160 THE VICTORIAN NATURALIST. 



the roughness of the surface or to general sterility, they were not 

 large in quantity. The crustacean most plentiful was a common 

 copepod of the genus Boekella. A fair number of Daphnia, of a 

 common small species, were found in the marginal gatherings. 

 In both open water and shore gatherings there occurred large 

 numbers of a protozoan of the class Infusoria and family Hetero- 

 tricha, which is most probably identifiable with Stentor igneus in 

 the motile stage, but it was not observed in its sedentary form. 

 The occurrence of a single form such as this in great numbers is 

 common in pools, and is due to the development of conditions 

 favourable to it in regard chiefly to food supply. In this case 

 there is little doubt that the unicellular plant Fleurococcus 

 mucosns was the pabulum. Another infusorian, of the genus 

 Amphileptus, was noticed, but was scarce. It was interesting to 

 find a single specimen of the rotifer Pedalion, sp. A small form 

 of the family Ploima was also in numbers, but is probably an un- 

 named species. 



A representative of the group Arachnida was present in large 

 numbers as a small water mite. This is a form very commonly 

 found, but owing to no worker having attempted this branch of 

 the spider family, its name cannot be given. 



Of the botanical material obtained from the reservoir itself Mr. 

 A. D. Hardy has handed in the following particulars : — 



Owing probably to the exposed nature of the shore, such plants 

 as Potomageton natans, Ottelia ovalifolia, Azolla, Lemna, &c., 

 usually found on fresh-water surfaces, were absent. Among the 

 partly submerged plants were the reed Arnndo phragmites, the 

 rush Juncus communis, and Triglochin procera with fruiting 

 spikes. Of wholly submerged plants we obtained Potomageton 

 obtusum and Nitella, sp., which was several feet in length, but 

 not in fruit. Such filamentous Algse as Spirogyra and Zygnema 

 grew along the margin, but could not be determined, owing to the 

 absence of any sign of conjugation. Of the unicellular Algse, 

 Fleurococcus vmcosus were visible with the aid of a pocket lens, 

 and appeared to form the chief food of a protozoan which was 

 present in large numbers. The genera of Desmidiaceas present 

 were, in order of frequency, Pediastrum, Micrasterias, Closterium, 

 Docidium, Stauraslrum, and Kirshneriella, the most beautiful 

 species being Pediastrum tricyclium, with individual cells grouped 

 in three concentric circles, all touching at the extremities of the 

 fronds. Among the Diatomacese the most conspicuous was 

 Tabellaria flocculosa (?), a zig-zag chain of rectangular frustules, 

 but the most numerous species was a Navicula, not yet deter- 

 mined. 



I am indebted to Miss K. Covvle and Mr. F. Chapman, A.L.S., 

 for short reports on the botany and geology respectively.*— J. 

 Shephard. 



* [These leporls will appear \i\ the next Natura/int. — Eu.] 



