29 



8 



10 



6 



Total number of Entomostraca 

























from each Loch. 



69 



48 



45 



58 



50 



61 



43 



61 



12 



15 



10 



NOTES ON SOME OF THE SPECIES MENTIONED IN THE 

 PREVIOUS LIST. 



In these notes I propose to limit my remarks chiefly to the local distri- 

 bution of the rarer species and to a few questions bearing on variation of 

 form, but some of the more common species may also be referred to. 



The Amphipoda. — The Amphipoda represented in the gatherings 

 from the lochs referred to in the preceding pages included only the 

 common Gammarus pule.''. Gammarus duebeni was not observed in any 

 of them. 



The Isopoda. — Asellus aquations was the only Isopod observed. 



The Copepoda. — Thirty-one species of Copepoda have been identified 

 in the various gatherings, and several of them — as Diaptomus gracilis, 

 Cyclops strenuus, Cyclops serrulatus, and Cantlxocampius staphylinus — 

 appear to be more or less common and generally distributed. Diaptomus 

 gracilis and Cyclops strenuus occurred in nearly all the lochs examined, 

 as well as on each of the dates that the lochs were visited. The follow- 

 ing are a few of the rarer species noticed : — 



Cyclops leuckarti. — The only loch of the present series in which C. 

 leudcarti was observed was Loch Lomond. It has, however, been 

 obtained in a few other lochs in Scotland, and has already been referred 

 to in a recent Report. 



Cyclops dybowskii, Lande. — This Cyclops has only been observed in 

 Loch Lomond, and it was observed in only one of the gatherings, but in 

 that one it was moderately frequent. C. dybowskii comes very near C. 

 oithonoides, G. O. Sars, and may only be a form of that species. 



Cyclops bicuspidatus. —This distinct species was observed in several of 

 the lochs examined. Two of its more obvious characters seem to be the 



