A34 GEOLOGICAL SURVEY OF THE TERRITORIES. 
The eyes.—The eyes are mounted upon a stalk, and thus Nebalia may 
be said to be essentially stalk-eyed. In this respect it is similar to the 
eye of the Branchipodide on the one hand, or to the eye of the Decapoda 
on the other. They are inserted just above and slightly in front of the 
1st pair of antenne. The cornea is considerably less in extent than the 
end of the eyestalk itself, and in this respect differs from the eye of 
Decapods. 
The antenne.—The two pairs of antenne are large, well developed, 
and of nearly equal size in the female, but in the male the second pair 
extend backward beyond the bases of the caudal appendages. In the 
1st pair the stem (scape or protopodite) is seen to be composed of fine 
joints, the 1st, 2d, and 4th the longest, the 3d and 5th short. From 
the scape arises the flagellum or endopodite, which has 16 well-marked 
joints, each joint provided externally with numerous set; and besides, 
there arises from the 5th joint of the scape or stem a scale- like unjointed 
appendage, which may be regarded as an exopodite; if so, then the Ist 
instead of the 2d antenne in the Phyllocarida bear a seale-like exopo- 
dite; the 2d antenne in Decapoda bearing the exopodite. The outer 
edge of this exopodite is thickly fringed with numerous long, delicate 
sete. It thus appears that what corresponds to the sete or protopo- 
dite of the Ist antenne of Decapods consists of 5 instead of 3 joints. 
The Ist antenna of Nebalia may be compared with that of the first 
stage of the larval lobster (Smith, Pl. XV, fig. 8) at the period when 
the exopodite is short, scale-like, and single-jointed. 
The 2d antenne have a 2-jointed stem or scape (protopodite), and a 
single long many-jointed flagellum or endopodite, the basal joint a large 
one; no exopodite being present, even in a rudimentary form. 
The Ist and 2d antenne are thus seen to be quite unlike those of the 
Malacostraca, and to resemble the Copepods, in that the anterior pair 
are rather the stouter of the two; but in those Copepods with very long 
antenne it should be remembered that they are the 1st and not the 2d 
pair, as in the male Nebalia. It will thus be seen that while the anten- 
ne of the Phyllocarida are entirely unlike those of the Phyllopoda, they 
are neither closely homologous with those of the Decapoda (Iysis or 
Cuma) or the Copepoda. 
The 2d antennz of the male is said by Claus to be very long, and to 
resemble those of male Cumacee, but upon a comparison the stem of the 
antenna is in Cuma quite different in the relative length of the three 
joints. So also, while, as Claus observes, they are like the antenne of 
the Amphipoda, this resemblance is quite general; on the whole, how- 
ever, the antenne of both pair bear a general resemblance to the Mala- 
costracous type; also, on the other hand, they may also be compared 
with the more primitive Copepodous type. 
The mandibles (P1. XXXVI, fig. 4; fig. 2, md).—These are remarkable 
from the small size and weak development of the biting edge or mandi- 
ble itself compared with the palpus. The oval or biting end of the. 
protopodite is small, and armed with comparatively few and weak sete, 
which shows that the Phyllocarida probably feed on decaying animal 
and vegetable food, which is easily brushed into the mouth by their 
slight stiff bristles. The palpus, however, is enormously developed, 
extending out quite to, if not a little beyond, the edge of the carapace 
(Fig. 1). It is 3- jointed; the 2d a little longer than the basal, and 
swollen at the base, while the 3d is somewhat longer but slenderer, and 
edged with a fringe of close-set, rather stiff sete. Though soimmensely 
developed as to the palpus, and entirely unlike the mandible of the 
Phyllopoda, in which only the protopodite is developed, it may be com- 
