114 Transactions.—Z oology. 
apex. First and second pairs of foot-jaws simple, bearing a strong apical 
claw, first of two, second of four joints. First four pairs of foot having 
both branches 3-jointed : fifth pair 2-jointed. 
1. Acontiophorus scutatus, Brady and Robertson. (Monogr. of Brit. 
‘Copepoda, vol. iii., p. 69). Pl. VIOI., figs 9-14. 
The following description is taken from Brady’s Monograph, and agrees 
exactly with our form :— 
* Body sub-pyriform ; cephalothorax broadly ovate ; head united with 
the first thoracic somite, the segment thus formed being very large and ` 
equal to nearly half the entire length of the body ; abdomen of the female 
9-jointed (of the male 4-jointed), the first segment large, and composed of 
two coalescent somites. Posterior angles of all the body-segments rounded 
off, or only very slightly produced. Anterior antennæ very short, scarcely 
one-third as long as the first segment of the body, stout at the base, and 
gradually tapering to the apex, densely clothed on the outer margin and 
apex with long fine hairs, some of which are plumose; to the seventh joint 
is attached a long curved olfactory appendage. The relative lengths of the 
various joints is represented by the following formula :— . 
Eococ* X 4 LL 6& a, a 5. M. 1HU 
9. T: 2. 1 2. 5. 24. 24 8. 3. 4, 
** Posterior antenne 4-jointed, with two strong lancet-shaped spines at 
the apex of the last joint, together with one long and four or five very short — 
set»; at the base of the external margin are also a few small sete; the 
second joint gives origin to a 1-jointed secondary branch, which terminates 
in a long plumose seta. Mandible simple, consisting of a short stout ped- 
uncle bearing a very long plumose seta.” (Mr. Brady adds, ** Probably also 
a filiform palp, though I have not seen this." I have not been able to detect 
any trace of a palp either, but have not had a sufficient number of speci- 
mens to examine.) ** Maxille composed of two stout digits (or digit-formed 
processes), one of which bears three, the other four stout, curved, and 
densely plumose sete.” Basal joints of both pairs of foot-jaws stout, ter- 
minal claws elongated, curved— Outer and inner branches of the swim- 
ming-feet nearly equal in length, 8-jointed, all the joints much constricted 
at the base, first and second joints dilated at the apex, third elongated and 
narrow; the distal margins of the first and second joints are strongly 
dentated, and in the inner branch are, at the outer angles, produced down- 
wards into sharp spines; the marginal spines of the outer branch are long 
and dagger-shaped, the last joint of both branches bearing a long subulate 
and much attenuated apical spine. Fifth pair of feet stout, 2-jointed, first 
joint shorter than broad, and bearing one long seta, second longer than broad, 
and furnished with five long, subequal, terminal sete. Caudal segments 
