A HISTORY OF BUCKINGHAMSHIRE 



little white and blind lodger in ants' nests, Platyarlhrus hoffmannseggii, 

 Brandt. Mr. Webb has found it at Langley. Sars ascribes to the short 

 flattened second antennas a ' flagellum only consisting of a single joint.' * 

 Bate and Westwood speak of this flagellum as having ' a slight indication 

 of a joint at its base.' a Budde-Lund more correctly describes it as two- 

 jointed, with the explanation that ' the first joint is very minute, scarcely 

 conspicuous, very much shorter than the second.' 3 This joint is in fact 

 quite distinct, but apt to be obscured by telescoping into the preceding 

 joint of the peduncle. In this species the inner branch of the uropods 

 projects much beyond the apex of the body. 



In the family Armadillidiidas, so well known from their habit of 

 rolling themselves up into neat little globes with a pill-like appearance, 

 the customary Armadillidium vulgare (Latreille) has been sent me from 

 Eton and Lane End, the latter locality furnishing large and brightly- 

 marked specimens and some of a clear brown in the ground colour. 



For the Entomostraca of the county I have to rely exclusively on 

 lists of names. But as these have been supplied me in the most obliging 

 way by Mr. D. J. Scourfield it would be superfluous to wish for and 

 difficult to find a better authority on which to place reliance. The 

 catalogue illustrates, though very unequally, all the three orders of this 

 great group, the ' gill-footed 'Branchiopoda, the 'shell-enfolded ' Ostracoda, 

 and the ' oarfooted ' Copepoda. Of the first the only sub-order to come 

 under notice is that of the ' antlered ' Cladocera. Of these Mr. Scourfield 

 has identified thirteen species, a satisfactory instalment for the encourage- 

 ment of future research. They are distributed between two families, the 

 Daphniidas and the Chydoridas. One of the marks separating these 

 two consists in the fact that the latter have a looped intestine, while in 

 the former this convolution is not present. In both cases a glassy trans- 

 parence of the chitinous envelope implies that one may without rudeness 

 inspect the internal mechanism. Besides the simpler form of their inward 

 parts, the Daphniidse have one branch of the second antennas four-jointed 

 and the other three-jointed, to distinguish them from the Chydoridas, 

 which have both branches three-jointed. Three species representing 

 as many genera of the Daphniidas have to be named. Ceriodaphnia 

 quadrangula (O. F. Miiller) was obtained from the lake in Stoke Park, 

 Stoke Poges. In the genus to which this tiny species belongs there is 

 no distinct rostrum. In the next two genera that feature is distinct. 

 Simocepbalus vetu/us (O. F. Miiller) was found both at Stoke Park and in 

 a pond at Burnham Beeches. Its generic name, being preoccupied, has 

 recently been changed by the Rev. Dr. Norman, F.R.S., so that the 

 species must henceforth be known as Simosa vetu/a. The second of the 

 localities just named yielded also Scapholeberis mucronata (O. F. Miiller). 

 In the latter genus the valves have the junction of the hinder and lower 

 margins marked by an acute process, or at least a more or less acute angle, 

 whereas in Simosa the meeting of the margins is rounded off. 



Crustacea of Norway, ' Isopoda,' ii. 174. British Sessile-eyed Crustacea, ii. \6z. 



3 Isopoda Terrestria, p. 199. 

 116 



