Page:VCH Surrey 1.djvu/238

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A HISTORY OF SURREY divided into two tribes. These are called the Onych6poda and the Haplopoda, or the nailed feet and the simple feet, the former having four pairs of feet fitted with a basal maxillary process, while in the latter there are six pairs of feet devoid of such a process. The first tribe is limited to the family Polyphemidae, represented in Surrey by Polyphemus pediculus (Linn.), which the Quekett Club report from Woking and from Richmond Park, 1 Baird having previously recorded it in the following terms : ' Ditch near Richmond, on the banks of the Thames, nearly opposite Isleworth, July. It seems to be very limited in its range of habitat, for though this ditch is frequently filled by the tide from the river, and is fully a mile in length, I have only found it in one spot, not much above twenty yards in extent.' Of this species, notable for its great eye in front and great receptacle for the young to the rear, Dr. Baird remarks that 'the males have never yet been noticed by any observer.' Since however, ' like the Daphnitz, the Polyphemus has, at particular seasons, the ephippium, or saddle, which serves exactly the same purpose as in them,' 2 namely, to shelter the ' resting-eggs,' we may assume that the same rule applies here as with the Cladocera in general, permitting parthenogenetic development for the ordinary eggs, but re- quiring fertilization by the male for those eggs which pass through a probationary or resting period separated from the mother. Of its Ostracoda, however well provided with them in reality, Surrey cannot at present greatly boast. Baird describes and figures a new species Cypris gibbosa as taken in 1836 from a 'ditch near the Surrey Zoological Gardens' 8 ; but Brady and Norman say, 'This species is unknown to us. Dr. Baird's description may perhaps be taken to refer either to C.prasina or Cyproisjla-va.'* Cypris reptans, Baird, is recorded by Dr. Baird himself from 'the neighbourhood of London,' 6 and by the Que- kett Club from Richmond Park. 6 Brady and Norman transfer it to a new genus Erpetocypris, so that both by its generic and specific names it is now dubbed as the creeping Cypris. Baird indeed transferred it to his genus Candona, which he established for animals of this habit. He noticed that some species of Cypris were lively swimmers, and that their agility depended on the presence of a bundle of long plumose setae upon the second antennas. For these he retains the generic name Cypris. But, he says, ' the others are deficient in this apparatus, and instead of swim- ming gaily through the limpid element, crawl in the mud at the bottom of the pools in which they are found, or creep along the aquatic plants which grow there, and if dropped into a glass of water, fall to the bottom without being able to suspend themselves for the shortest time. These constitute the genus Gandona.' 7 In this genus he placed also a species called Candona simi/is, from a 'pond on Clapham Common,' 8 which Brady Q. M. C. ser. 2, vol. ii. p. 34, vol. iv. pp. 472, 273, 326. British Entomostraca, pp. 113, 1 14. Loc. at. p. 156 ; and Mag. Zool. Bot. vol. i. p. 137 (1837). Trans. Royal Soc. Dublin, ser. 2, vol. iv. p. 78 (1889). British Entomostraca, p. 161. 6 Q. M. C. ser. 2, vol. ii. p. 191 (1884). 7 British Entomostraca, p. 160. 8 Loc. cit. p. 162. 196