FAUNA OF THE CHESS AND GADE 347 



On September 12th, 1912, a white specimen with black alimen- 

 tary tract was obtained from the brook near the Canal at Hunton 

 Bridge, and on September 18th, 1912, a specimen with nearly 

 white ova was taken from Parsonage Farm Pool. It may be 

 mentioned that the colours of the ovisacs ought to be observed 

 as soon as possible after specimens of Copepods have been taken 

 and are in full vigour of life. In specimens which are dead or 

 sickly the ova lose their distinctive colour and finally become 

 bleached. 



Besides the difference in size there is is not much to distin- 

 guish gigas specimens from those of the normal type. In gigas 

 specimens from the country of the Chess and Gade, the basal 

 parts of the anterior antennae (see fig. 34) always seem to be 

 relatively stronger and thicker than in specimens of the normal 

 type, and the fifth pair of feet usually appear to be better 

 developed. At any rate, their structure can be determined much 

 more readily and easily. Variations in the relative lengths of 

 the antennse and furcal segments in both the normal and gigas 

 forms are such as do not furnish any reliable distinguishing 

 ieature. 



(To be continued.) 



