BRANCHIURA SOWERBYI BEDDARD. 287 
were none of them mature sexually, so that a comparison with Brpparp’s and 
MICHAELSEN’s specimens is in this respect impossible. I wish, however, to refer in some 
detail to the setze, the gills, the body-wall, the ccelom and its partitions, the circulatory 
and nervous systems; and to bring out certain points which are new, or in which my 
specimens appear to differ from those described by BrppARD. 
Seven specimens of this worm were obtained. In length they were, when extended, 
two inches or less, z.e. considerably longer than those examined by BepparD; one, much 
the smallest, measured only about two-thirds of an inch. They were fairly stout, in 
breadth about a millimetre or more, very contractile, with both ends tapering to a blunt 
point. In colour they were a pinkish grey, with whiter and more translucent margins. 
The prostomium is bluntly conical ; the number of segments 74-116. 
The setx are of three kinds, single and double-pointed needles, and hair-sete ; the 
needles of both forms occur in both dorsal and ventral bundles, the hair-setee only in 
the dorsal. 
The needle-setze (fig. 1) are mostly forked in the anterior part of the body, single- 
pointed needles being relatively few; in the posterior bundles the reverse is the case, 
the single-pointed being here the more numerous. In the double-pointed setee the 
outer point, z.e. that on the outer side of the curve of the shaft, is the smaller ; inter- 
mediate forms between the single- and double-pointed sete are met with, in which the 
outer point is still smaller, or, it may be, scarcely recognisable. The single-pointed 
setze and the intermediate forms are not produced from the forked sete by wear, 
since, especially in the posterior part of the body, the formation of new sete may be 
observed, and many of these have single points from the beginning. In length these 
needle-setze are about 120, in breadth 6—7u; they have the usual double curve; the 
nodulus, not mentioned by Bepparp, is distal to the middle of the shaft (distal to 
nodulus: proximal to nodulus::2:3); and the seta ends internally by tapering 
somewhat, not as shown by Brpparp in a broad square end. 
The hair-setee are a little longer (130-164) and much slenderer than the needles ; 
they are straight, and show no other distinctive marks ; they are confined to the dorsal 
bundles of the anterior part of the body, being absent from the whole of the gill-region ; 
there is never more than one in each setal bundle. 
The setal bundles begin both dorsally and ventrally in the second segment, and 
cease some distance in front of the hinder end of the animal, the last ten segments or so 
being devoid of sete. There may be as many as six needle-sete in a ventral bundle ; 
five, four, or fewer are also met with. In the dorsal bundles the most that I have 
observed is five needles and one hair-seta. 
The gills correspond in their appearance to the description given by Brpparp. 
They are not ciliated, are situated along the mid-dorsal and mid-ventral lines, and 
occupy the posterior fourth to two-fifths of the animal’s length. ‘There were from 38 
to 55 pairs, on a corresponding number of segments. In length they are about equal 
to the diameter of the body, but they diminish in size towards the anterior, and less 
je 
