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A HISTORY OF LEICESTERSHIRE usually confluent, the first antennae slender, the caudal rami usually well developed, elongated, very mobile, and bearing two or three apical claws ; in the latter the shell is mostly hard, calcareous, with an uneven surface, the eyes when present more or less separated, the first antennae subpediform, the caudal rami obsolete, forming two rounded setiferous lobes. 82 The species named by Mr. Scourfield are Cypria opbthalmica (Jurine), Cyclocypris laevis (O.F.M.), C. serena (Koch), Cypris fuscata (Jurine), Cypridopsis vidua (O.F.M.), and Candona lactea, Baird. None of these are uncommon in England. As is partly indicated by the generic names, they are rather closely allied one to another, and to make intelligible the generic and specific distinctions would overtax the space at command. In the monographs already referred to as produced by Dr. Brady alone and by that author in col- laboration with Dr. Norman, the reader will find his needs supplied. One point, however, should here be noticed. In 1868 Cypridopsis mdua was given by Brady as the primary species of Cypridopsis, and so retained by Brady and Norman in 1889 ; but in 1896, when their second volume appeared, they made it the type of a new genus, Pionocypris. Recognition of the transfer is declined by Dr. Kaufmann and Mr. Scourfield. On the other hand, Dr. Thomas Scott argues that its removal from Cypridopsis became necessary, when it was made clear that the species did not possess the principal char- acter on which that genus was founded. For, whereas the caudal rami were described as 'being quite rudimentary, consisting of two slender setiform processes springing from a common base,' which applied to two associated species, on the contrary in C. vidua ' the caudal rami consist of four setiform processes.' 33 For the remaining order, the Copepoda, Mr. Scourfield's manuscript furnishes a record of fourteen species. The first is Diaptomus gracilis, Sars, in the family Diaptomidae. This is followed by ten species and two varieties of the genus Cyclops, which is not unfrequently spoken of as if it were a kind of compendium of all the freshwater Copepoda. The names given are C. strenuus, Fischer, C. leuckarti, Claus, C. dybowskii, Lande, C. bicuspidatus, Claus, C. vernalis, Fischer, C. mridis (Jurine), C. fuscus (Jurine), C. albidus (Jurine), C. prasinus (Jurine), C. serrulatus, Fischer; C. vicinus, Uljanin, being given as a variety of C. strenuus, and C. varius, Lilljeborg, as a variety of C. serrulatus. This last species is distinguished from the others by having the first antennae only twelve-jointed instead of seventeen-jointed. Dr. Brady adopts the name C. signatus, Koch, to include both C. albidus and C. fuscus, regarding the latter as an earlier stage of growth than the former, marked by its having a simple instead of a serrated rib on the last joint of the antennae. 84 In regard to C, leuckarti, Dr. Thomas Scott has quite recently observed that specimens in the penultimate or antepenultimate stage of growth have the first antennae furnished with only eleven articulations, an evidence that this useful numerical character itself requires to be used with caution in the dis- crimination of species. From the family Arpacticidae, Mr. Scourfield records Canthocamptus minutus (= staphylinus), G.pygmaeus, Sars, and C. zschokkei, Schmeil. The proper name of this genus is Canthocampus. The account of "' Tram. Roy. Dublin Soc. (Ser. 2), iv, 65-7. " Proc. Roy. Pbys. Soc. Edinburgh, xvi, 273 (1906). " Trans. Nat. Hist. Northumb. vi, 71 (1891). 1 06