Page:VCH Cornwall 1.djvu/338

 A HISTORY OF CORNWALL recently been added to the Cornish fauna by Norman and Dr. T. Scott. 1 Tetragoniceps malleolata, Brady, was a new species 'found amongst dredged material from a depth of 12 fathoms inside St. Agnes (Scilly Islands).' 3 Diosaccus tenuicornts (Claus), was taken ' on weeds at low-water-mark, St. Mary's, Scilly.' 3 Of Laophonte serrata (Claus), Dr. Brady says, ' This is by no means a common species. Mr. Robertson and I dredged a few specimens in a depth of I o to 12 fathoms off St. Agnes (Scilly), and likewise took a few amongst weeds at St. Mary's.' 4 L. similis (Claus) was found at the 'Scilly Islands, dredged in 14 fathoms, and plentiful on weeds between tide marks' ; 5 L. lamellifera (Claus) was obtained in dredgings from a depth of 2O fathoms among the Scilly Islands; 6 and L. hispida (Brady and Robertson) at the same locality in depths of 10 to 2O fathoms. 7 Laophontina dubia, Norman and Scott, was dredged at St. Mary's in 1 903. Normanella dubla (Brady and Robertson) occurred ' at New Grimsby and Porcressa Bay, Scilly, 14 to 20 fathoms.' 8 Cletodei limicola (Brady), was taken ' amongst the Scilly Islands ' ; C. propinyua, Brady and Robertson, ' In 20 fathoms off St. Mary's, and in 14 fathoms, New Grimsby Harbour ' ; C. linearis (Claus), amongst Algae at St. Mary's. 9 Euhydrosoma curvatum (Brady and Robertson) was procured ' off Porcressa Bay and in New Grimsby Harbour (Scilly Islands), dredged in i o to 20 fathoms.' 10 The Arpacticidae in a restricted sense include Dactyhpusia tisboides (Claus) from the 'Scilly Islands, 10 to 40 fathoms'; D. brevicornis (Claus), from the same place, between 2O and 40 fathoms ; and D. stromil (Baird) from the same locality, but procured by the surface net. 11 Concerning the last Brady says : ' Some doubt must rest upon the identification of this with Dr. Baird's Canthocamptus Stromii, but as I am unable to suggest any other species to which Dr. Baird's description might better apply, I follow the nomen- clature adopted by Dr. Claus and Mr. Norman.' Thalestris mysis, Claus, is reported from the 'Scilly Islands, dredged in 10 to 12 fathoms, and taken in the surface-net and amongst weeds at low water ' ; and T. rufocincta, Brady, from the same islands at the same depth, ' and also on algae in Porcressa Bay, St. Mary's.' In discussing the localities of T. harpactoides, Claus, Brady says : ' I have a single specimen, apparently belonging to the same species, which was dredged amongst the Scilly Islands.' There also he took T. c/ausii, Norman, and of T. serru/ata, Brady, a single specimen, a male, was ' dredged on a bottom of muddy sand in New Grimsby Harbour, at a depth of 14 fathoms.' T. longimana, Claus, was dredged by Brady abundantly at these islands, and also got in the surface-net. Of T. peltata (Boeck) ' one specimen only was found in dredged material from a depth of 40 fathoms off St. Agnes.' 12 Westwoodia nobilis (Baird) was found by Brady 'near St. Agnes (Scilly), 10 to 12 fathoms,' 13 and is also recorded by Cocks as Arpacticus nobilii (Baird) from ' Ponds on rocks, Gwyllyn-vase.' Arpacticus chelifer (O.F.M.) was found by Brady in the Scilly Islands, 14 and by Cocks ' In sea-water from Green Bank.' A. flexus, Brady and Robertson, was 'dredged in depths of 10 to 2O fathoms amongst the Scilly Islands ' ; Zaus spinatus, Goodsir, 'in 10 to 12 fathoms' ; Alteutha crenu/ata, Brady (assigned in the first instance to Peltldium was found ' On Algae near low-water mark at St. Mary's and St. Agnes (Scilly Islands), where it was also taken in the surface-net in the evening.' 1( Peltidium conspicuum, Norman and Scott, was taken in New Grimsby Harbour in 1903. To the Porcellidiidae are assigned Porcellidium tenuicauda, Claus, 'One specimen dredged off St. Agnes (Scilly) in a depth of 10 fathoms' ; P. fimbriatum, Claus, and P. viride (Philippi), both from St. Mary's. 16 In the Idyidae stand Scutellidium tisboides, Claus, found ' on weeds in Porcressa Bay,' and S. fasciatum (Boeck), also from the Scilly Islands. 17 To the Thaumatoessidae (otherwise called Monstrillidae) belongs Monstrilla rigida, Thompson, to the Corycaeidae Corycaeus anglicus, Lubbock, both rare species, recorded by Vallentin from Falmouth. Under the Ascidicolidae Canu brings the species Notodelphys allmani, Thorell. Cocks records this as N. ascidicola, Allman ; but Allman's specific name has been rejected by later authors on the ground that under it two or more species had been inextricably con fused together. To the Asterocheridae belong Dyspontius striatus, Thorell, and Acontiophorus scutatus (Brady and Robertson), ' both dredged in a depth of 40 fathoms off St. Agnes.' 1B In Giesbrecht's opinion the puzzling Nicothoe astaci, Audouin and Milne-Edwards, should stand near to this family. It is parasitic ' on the gills of the common lobster,' as recorded by Cocks, who supposes himself to have discovered a variety, which, however, he does not describe. That industrious collector further gives the names of nine species of the Copepoda commonly known as fish-lice, some of which attain a much larger size than what is common in the free-living species. Their vagaries of form no doubt add some difficulty to the study, but at the same time they stimulate observation by their oddness and help to lift this particular 1 Ann. Nat. Hist. Ser. 7, vol. xv, 284. * Man. Brit. Cop. vol. ii, p. 67. 3 Ibid. p. 70. Ibid. p. 73. 5 Ibid. p. 79. Ibid. p. 84. 7 Ibid. p. 86. 8 Ibid. p. 88. ' Ibid. pp. 92, 94, 97. 10 Ibid. p. 100. " Ibid. pp. 108, 119, 114. 11 For the species of 'Thalestris, see Man. Brit. Cop. vol. ii, pp. 123-139. 13 Ibid. p. 142. u Ibid. p. 149. 15 Ibid. pp. 152, 155, 164. 16 Ibid. pp. 166-168. 17 Ibid. pp. 177, 1 80. ls Ibid. vol. iii, 67, 71. 286