FAUNA OF THE CHESS AND GADE. 425 



cephalothorax ranged from straw-yellow in some individuals to 

 sepia in others, and the ovisacs from apple to olive green, grass 

 green being the commonest shade. Specimens with a brown 

 cephalothorax and brown ovisacs have been somewhat common, 

 and chalky waters, like those of the Chess at The Moor and the 

 northern section of the Canal, have yielded large numbers of 

 specimens of C. serrulatus with the cephalothorax white or a 

 very pale brown, yellow, or green scarcely distinguishable from 

 white, and with ovisacs white or very pale. Occasional speci- 

 mens of this last type of coloration have been taken from other 

 localities. Among them were two with milk-white cephalothorax 

 and ovisacs taken on September 12th, 1912, from the brook, 

 already referred to, between Hunton Bridge and King's Langley, 

 some taken from the Cashio beds on September 16th, 1913, with 

 cephalothorax and ovisacs nearly white, and one with pale brown 

 cephalothorax and white ovisacs- taken from a pool near Shire 

 Lane Farm on October 15th, 1913. 



The above-mentioned three kinds of coloration, viz. brown or 

 yellow cephalothorax contrasting with green ovisacs, brown 

 cephalothorax and brown ovisacs, and white or very pale 

 cephalothorax and ovisacs constitute altogether not less than 

 four-fifths of the total number of specimens examined. 



The remaining fifth included some specimens presenting a 

 pleasing contrast of colours. On July 9th, 1912, a very restless 

 serrulatus with yellow cephalothorax and cream-coloured ovisacs 

 was taken from Chipperfield Common Pool. From Parsonage 

 Farm Pool one with green cephalothorax and milk-white ovisacs 

 was obtained on September 6th, 1912, and one with straw- 

 yellow cephalothorax and milk-white ovisacs was obtained on 

 September 22nd, 1912. One specimen with olive-brown cephalo- 

 thorax and milk-white ovisacs was taken from Chipperfield 

 Common Pool on September 14th, 1912. 



Finally, some specimens with blue ovisacs of various shades 

 have been obtained. One of these with pale blue cephalothorax 

 and ovisacs was taken from the brook above-mentioned. Another 

 specimen with bright yellow cephalothorax and blue ovisacs was 

 taken from Frithesden Pool on January 8th, 1913, and a third 

 obtained from Langleybury Pool on February 20th, 1913, had 

 bright blue ovisacs. 



(To be continued.) 



