A HISTORY OF KENT 



fashion. D. obtusa is regarded by Lilljeborg as nothing but one of the 

 numerous varieties of Z). pulex, and since D. propinqua is described as 

 ' in general character intermediate between D. pulex and Z). obtusa^ it 

 scarcely needs a distinctive name. Brady says, ' I have seen but one 

 male of this form . . . this has the short abdominal processes charac- 

 teristic of D. obtusa^ and appears to be the prevailing form of Daphnia 

 in Kent and Sussex. In the spring of 1897 I found it abundantly . . . 

 in ponds at Bayhall, Tunbridge Wells.' ' The same family contains 

 Shnocephalus vetulus (O. F. Miiller) found at Chislehurst by Mr. Scour- 

 field and by myself at Tunbridge Wells, and two species of Moina, M. 

 rectirostris (O. F. Miiller) and M. branchiata (Jurine), both recorded by 

 Baird from a " Pond on Blackheath." ' ' Recently Shnocephalus vetulus has 

 been renamed Simosa vetula by the Rev. Dr. Norman, its older generic 

 name being preoccupied. 



Of the next family Bosminidae Mr. Scourfield reports Bosmina 

 cornuta (Jurine) from Keston. By Lilljeborg this species is identified 

 with the earlier longirostris of O. F. Miiller. In this family, it may be 

 observed, the intestine is simple, and thereby it is distinguished from the 

 Daphniidae, in which the intestine has in front two caecal processes, and 

 from the Chydoridae, in which the intestine is looped. Unfortunately 

 our third family, the Macrotrichidae, occasionally have the caecal 

 processes and sometimes have a loop to the intestine, but often are devoid 

 of these characters. By this inconstancy they seriously detract from the 

 value of this internal apparatus as a help to classification. To the 

 Macrotrichidae belongs Ilyocryptus sordidus (Lievin), found by Mr. 

 Scourfield at Orpington. The species of this genus have neither the 

 anterior caeca nor the median loop. While the habit of hiding in the 

 mud is expressed by the generic title, the specific name sordidus intimates 

 that the bearer of it does not escape the ordinary consequence of touching 

 what is foul. This is not quite a matter of course with crustaceans, for 

 some manage to emerge from mud with their coats exquisitely glossy, 

 although the same mud clings to their dead bodies very tenaciously. 



The Chydoridae supply the county with several species. The ubiqui- 

 tous little Chydorus sphaericus (O. F. Miiller) is reported by Mr. Scourfield 

 from Hayes, Keston, Gravesend, Orpington and Chislehurst, and has also 

 been found at Great Bayhall, near Tunbridge Wells. The slightly larger 

 C. globosus, Baird, is reported by Baird from ' Pond near Bexley Heath, 

 July.' ' The same author records his own Alona ovata from ' Pond on 

 Blackheath, April 1848." Of the same genus Mr. Scourfield reports 

 A. quadrangularis (O. F, Miiller) from Orpington, A. tenuicaudis, Sars, 

 from Keston, A. rectangula, Sars, also from Keston, and A. guttata, Sars, 

 from Chislehurst. The first of these five is exposed to a twofold doubt. 

 Brady and Norman make it doubtfully a synonym oi A.rostrata (Koch). 

 Lilljeborg in his ' Cladocera Sueciae ' takes no notice of Baird's ovata, 



> Brady, Nat. Hist. Trans. Northumhirland, Durham, and Nezvcastle-upon-Tynf, siii. pt. 2, 226 (1898). 

 ' British Entomostraca, pp. loi, 102. 



> Loc. cit. p 128. « Lqc. cit. p. 133. 



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