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Show 1899.] PARASITIC COPEPODA ON PISHES. 44l In the family Lernaeidae, I have united the two genera Lernceenicus and Lernceonema under the older name, following the views set forth in the able paper by Bichiardi in 1876. Five genera of this family are represented by single species. In the family Chondracanthidae (p. 488). the older name of Sphyrion has been retained for Kroyer's Lesteira. T w o species are given, specimens of both being now in the British Museum-one, the larger (by far the largest of all these Copepod parasites), is from N e w Zealand, and is probably of the same species as that obtained by Guerin off the Cape of Good Hope, having few lobed processes on the float-like head. The second was taken off Dungeness; it is much smaller, with a greater number of lobe-lika processes, and is described as S. lumpi Kr. The position of the long known Chondracanthus triglce has been for many years a disputed point. Linnaeus placed it with the Lernaeas : Blainville described it as a Lernentoma, Milne- Edwards as a Chondracanthus, Heller thought it probably a species of Medesicate, and J. Steeiistrup placed it between Lesteira and Medesicate. The animal differs from every other, except Thero-damus, in having the anterior part of the head with the hook-like posterior antennae separated by a long neck-like process from the mouth, which is placed at the juncture of this with the thoracic portiou-a peculiarity pointed out by Milne-Edwards and others, differing thus from Medesicate and Chondracanthus; I have therefore placed it iu a genus of its own-Oralien. In the family Lernseopodidae, as I have pointed out before, it is impossible to differentiate the genus Brachiella from Anchorella by the female alone, the union, complete or otherwise, of the second pair of maxillipeds not being characteristic, though the males are quite distinct, and should be always looked for and recorded. Many of the Anchorellce are very superficially described, and are very indefinite. The genus Thgsanote has been made to embrace a number of peculiar forms which have been placed with Brachiella. The genus Cestopoda of Kurz has been added. While in India I obtained on two occasions specimens of this peculiar genus from different fishes ; these have not yet been described. I have provisionally placed here the Naobranchia cygniformis of Hesse, but it is insufficiently described. Family I. EBGASILLLLE. Cephalothorax pyriform or flattened, first segment the largest; nearly or wholly provided with limbs. Anterior antennae of moderate length, 5- or 6-jointed, alike in both sexes. Posterior antennae with 3 or 4 joints. Second maxillipeds in the form of hooks, generally 3-jointed. Fifth pair of thoracic limbs one-branched or sometimes rudimentary. Eye median, with two lenses. Sex-organs paired. Female with two egg-sacs. Young as a free-swiinming larva. Male smaller than female and less freely locomotive. |