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.'[1]Bate and Westwood speak of this flagellum as having ' a slight indication of a joint at its base.'[2] Budde-Lund more correctly describes it as twojointed, 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 brightlymarked 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 encouragement of future research. They are distributed between two families, the Daphniidæas and the Chydoridæas. 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 transparence of the chitinous envelope implies that one may without rudeness inspect the internal mechanism. Besides the simpler form of their inward parts, the Daphniidæse have one branch of the second antennas four-jointed and the other three-jointed, to distinguish them from the Chydoridæ, which have both branches three-jointed. Three species representing as many genera of the Daphniidæ have to be named. Ceriodaphnia quadrangula (O. F. Müller) 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 vetullus (O. F. Müller) 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 vetula. The second of the localities just named yielded also Scapholeberis mucronata (O. F. Müller). 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.
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