AMERICAN PARASITIC COPEPODA. 247 
In size my specimens agree best with LZ. Hdwardsii and L. 
alpina Olsson, but the details furnished of the latter’ forbid their 
reference to this species, while on the whole they agree very well 
with Olsson’s description of the former. This is, however, not 
accompanied by details of the appendages, and as Kurz observes? it 
is to these, and not to the form of the body or the angle which the 
“arms” make with it, that we must look for constant characters on 
which to ground valid species. I prefer, therefore, to describe the 
appendages of the present form under the above specific name, rather 
than attribute too much importance to the difference in shape of the 
ehitinous bulla in Olsson’s description. 
The shape of the body is sufficiently indicated by the outline 
sketch, Fig. 1, which also indicates the hump on the cephalothorax, 
opposite the origin of the arms. The length of the body, exclusive 
of egg-sacs, is 4 mm., of the egg-sacs 2 mm. (they are probably some- 
what more shrunken in proportion by their preservation in alcohol 
than the body), while the arms are about 2} mm. long. The 
position of the lst and 2nd pairs of antenne, and of the projecting 
upper lip, in relation to the anterior border of the cephalothorax, 
may be seen from the outline sketch from above, Fig. 2. The Ist 
pair of antennz are much more easily studied from above than from 
below, owing to the lateral projections from the upper lip, a, Fig. 3, 
which nearly conceal them from that aspect. They measure 0.07 
mm. in length, are indistinctly 3-jointed, and bear on the rounded 
end of the terminal joint 3 minute spines, of which the median one 
is distinctly articulated to the antenna, v, Fig. 3. The second pair 
of antenne may be most conveniently examined from below and 
from the side. They consist of a thick stem indistinctly 3-jointed, 
the basal joint being far the longest, and alone provided with a 
chitinous plate (ch, Fig. 3), and of two short branches, dorsal and 
ventral (d and v, Figs. 3 and 5), of which the dorsal is the longer 
and inore internal of the two. It is composed of one joint, the 
rounded extremity ef which is provided with numerous curved 
chitinous points for the most part directed inwards. The ventral 
and more internal branch has two joints, ef which the terminal one 
(¢, Fig. 5) is more palp-like than the other parts of the antenna, 
1 Ofversigt af K. Vetensk. Akad. Forhand, 1877, No 5, p. 82, Figs. 9-13. 
2 Studien tiber die Familie der Lernxopediden, Zeit. f. Wiss. Zool., B. XXIX., p. 382. 
