VERMES. 79 
A fine specimen, about eight inches long, had the spinous prolonga- 
gation extending about a quarter of an inch. This prolongation appeared 
somewhat muricate under the microscope. Another specimen, four inches 
long, was of a deep red purple, all except the anterior margin, which 
appeared yellowish. Its prolongation rather exceeded a quarter of an 
inch. 
A thin specimen extended about three inches, and the prolongation 
half an inch more. The colour of the anterior part was dark purple, but 
about fifteen lines of the posterior, including the prolongation, pure white. 
This latter portion had been undoubtedly a reproduction, as its com- 
mencement proved somewhat smaller than the dark part, which was 
nearly two lines thick. The specimen came from Shetland. It must 
have been large originally. 
Very faint circles were just perceptible on the body at considerable 
intervals. In certain positions there is an indistinct appearance of an- 
nulation in some of this flattened race. 
Piate XI. 
Fic. 2. Gordius purpureus spinifer. 
3. Head of the same, slightly enlarged. 
4. Posterior extremity. 
¢.—GORDIUS FRAGILIS SPINIFER.—Plate XI. Fig. 5. 
Total length three inches and half, of which the spine equals half 
an inch ; breadth two lines. Colour universally reddish-orange, unless 
a small portion of the posterior extremity, which alone with the spine 
was white. This probably indicates reproduction of a mutilated speci- 
men, which must have been of more ample dimensions, especially when 
we allot above half an inch to the spinous prolongation. 
This specimen shewed some peculiarities which I had not observed 
of others ; such as forming a very slight silken sheath, and the head 
tapering almost to a point when the animal was in motion. In quies- 
cence, the lower portion was much broadened. One or more enlarge- 
