86 VERMES. 
The body is environed throughout by a number of pure white circles, 
commencing at the head.—Fig. 8. A longitudinal dorsal line, a ventral 
line, and two lateral lines, all nearly equidistant, and pure white, also 
traverse the length of the body. Many of the circles are double. A row 
of minute white specks, beginning at some distance from the head, inter- 
poses between each of the lateral and the dorsal lines.—Fig. 9. Some 
specimens have no white specks ; and, when present, they give the whole 
a very ornamental appearance. 
This animal adheres to substances but slightly in the course of its 
motion, whence, combined with its figure and specific gravity, it has 
difficulty in ascending the side of a glass vessel. 
The mouth of this animal is in the very extremity. It opens with a 
wide horizontal gape, as if the creature had an upper and under jaw. This 
was well exposed by a very fine specimen—not inferior to any I have 
ever had brought to me—on the 27th June 1850. 
Ova.—This specimen has ruptured into several pieces. A number, 
perhaps 1000 or 1500 most minute reddish-brown ova, appeared in the 
vessel to day (June 29.), of which I set some apart in watch-glasses. 
The Gordius anguis forms a pale grey thick glossy silken sheath, of 
considerable tenacity, reflecting the prismatic colours even in artificial 
light. Although of ample width, the sheath does not exceed a sixth 
part of the animal’s length. Herein it reposed in unequal parallel longi- 
tudinal folds. 
The sheath is sometimes abandoned, either transiently or perma- 
nently, or its occupant wanders about the vessel, and returns to lie there 
during weeks, protruding the head occasionally. This covering is proba- 
bly formed by an exudation, very profuse, from the whole or part of the 
body. Not only do its sides appear to be thickened by successive aug- 
mentations, but the tenant repeatedly forsakes the old sheath to form a 
new one, which in turn is deserted also. 
The fine specimen, Plate XIII., had originally concealed itself in the 
empty sheath of the Terebella conchilega, of which I was ignorant until it 
spontaneously issued forth. It survived three months, and then perished 
from the excessive heat of the weather—others have survived a long time. 
