FAUNA OF THE CHESS AND GADE.- 165 



oral part ; the peripheral parts of the lorica were very clear and 

 transparent. A cervical, bright red eye-spot was very conspicuous. 

 The dorsal gap of the oral part of the lorica was but imperfectly 

 seen, the Eotifer's head never being sufficiently retracted to 

 expose it. The rounded notch of the dorsal plate was visible, 

 and from it projected a rather short, jointed foot carrying two 

 blade-like toes. No setae were detected on the foot. The length 

 of the Eotifer was about ^-inch. 



The forty-four species so far described in these notes repre- 

 sent much of what I have done on the Eotifera of the country 

 of the Chess and Gade. With the exception of a few of them, 

 e. g. (Ecistes stygis and Brachionus quadratus, they are Rotifers 

 which any collector may find with the exercise of a little patience, 

 and are fairly representative of the rotiferan fauna of the dis- 

 trict. There are other species already found, notably Philodina 

 roseola, Coclopus porcellus, and Anurcea curvicornis, on which 

 my rough notes are not sufficiently full. I hoped to be able to 

 continue collecting specimens of these and other species, but 

 since August last my opportunities of collecting have been 

 very few. 



A great deal depends on chance when collecting forms of life 

 of any kind, and, in this connection, one of the most interesting 

 phenomena in the distribution of Eotifers is the sudden appear- 

 ance of numerous specimens where for some time before only 

 a few specimens of a species have been obtained. Several 

 instances of this kind have been given in the preceding notes, 

 e. g. the enormous numbers of Brachionus rubens in a pool near 

 Potten End, and of Brachionus pala at Coxpond, and the large 

 numbers of Pterodina patina in Langleybury Pool, of Anurcea 

 brevispina in Hastoe Pool, and of Eretmia cubeutes and Noteus 

 quadricornis in Parsonage Farm Pool, Abbot's Langley. Another 

 instance, relating not to the Eotifera but to the Protozoa, is 

 sufficiently interesting to deserve mention. On many occasions 

 I had obtained a few specimens of Bursaria truncatella, Ehren., 

 from the pool at Chipperfield Common. On December 30th, 

 1912, however, a calm, fairly fine day, with the temperature of 

 the air 46° F., and that of the water of the pool 44*5° F., I 

 obtained hundreds of the above-mentioned Protozoa in every 

 water sample taken. Nothing like this was seen by me before 



