310 BULLETIN OF THE 
pound eyes are of huge dimensions, and supported upon short, thick 
stalks. The abdomen is composed of six segments only, the telson be- 
ing not yet clearly separated from the preceding segment. The width 
of the abdomen suddenly diminishes at the fourth segment. The sixth 
segment consists of a long, cylindrical piece, which terminates in a broad, 
triangular fin. The hind border of the terminal fin is slightly convex, 
the angles truncated and notched. It is armed with fourteen long sete, 
which are finely feathered on both sides, excepting the outer two pairs, 
which are feathered only on the inner side. The spaces between the 
long sete are slightly concave, and furnished with about four very mi- 
nute sete (Pl. I. Fig. 18).* The anus lies on the lower sido of the base 
of the terminal fin, and the intestine shows through the transparent 
shell as a slender tube passing in a direct line from the stomach to the 
anus. 
The first pair of antenne (Pl. I. Fig. 15) are short, simple, composed 
of a large basal segment followed by a small, oval, setiferous, terminal 
segment. The distal end of the proximal segment also bears a long seta 
on the inner side of, and longer than, the terminal segment. 
The second pair of antenne (Pl. I. Fig. 16) are about as long as tho 
first pair. They are composed of a short basal segment which bears 
two branches. The inner branch (r2), which develops into the flagellum 
of the second pair of antenne in the adult, is a slender piece tipped with 
a long seta. The outer branch (re), which represents the ‘ scale,” is 
at this stage much larger than the inner, divided into segments for some 
distance from its tip, and furnished with sete on its inner border. 
The mouth is bounded in front by a large, prominent, triangular 
labrum (PL I. Fig. 17, 26). The mandibles (Pl. I. Fig. 17, 177) are 
slender, and taper gradually to the tips, which are armed with three 
teeth. There is no trace of a mandibular palpus at any stage in the 
development. 
The first pair of maxille (Pl. I. Fig 17, 7V), consist of two lobes, the 
outer of which bears a one-jointed palpus. Both lobes, as well as the 
palpus, are furnished with sete on their borders. 
The second pair of maxille (Pl. I. Fig. 17, V; Fig. 12) are composed 
of an inner plate, the inner edge of which is divided into five lobes, and 
an outer plate, the scaphognathite, which lies under the carapace and 
projects far beyond the inner plate toward the eye-stalk. All the 
lobes are beset with sete. The scaphognathite is in constant motion, 
* The caudal fin of the first zota-stage of Palamon serratus is figured by P. 
Mayer (op. cit., Jena. Zeitschr., Vol. XI. PL XV. Fig. 49). 
