354 Messrs. T. and A. Scott on some 
smaller branch is two-jointed (fig. 4). Posterior foot-jaws 
moderately stout ; terminal joint very narrow and about three 
times as long as broad, and armed at the apex with a mode- 
rately long slender claw and two sete; the proximal half of 
the inner margin of the second joint is fringed with hairs, and 
near the distal end of the margin is a moderately long plumose 
seta (fig. 6). The inner branches of the first pair of 
swimming-feet are long and slender; the first joint extends 
to the end of the outer branches; the second joint is short, 
while the third is very narrow and nearly three times the 
length of the second joint (fig. 7). Outer branches of the 
second, third, and fourth pairs elongate; inner branches much 
shorter (fig. 8). Fifth pair large; inner:portion of the basal 
joint long and narrow and tapering towards the apex; the 
outer margin, which is nearly straight, is fringed with minute 
hairs, while four spiniform sete spring from the distal half of 
the inner margin and apex; the two upper marginal sete are 
stout and comparatively short and distinctly bifid at the end ; 
the apical seta is also short, but the lower marginal seta is 
elongate and slender except towards the base, which is 
moderately stout; the secondary joint is elongate, narrow, 
and extends somewhat beyond the extremity of the basal 
joint ; the distal end of the exterior margin is produced out- 
wards into a triangular hook-like process; there are a few 
small sete on the exterior margin and on the distal end of 
the inner margin and apex (fig. 9). Caudal stylets narrow 
and rather longer than the last abdominal segment (fig. 10). 
Habitat. Off Arisaig, Argyllshire; a few specimens from 
dredged material collected in 1892. 
Remarks, This species is at once distinguished by the form 
and armature of the fifth pair of thoracic feet; the hook-like 
process at the end of the secondary joints, as shown by the 
drawing, is characteristic of all the specimens examined, and 
the two upper sete on the inner margin of the basal joint are 
distinctly bifid; the structure of the antennules, the form of 
the first pair of swimming-feet, and the elongate caudal 
stylets also form a combination of characters not observed in 
any other species known to us. We have much pleasure in 
giving to this species the name of our esteemed friend and 
correspondent, Dr. Raphael Blanchard, of Paris. 
Thalestris peltata (Boeck). 
(Pl. XV. figs. 11-15; Pl. XVI. figs. 1-8.) 
Amenophia peltata, Boeck, Oversigt Norges Copepoder, p. 45 (1864). 
rea i Brady, Mon. Brit. Copepoda, vol. ii. p. 158, pl. liii. 
gs, 11-19. 
Description.—Female. Length *6 millim. (7 of an inch). 
