104 Transactions.—Zoology. 
Integument very strong, smooth, opaque-brown in colour. Length, 
4g Of an inch. Ovisac single. 
Hab. Dredged in Dunedin Harbour; not rare, but easily overlooked 
on account of its colour. 
Genus Thalestris, Claus. 
Body usually slender and elongated. Anterior antenne 8- or 9-jointed ; 
inner branch of posterior pair 2- or 8-jointed. Mandible-palp large, 2- 
branched. Maxille strongly toothed, palp usually terminated by a large 
claw. Anterior foot-jaws ending in a strong claw, and bearing several 
setiferous marginal processes. Posterior pair forming a strong prehensile — 
hand. First pair of feet with both branches 8-jointed, and furnished at the 
extremities with strong prehensile claws; first joint of inner branch much 
elongated, second and third very short; first and third joints of outer branch 
short, middle greatly elongated. Second pair in the male have the third 
joint of the inner branch wanting or very much reduced in size, and con- 
verted into two or three strong spines. Fifth pair of feet 2-branched, 
foliaceous ; much reduced in size in the males. Ovisac single. 
1. T. forficula, Claus. PI. X., figs. 16-21. 
(Thalestris forficula, Claus. Die frei lebenden Copepoden, p. 131, taf. xvii., figs. 7-11). 
Body rather slender; abdomen long, narrowing very gradually, poste- 
rior margins of the segments pectinated with rather long teeth; rostrum 
acute, of moderate length. Anterior antenne 8-jointed; in the female 
tapering gradually, and furnished with numerous sete, the basal joint 
about four times as broad as the apical, fourth joint bearing a long auditory 
seta; in the male the joints are irregularly swollen and bent. Posterior 
antenne rather strongly spined on the lower margin; secondary branch 
small, 2-jointed, and bearing 4 sete. The posterior foot-jaws have a short 
basal joint, and a rather stout hand, furnished with a single long seta in 
the middle of the inner margin; terminal claw long and slender. First 
pair of feet with both branches long and slender; the outer, which is much 
the longer of the two, has the basal joints greatly elongated, and the second 
and third very short and apparently anchylosed, the basal joint bears a single 
rather short seta on the inner margin above the middle, while the terminal 
joint carries two nearly straight claws of unequal length; inner branch 
with the middle joint very long, toothed along the outer margin, terminal 
joint bearing four slightly curved and toothed claws. Feet of fifth pair 
with the outer joint large and oval in the female, and extending to half the 
length of the abdomen. Caudal forks short, and somewhat divergent. 
Central caudal sete nearly as long as body, swollen just beyond their basal 
articulation, and marked along the greater part of their length with annular 
articulations ; outer sete about half as long as inner and lying very close to 
it. Length, J, of an inch. 
