92 ANNALS OF SCOTTISH NATURAL HISTORY 
joints large. Posterior antenne somewhat similar to those 
of Longipedia, but the secondary branch is shorter, the width 
of the joints being greater than the length. Mouth organs 
similar to those of Longifedia. Both branches of each of 
the first four pairs of swimming-feet of about equal length, 
and, with the exception of the second pair, somewhat like 
those of Longipedia ; the first joint of the inner branches of 
the second pair very short, and armed with a stout conical 
spine about equal in length to the second joint (Fig. 2). 
Fifth, in both sexes rudimentary, consisting of a small basal 
joint, bearing in the female four sete, one of which is rather 
longer than the others, and densely plumose (Fig. 3). The 
first and fourth segments of the abdomen without spinous 
armature. Caudal stylets about equal in length to the two 
last abdominal segments, and considerably divergent. The 
animal is more slender than Longzpedia coronata, and the 
postero-lateral angles of the cephalo-thoracic and abdominal 
segments are rounded (Fig. 1). Ovisacs two, large. 
One of the most conspicuous differences between Canuella 
and Longipfedia is in the structure of the second pair of swim- 
ming feet. In Longzpedia the inner branches of the second 
pair are greatly elongated in both sexes, and form one of the 
distinctive characters of the genus, the name of which has also 
reference to this character. In Canuella, on the other hand, 
both branches are of about equal length in both male and 
female, and the fifth feet are rudimentary. Therefore, not- 
withstanding the number of important points in which the 
two forms agree, the differences described clearly separate the 
one from the other ; and, moreover, while Longzpedia has only 
one, Canuella has two ovisacs. 
Canuella perplexa, sp. n. (provisional name) Plate II. 
Figs. I-3. os 
1880. Longipedia coronata, Brady (fem.), “ Brit. Copep.” 
vol. ii p. 6, Plate XXXIV. Figs;3, 9; Plate XXO@\V3gein= 
T, 3, 9: 
The characters of the genus are applicable to the species, 
and therefore need not be repeated, this species being the 
only one known. Length, 1-4 mm. (q4gth of an inch). 
Additional Notes—(a) Males and females of a small (?) 
: 
