FAUNA OF THE CHESS AND GADE. 428 



ova were obtained from Chipperfield Common Pool. In most of 

 them the combs were indistinct, and the cilia on the tail setae 

 were but slightly developed. From the entire water sample 

 only one female with well-marked combs and cilia was obtained. 

 Among a large number of ova-bearing females taken from 

 Wigginton Pool on April 28th, 1913, there were some with 

 combs imperfectly developed. On September 16th, 1913, some 

 specimens from the Cashio beds, Watford, had combs weakly 

 developed ; in these specimens the body and ova were nearly 

 white. Imperfectly developed combs were seen in some ova- 

 bearing females obtained from Cholesbury Common Pool on 

 May 26th, 1914, and in some obtained from Cos pond on May 

 24th, 1915 ; it should be noted that those from Coxpond were 

 rather unhealthy specimens. 



The next to be considered are those adult specimens having 

 the combs, tail segments, setae, and cilia unusually strongly de- 

 veloped. The combs were very strongly developed in many of the 

 specimens obtained from Boxmoor Common Pool on October 16th, 

 1912 ; these specimens had brown bodies usually of a dark shade. 

 On December 30th, 1912, many ova-bearing females were ob- 

 tained from Chipperfield Common Pool. Their combs were 

 exceedingly strongly developed, and the tail seta? were decidedly 

 longer than usual ; the tail segments of these specimens were also 

 longer and more slender than those of any other specimen of which 

 I have any record. In these specimens the cephalothorax was 

 brown, usually of a dark shade. Some specimens, with a light- 

 coloured cephalothorax, obtained from Potten End Pool, on 

 January 8th, 1913, had very strongly developed combs. The 

 tail segments were unusually long in some specimens taken 

 from Wigginton Pool on April 28th, 1913, and the combs were 

 also well-developed. From the same water sample, specimens 

 with imperfectly developed combs were also obtained, as stated 

 already. On September 30th, 1913, Berkhamsted Castle Moat 

 yielded a few specimens with clearly visible combs; one of these 

 specimens had the combs very strongly developed, and the second 

 and third tail setae were exceptionally long and well ciliated. 



When examining the tail segments of specimens of C. 

 serrulatus taken from Wigginton Pool on October 15th, 1913, 

 I noticed what seemed to be endo-parasites wandering to and 



