Page:VCH Kent 1.djvu/306

 A HISTORY OF KENT C. laevis (O. F. Miiller) from Orpington. In this genus males are common. Its species have the shell excessively tumid, contrasting with the sub-compressed form in Cypria. Oi Cypridop sis vidua (O. F. Miiller), since referred to a new genus Pionocypris, Brady in 1868 says, 'I have specimens from many different localities, ranging from Kent to Dumfries- shire,' and Cypridopsis aculeata (Lilljeborg) he records as obtained by Rupert Jones at 'Gravesend, in brackish water.' With the latter was taken a species at that time called Cypris gibba, Ramdohr, which, Dr. Brady says, ' seems to be an almost ubiquitous species, but is liable to escape observation, owing to its habit of escaping on the bottom or embedding itself in the mud or soft clay.' This has since been trans- ferred to a new genus Ilyocypris, 'the mud Cypris," and the species itself has been split into two, I. gibba, Ramdohr, and /. bradyi, Sars,' but which of the two or whether both should be credited to Kent I am not in a position to decide. Along with the preceding another species of similar habits was taken, Candona Candida (O. F. Miiller), of which Dr. Brady remarks, ' some large adult specimens, collected by Professor T. Rupert Jones in slightly brackish water at Gravesend, exhibit near the posterior extremity of the shell a peculiar reticulated pattern, very similar to that of Cytherideis nobilis (Brady), a marine species found on the coast of Crete,' the two species being also not unlike in shape and general appearance. ' The males of C. Candida,' he says, ' are much more abundant than those of any other species of the family ; they appear, indeed, to be almost as plentiful as the females.' Candona lactea, Baird, is recorded from ' freshwater pond, at Charing, Kent.' Brady observes that ' the animals belonging to this genus have no swimming power, and are very sluggish in their movements, crawling leisurely on the bottom, or on the stems of water plants or sometimes burying themselves in the mud.' On the other hand in the next genus, Pontocypris, which as the name implies is marine, the animals are quite well able to swim, though in practice they appear ' to dehght especially in a muddy bottom, and probably do not stir far away from it.' P. trigonella, Sars, was taken by Mr. E. C. Davison in the estuary of the Thames. The family Cytheridae supplies numerous species distributed among ten genera. As distinguished from the preceding family, in which the shell is generally thin, horny, and tolerably smooth, and the eyes when present are usually confluent, here the shell is generally hard, calcareous, and rough, and the eyes when present are more or less separated. In the extensive genus Cythere we have C. lutea, O. F. Miiller, from the North Foreland, of which the C. viridis of Brady's Monograph, from Girdler Sand, Thames, and the C. reniformis of Baird, from North Foreland, near Dover, are synonyms ;' C. confusa, Brady and Norman, from Margate ; * C. pellucida, Baird, from the Girdler Sand in the • Transactions Royal Dublin Society, ser. 2, iv. 106. ' Loc. cit. ser. 2, v. 727. 3 Brady and Norman, Transactions Rov. Dublin Society, ser. 2, iv. 125. « Loc. cit. iv. 126, 127. 256