of the Fishery Board for Scotland. 129 
and outer branches are about equal in length, and in this pair, while the 
first and second joints of the inner branches are each provided with a 
single seta on their inner margin, the third joint bears two set. On the 
other hand, the inner margins of only the second and third joints are each 
provided with one seta (fig. 26). In the fourth pair the inner branches 
are rather shorter than the outer, and the armature of the inner margins 
_ of both branches resembles that of the third pair except that the last joint 
of the inner branches is furnished with one instead of two sete on its 
inner edge (fig. 27). 
The fifth pair are moderately large and foliaceous ; the inner produced 
portion of the basal joint is generally of a sub-cylindrical form, but the 
distal end tapers to a blunt-pointed apex from which spring two sete of 
moderate but unequal length ; the distal half of the inner margin carries 
also two moderately stout spines, as well as an elongated seta, as shown 
in the drawing (fig. 29). The secondary joint has a sub-ovate outline, and 
its extremity extends somewhat beyond the end of the inner produced 
portion of the basal joint ; it is nearly twice as long as broad and is fur- 
nished with five setee which are arranged round the distal end of the joint 
as shown by fig. 9 already referred to. 
The male somewhat resembles the female, but there are the following 
important differences in addition to the usual modification in the 
antennules :—(1) The inner branches of the second pair of thoracic feet are 
distinctly modified ; these branches in the male appear to be only two- 
jointed, the first joint is moderately stout but short, the second extends 
into a prolonged and stout tapering process which reaches considerably 
beyond the ends of the outer branches ; the first joint also bears one seta on 
its inner edge, but the elongated second joint is furnished with two (fig. 28). 
The fifth feet in the male are small; the inner portion of the basal 
joint is broadly cone-shaped and carries two apical set; the secondary 
joint is moderately broad and of a somewhat ovate form, and is provided 
with five setz, the two sete on the outer margin are short and spiniform, 
the apical seta is elongated and slender, while the two on the inner edge 
are moderately stout and appear to be plumose (fig. 30). There is also a 
small trispinous appendage on the first segment of the abdomen. 
Habitat.—Off Musselburgh, Firth of Forth ; not common. 
Remarks.—This small species seems to agree better with Dactylopus 
minutus, Claus, than with any other member of the genus, but it differs 
distinctly from that species by the structure of the antennules and of the 
fifth pair of feet in the female, and by the peculiar character of the second 
pair of feet in the male. 
Genus Thalestris, Claus (1863). 
Several species belonging to the genus Thalestris have been observed 
in gatherings recently examined, and the following are now recorded for 
the first time from the Firth of Forth. 
Thalestris peltata, Boeck. 
1864. Anemophia peltata, Boeck. Oversigt Norges Copepoder, 
p. 45. 
1880. Thalestris peltata, Brady, Brit. Copep., vol. ii, p. 138, 
pl. liii., figs. 11-19. 
1895. Thalestris peltata, T. and A. Scott, Ann. Nat. Hist. (6), 
vol. xiv., p. 351, pl. xv., figs, 11-15.; pl. xvi., figs. 1-8. 
The somewhat aberrant species of Thalestris was obtained off Mussel- 
burgh in shallow water (3-4 fathoms). Thalestris peltata appears to be @ 
I 
