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CRUSTACEANS authors profess to have but little hesitation in referring their specimens of the first species to the earlier T. cavo/inii, Milne-Edwards and Audouin, they left it for Adrien Dollfus to restore that name in iSgy. 1 They received ' a considerable number of individuals captured by Mr. Laughrin, at Polperro,' who, they say, * informs us that they live gregariously below high-water mark, where they protect their small colony by retiring deeply within the fissures of the slaty rocks of the coast, where they collect a mass of material of a " leathery consistency " behind or within which they take shelter. When disturbed they escape and will spring to a considerable distance. This is probably done by bringing the head and tail together and suddenly straightening themselves.' I cannot remember ever having seen such gymnastics on the part of specimens which have been extracted from their pile-dwellings along with Limnoria lignorum and Chelura terebrans. The doubts which Bate and Westwood have themselves raised about their second species are not yet solved. Their third species is distinguished by Sars in 1880 under the name Paratanais hotel? Norman took it in Falmouth Harbour in i884- 3 In Tanals there are only three pairs of pleopods and the uropods have only one branch ; in Paratanais there are five pairs of pleopods and the uropods have two branches. Leptochella in these respects agrees with Paratanais, but unlike that genus it has more than two joints to the inner branch of the uropods, and in the male the chelipeds attain extraordinary length. Norman reports L. dubla (Kroyer) from Falmouth Harbour. 4 Of the Apseudidae we have Apseudes talpa (Montagu) reported by Cocks from ' Trawl refuse ; in crevices of stones, shells, etc. ; Gwyllyn-vase : rare.' Bate has taken it in Plymouth Sound. 5 In this genus there is a well- developed 'scale' on the second antennae and exopods on the gnathopods that is, on the first and and second pairs of trunk-legs. The next tribe, called Flabellifera from the flabellum or fan formed by the terminal segment and uropods, comprises several important families. Of the Anthuridae the linear Anthura graci/is (Montagu) is reported by Cocks from ' Trawl refuse, Gwyllyn-vase ; scarce,' and by Bate and Westwood as having been taken by Mr. Barlee, also at Falmouth. 6 In the Gnathiidae, Cocks, using for that family the now discarded name Pranizidae, reports ' Praniza caeru/eata, Desm. not uncommon, fuscata, Johnston. Not uncommon,' and ' Ancens maxi/laris, Mont. Gwllyn- vase, etc. rare.' Bate and Westwood say, ' Mr. W. P. Cocks found the males in crevices of rocks at extreme low-water mark at Gwyllyn-Vase, and in trawl refuse, whilst the Pranizae he took most abundantly in the neighbourhood of Falmouth, and a specimen in the British Museum, labelled P.f/avus, Bantham, Falmouth, is undoubtedly a female of this species.' 7 Why they discriminate between Gwyllyn-vase and the neighbourhood of Falmouth is not made known. Probably the three supposed species were all taken at the same locality and alike belong to Gnathla maxillarls (Montagu). In this genus the young and the females differ so strikingly from the adult males that their generic separation was excusable. The honour of detecting the mistake is due to Monsieur Eugene Hesse, as Bate was well aware, though in his ' Revision ' he allows the printers to call him M. Hepe. 8 The colour in the young is said to vary very remarkably. Montagu describes individuals of a bright blue. Bate and Westwood say, ' We have received them of a bright grass green from Mr. Loughrin, of Polperro : blue from the crevices in the slate in Plymouth Sound, and have dredged them of an ash-grey, as well as transparent and white, in five or six fathoms of water in the same locality. 9 The Cymothoid group of families is very extensive and is especially distinguished for the unscrupulous voracity which several of its members display. Of the Eurydicidae three species are known in these waters. Concerning Cirolana crane/ill. Leach, Bate and Westwood say that ' the original specimens of this species were forwarded to Dr. Leach from Falmouth (Corn- wall) by Mr. j. Cranch.' 10 Cocks found it ' in dredger's refuse from harbour, and Gwyllyn- vase bay : not common.' Bate in his ' Revision ' n does not mention this species, but instead introduces Corlolana splnipes. This is a complication of blunders, for there is no such genus as Corlolana, and the Cirolana splnipes of Bate and Westwood, which is a synonym of C. torea/is, Lilljeborg, was not ' taken at Falmouth by Dr. Leach and Mr. Cranch,' as Bate affirms it to have been, while his further statement that he himself had dredged it in Plymouth Sound is obviously transferred from his earlier notice of C. cranchil. From the last-mentioned species, Conllera cylin- dracea (Montagu) is generically separated by having the first pleopods hardened to constitute an operculum. Cocks obtained it from ' Trawl and dredger's refuse, Harbour, &c.' ; Bate by dredging in the Sound and through Mr. Loughrin from Polperro. 12 Eurydice achata (Slabber), often called E. pulchra, Leach, is said by Bate to be ' taken in pools on the coast.' 13 The genus of this pretty but savage little animal, unlike the two preceding genera, has no hooks on the second joint of the 1 Bull. Soc. Zool. France (1897), p. 207. * Crustacea of Norway (1896), vol. ii, pt. i, p. 16. 3 Ann. Nat. Hist. (1899), Ser. 7, vol. iii, p. 33;. 4 Ibid. p. 334. 5 Brit. Sess, Crust, vol. ii, p. 152. 6 Ibid. p. 162. ' Brit. Sess. Crust, vol. ii, p. 195. s Op. cit. pp. 64, 65. 9 Brit. Sess. Crust, vol. ii, p. 194. 10 Ibid, p. 298. " Op. cit. p. 65. " Brit. Sess. Crust, vol. ii, p. 306. " 'Revision.' p. 66. 275