Page:VCH Cornwall 1.djvu/335

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CRUSTACEANS are without eyes and approach the next tribe by having no heart and little or no rostral sinus, Polycope orbicularis, Sars, is recorded from the Scilly Islands, 1 and Polycopsis compressa (Brady and Robertson) was 'dredged off the Eddystone Lighthouse, and amongst the Scilly Islands, 10-40 fathoms, by the two authorities who named the species.' 2 The Podocopa are divided among the families Cyprididae, Bairdiidae, Cytheridae, Paradoxosto- matidae, Darwinulidae, and Cytherellidae. The first is remarkable for the extent to which parthenogenetic propagation prevails in some of the genera. Within this family Cocks mentions Cypris vidua, Mailer, from ' Pond near Panscouth lane, etc.' ; C. fusca, Straus, from ' Ditch, Swanpool, and Gwyllyn-vase,' and C. strigata, Latreille, from the same localities. These species are now called respectively Pionocypris vidua (O. F. M.), Cypris fuscata, Jurine, and Erpetocypris strigata (O. F. M.). Argilloecia cylindrica, Sars, of which ' Pontocypris ? angusta, Brady,' is a synonym, is reported by Brady and Norman from ' off the Eddystone Lighthouse, and off St. Mary's, Scilly (B. and R.).' 3 Brady and Robertson have taken Cypridopsis acukata (O. Costa) in the Scilly Islands. 4 These two naturalists express disappointment at the results of their dredging expedition in that small archipelago. Nevertheless it. enabled them to record some sixty species of marine Ostracoda. Four of these have been mentioned above in the first tribe. The remainder we must be content to apportion among the here accepted families, with only a brief occasional note. The authors introduce them with a collective statement : ' The following list embraces all the species found in our dredging amongst the Scilly Islands, and in a littoral gathering of muddy sand from St. Mary's. The localities dredged were as follows : Off Porcressa Bay, St. Mary's, 2030 fathoms, hard sand ; SW. off St. Agnes; 810 fathoms, hard sand ; New Grimsby Harbour, 1014 fathoms, muddy sand. 5 In the family Cyprididae stand Pontocypris mytiloides (Norman), P. trigonella, Sars, and Paracypris palita, Sars. The Bairdiidae were unrepresented. The almost exclusively marine family Cytheridae, on the other hand, gave rich results. In the genus Cythere (Mttller), for C. viridis, Miiller, should no doubt be read C. lutea, Mtiller. 6 The next species named is C. a/bomacu/ata, Baird. Then follow C. peilucida, Baird, and C. castanea, Sars, as to which one may presume that the second is the true peilucida, and the first the C. confusa of Brady and Norman. 7 After these come C. porcellanea, Brady ; C. Macallana, Brady and Robertson ; C. badia, Norman, for which Fowey Harbour is added by Brady, and ' Rock pools, at Mount's Bay, Cornwall,' by Norman ; 8 C. crispata, Brady, C. Robertsoni, Brady, C. villosa (Sars), C. convexa, Baird, C. ob/onga, Brady, C. cuneiforms, Brady, C. latissima, Brady, for which Brady and Norman substitute the earlier name C. marginata, Norman ; 9 C. emaciata, Brady, C. antiquata (Baird), C. semipunctata, Brady, the last three having also been taken off the Eddystone Lighthouse, from which locality Brady and Norman add a species not in this list, C. jonesii (Baird). 10 The list as revised somewhat qualifies the criticism passed on it by its authors, who say, ' There is a distinct absence of the characteristic northern forms, and an almost equal want of such species as Cythere emaciata, Bairdia acanthigera, etc., which find their greatest development on the south coast. Cythere lutea, a common species of both the littoral and laminarian zones in most (and more especially in the northern) districts of Britain, is wanting.' All faunistic catalogues require the control of prolonged experience, and this the most skilful observers cannot acquire in one short visit. To the genus Cytheridea (Bosquet) the list attributes C. cornea, Brady and Robertson, and C. elongata, Brady, the former of which is now held to be merely a junior form of the latter and earlier named species. 11 In Eucythere (Brady) the two species E. argus (Sars) and E. decliiiis (Norman) are now both placed under the latter designation. 12 In Loxoconcha (Sars) the list gives L. impressa (Baird) ; L. granulata (Sars), for which Brady and Norman substitute L. guttata (Norman), adding the Eddystone Lighthouse as a locality for it ; 13 L. multifora (Norman), which has also been taken in ' Fowey Harbour, Cornwall ' ; 14 and L. tamarindus (Jones). Xestoleberis (Sars) yielded the new species X. labiata, Brady and Robertson, of which the chief peculiarity is ' a remarkable labiate projection of the postero-inferior angle of the shell, which is more distinctly visible on the right valve.' It was ' dredged in New Grimsby Harbour on a bottom of muddy sand, in a depth of about 14 fathoms,' and has been taken also at Falmouth by Norman. X. depressa, Sars, was also obtained, and X. aurantiaca (Baird), the latter occurring moreover off the Eddystone. Cytherura (Sars) has a plentiful supply of species in the record. These are C. nigrescens (Baird), reported also from Falmouth by Cocks ; C. similis, Sars, for which apparently Brady and Norman substitute C. simplex I Brady and Norman, in Trans. Royal Dublin Soc. (1896), Ser. z, vol. v, p. 707.

  • Ibid. p. 711. s Ibid. (1889), Ser. 2, vol. iv, p. in.

4 Ibid. p. 90, and Ser. 2, vol. v, 725. 6 Ann. Nat. Hist. (1874), Ser. 4, vol. xiii, 1 1 5. 6 Trans. Royal Dublin Soc. Ser. 2, vol. iv, 125, 135. * Ibid. pp. 126, 127. 8 Ibid. p. 131. Ibid. p. 142. " Ibid. pp. 159, 169, 130, 169. II Ibid. p. 172. "Ibid, p. 179. 13 Ibid. p. 184. Ibid. p. 185. 283