74 W. 0. MCINTOSH. 
nature is doubtful, but it is possible they were due to degene- 
ration, though the animal appeared to be active and healthy, 
the only feature of note being the great length of the bristles 
flanking the sides and the comparative shortness of the ten- 
tacles. Some of the advanced specimens were three-eighths of 
an inch long and had thirty-two segments behind the head. 
The bristles of the long larval tufts in front seem to be more 
or less smooth in spirit-preparations. The minute spikes on 
the stronger bristles of the feet are readily seen. The bristles 
are generally in groups of three or four on each foot. 
In section the cuticle is found of considerable thickness, and 
beneath is a feebly developed circular coat, then a boldly 
marked layer of longitudinal muscular fibres, arranged in two 
dorsal and two ventral bands. ‘The long processes characteris- 
ing the feet from the seventh to the eleventh segments have 
large hypodermic cells internally, with their long axes parallel 
to that of the process. The nerve-cords form two flattened 
granular bands on each side of the middle line ventrally. 
They have the hypoderm externally, and apparently a space 
over each internaliy. The oblique muscles pass to their outer 
edges, and probably go beneath them. 
No further light has been thrown on the relationships of 
this form except that the tentacles in the most advanced con- 
firm the opinion of Claparéde that it pertains to the Spionide. 
It is apparently the larva of a species not uncommon at St. 
Andrews. 
EXPLANATION OF PLATES 6—8, 
Illustrating W. C. McIntosh’s paper, “ A Contribution to 
our Knowledge of the Annelida.” 
PLATE 6. 
Fic. 1.—Longitudinal (horizontal) section of the caruncle of Euphrosyne 
foliosa, Aud. and Ed., behind and on a level with the eyes. x 350. 
Fic. 2.—Vertical section of the caruncle, showing a somewhat radiate 
arrangement of the fibres in the organ, while inferiorly strong fibres pass 
from the trunk into it. ™ 55. 
