186 Prof. M‘Intosh’s Notes from the 
dilates into the long and shapely vase with the yellowish- 
green or dull yellow calcareous plate, 1°20 mm. in diameter, 
at its tip. The projection of the operculum proper beyond 
the terminal processes of the branchiz is noteworthy. In 
the ordinary spirit-preparations the pedicle hes in the midst 
of the branchial filaments, and is thus in contrast with the 
condition usually seen in other forms. The distal opercular 
plate is flat and brittle, presenting under the microscope a 
deep yellow hue and a minutely cellulo-granular aspect, the 
margin, however, being hyaline. The pedicle is flattened 
inferiorly, but toward the base of the opercular vase it is 
rounded, 
The body, which is 13-16 mm. or more in spirit, has not 
been observed in the free condition, all being moulded by 
the tube into a cylindrical form anteriorly, and ouly a little 
tapered toward the tail, which has a short, conical outline. 
The anterior region is distinguished by the six pairs of 
bristles laterally, by an anterior achetous segment, and 
by the fillet with a median notch ventrally—the representa- 
tive of the broad fold in most Serpulids. The posterior 
region consists of numerous (50-55) narrow segments, 
most of which are devoid of bristles, and it terminates in 
a somewhat broad flattened tail, with two rounded and 
sometimes prominent aval papille (cirri). The first seg- 
ment anteriorly contains the two excretory organs, the 
canals of which unite to open between the two branchial 
lobes. 
The anterior bristles dilate a little above the insertion, the 
shaft then being cylindrical to the commencement of the 
tip, which tapers to a delicate point and has narrow wings. 
The posterior region presents only one or two simple tapering 
bristles in each segment toward the tail. These bristles are 
usually slightly curved. 
The anterior hooks are numerous (220, De St. Joseph) 
in each row which runs ventrally from the bristle-tuft. 
The crown is small, the anterior edge covered with many 
(twenty to twenty-two, De St. Joseph) regularly arranged 
sharp teeth, and the main fang is well developed, though 
not sharp; whilst beneath it is a shallow gulf or notch with 
a mere rudiment of a prow before merging into the inferior 
border, which is nearly straight. The posterior outline 
presents only a trace of an incurvation, and the striz on 
the body of the hook incline from the front obliquely 
toward it. The entire hook is thin and translucent. The 
posterior hooks are fewer in number in each row, and 
