CHONE. 287 
The anterior hooks (Plate CX XIX, fig. 8) are characterised by their comparatively 
short form, marked curvature of the anterior region, enlargement below the shoulder, which 
is sometimes indistinct, a main fang coming from the short neck nearly at a right angle, 
and three or four teeth on the crown above it. 
The posterior hooks (Plate CX XIX, fig. 8a) have a slightly indented posterior outline, 
a main fang and four or five distinct teeth above it. The gulf below the main fang is rounded 
and slightly narrowed at its anterior outlet. The base is nearly straight, or with a tendency 
to a shght projection where the outline turns with a curve upward to the prow. The posterior 
hooks thus approach in outline those of Huchone analis. 
Reproduction.—Southern found mature examples in September. 
So far as observed, the distinctions between this and Huchone analis rest on the minuteness 
of H. rosea, and the higher crown of the posterior hooks with the larger number of teeth 
above the main fang. The anterior shorter hooks and the narrower wing to the paddle-like 
trp of the shorter bristles are other features of moment. A comparison with the young of 
E. analis would be interesting. 
Much of the foregoing description is taken from the accounts of Langerhans and Southern, 
the latter author especially having gone into greater detail and furnished excellent figures. 
There are certain discrepancies between that described by Langerhans and the Irish repre- 
sentative, such as the absence of statocysts and eyes anteriorly, and the larger number 
of branchiz in the Irish example. 
Genus CLX XII.—Cuong, Kroyer, 1856. 
Cephalic lobe continuous, except at the dorsal fissure. Body slightly tapered anteriorly, 
and more distinctly so posteriorly, where it ends in an anus. It is more or less rounded 
throughout. A sulcus runs from the cephalic fissure dorsally and bends on the right to 
the ventral surface behind the eighth bristle-bundle, and thereafter continues in the mid- 
ventral line to the tail. The anterior region of the body has eight segments, the bristles, 
which begin on the collar-segment, are dorsal, with the rows of hooks beneath them on the 
side of the body. At the ninth the condition is reversed, the hooks being dorsal and the 
bristles beneath them. The bristles are of two kinds—dorsal with tapering tips, ventral 
with spatulate tips. The hooks, which commence on the second setigerous segment of the 
anterior region, have elongated shafts; posteriorly they are short and avicular. The 
segments are two-ringed. There are no ventral scutes. Branchiz forming a funnel, the 
filaments having a naked winged tip, but connected by a membrane for more than half their 
length. Tentacular cirri round, filiform, unequal, occasionally rudimentary or absent. 
The structure of the body-wall in Chone Fauwveli is as striking as that of Huchone. 
The cuticle covers a highly glandular hypoderm, which in the mid-dorsal groove is more 
finely granular, and may have special sensory functions. The circular muscular coat is 
-strong—Fie. 160. The dorsal longitudinal muscles are largely developed, and in two con- 
centrically arranged bands in transverse section, the outer layer, however, extending over 
the dorsum of both. The median band is somewhat triangular, with the apex internally, 
the outer is ovoid, and the alimentary canal is attached in the mid-dorsal line so closely 
