FABRICIA SABHLLA. 267 
Posteriorly it terminates in a rounded pygidium which has two eye-specks. The alimentary 
canal is straw-yellow, is wide anteriorly, bulges here and there in its course, and then narrows 
posteriorly. On each side of it is a red blood-channel. The body-cavity is filled with a vast 
number of granular cells about 9% of an inch in diameter. In front of the eyes at the 
base of the branchial lobes is a blood-sinus (branchial heart of Ehrenberg and Claparéde), and 
Langerhans counted twenty-five pulsations per minute. The blood is stated to be red by 
Mecznikow and Claparéde, whereas De St. Joseph says it is green. 
The first segment is devoid of bristles, but the second has a tuft on each side about the 
middle of the segment. These bristles (Plate CX XVIIL, fig. 7) are few, simple and translucent, 
with straight shafts, finely tapered tips and narrow wings. ‘The tip in some views is bent 
at a slight angle to the shaft. Eleven segments are provided with them, the first and last 
having none. As usual in the family, the posterior bristles have the longest and most finely 
tapered tips. The minute anterior hooks (Plate CX XVIII, fig. 7a) are about six in number 
in each segment, have a comparatively large head, a constriction at the neck, then a well 
marked shoulder, after which the long curved shaft tapers inferiorly. The main fang is large, 
and the crown is flat, with about four teeth. The organ is a miniature representative of 
that of Chone. 
The last three bristled segments have instead of the long hooks in front peculiar forms 
(Plate CXXVIII, fig. 76), the posterior outline being incurved and the anterior slightly 
convex, whilst the crown is long and minutely toothed, no differentiation occurring between 
the lowest and the adjoining teeth. The base enlarges inferiorly, and is occasionally split, 
apparently from the pressure used in preparing. 
Reproduction.—The sexes are separate. In August the males in the Gouliot caves of 
Sark had the ccelom filled with nearly ripe sperms. 
Mecznikow (1865) describes and figures in the fifth segment of a ripe male two ducts 
which he terms vasa deferentia, apparently leading from the ccelom to the exterior. These 
in the female were smaller. In connection with the circulation he figures a branchial heart 
on each side anteriorly, the single dorsal of the region splitting into a trunk to each anteriorly, 
whilst after a brief course it divides into two dorsal trunks. The ventral is single, the dorsals 
looping at the tail to join it. In the middle of the body it is lacunar (the author probably 
referring to the alimentary smus). Throughout the body a branch in each segment connects 
the main trunks. Two segmental organs occur in the anterior region, and he mentions 
that Leydig and Leuckart thought them connected with respiration. 
Claparéde describes the male organs as in pairs from the third to the ninth segments. 
De St. Joseph (1894) found a young example 0°74 mm. in length with large black anterior 
eyes, and two on the anal segment. The head is rounded. A single large branchia is present 
with rudiments of ciliated barbules. 
Habits—When placed in a vessel, it crawls about with the tail first, the branchial fan 
being drawn together and dragged behind. 
Mr. Arnold Watson notes that the annelid sometimes leaves its tube and burrows tail- 
first through the surrounding soft mud. The building of its tube is done by means of the 
large triangular under lip beset with long, powerful cilia which are under control. The 
annelid stretches its body well out of the tube when anxious to grasp certain particles— 
even on the tube of another, and appears to take a firm grip of the particle. Having secured 
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