Thomson. — On Parasitic Copepotla. 369 



about 18mm. long and 5mm. broad, and is very thickly 

 fringed on both sides with numerous setiform processes. The 

 oviferous tubes barely reach to the extremity of the abdomen, 

 and are vei-y slender and thread-like. 



No males were seen. 



The average total length of the specimens was about 

 DOmm. (nearly 4in.). 



Hab. Found on a sword-fish — Ilistioijliorus herschelii. 

 (Otago Museum.) 



Genus Lernea, Linnaeus. 



M. -Edwards, and Baird after him, give the characters of 

 the animals comprising this genus as follows : — 



Body more or less twisted, and outre in appearance, desti- 

 tute of rudimentary feet. Head furnished with horn-shaped 

 appendages, which are irregularly branched. Ovarian tubes 

 twisted together into rounded masses and placed under the 

 posterior portion of the body. Abdomen large and distorted. 



The description is incorrect as far as the appendages are 

 concerned, as all four pairs of thoracic feet are present, 

 although in a somewhat rudimentary condition. 



1. Lernea lotelhe, n. sp. Plate XXVIII. , figs. 3 and 3a. 



In general appearance this species somewhat resembles 

 L. branchialis, but the three cephalic arms are quite simple, 

 and not branched as in that species. The head is small and 

 rounded, each of the three simple arms below it extending to 

 a length of about 4mm. The neck is long and rather narrow', 

 gradually widening below, the lower portion of this segment 

 being greatly dilated and bent completely on itself. At the 

 extremity of this segment the oviferous tubes arise. These 

 are closely coiled up into two masses or rolls, each about 6mm. 

 or 7mm. long. The posterior end of the body is separated dis- 

 tinctly into an oblong abdomen. There is considerable diver- 

 sity of form in the posterior part of the body, both in the 

 extent to which it is dilated and the amount of curvature 

 exhibited. The whole of this hind portion is more or less 

 covered with a filamentous growth, part of which appears to 

 consist of natural hair-like processes, but which is mainly 

 formed of masses of filamentous Algce and of sertularians. 

 The front part of the body is very hard and horny, but the 

 hinder part is much softer and leathery in consistence. It 

 is probable that as these parasites are attached by the hard 

 head, and have the softer posterior portion projecting on the 

 outside of the fish which they infest, the growth referred to is 

 of the nature of a protective covering, resembling in this 

 respect some of the rather soft-bodied crabs {Paramithrax) 

 which are similarly protected. 

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