KEPORT ON THE ANNELIDA. 
127 
and translucent, and the next four or five have the pigment-patches much less developed 
than their successors. In the typical forms there is a large ovoid, blackish, or dark 
ohve pigment-spot on the inner side of the surface of attachment; while the latter is 
characterised by a very distinct ring of the same pigment. Moreover, a series of very 
distinct whitish specks occur over the greater part of the surface, and they are especially 
evident over the dark pigment-patch previously alluded to. There are also a very few 
minute clavate papillae externally. The margin of the scale is perfectly smooth, and its 
whole structure delicate and translucent. The pigment of the dorsum, indeed, shines 
through the scales, and thus gives a very complex appearance to the coloration of the 
body, the central region of which is left uncovered throughout the greater part of its 
extent. In vertical section both cuticle and hypoderm are unusually thin. 
In some respects the structure of the foot approaches that of Achloe astericola, D. 
Oh., in others it diverges. Thus it resembles the European form in the comparative 
shortness of the foot, the proportions and shape of the cirri, and the reduction of the 
superior division; whilst it diverges from it essentially in the absence of branchial process, 
in the structure of the bristles, and in the absence of bristles from the superior division. 
About the twentieth foot the sujDerior lobe is represented by a conical papilla, into 
the base of which the tip of the superior spine enters. There is no trace of superior 
Ijristles. The inferior division of the foot differs in shape from that of Achloe astericola, 
being pointed superiorly and obliquely slanted off inferiorly. A large spine proceeds 
to the superior angle of the process, and two dense groups of bristles pass from its edge. 
The superior or smaller series consists of slender forms with elongated spinous tips, 
ending in a shghtly hooked point, the spines coming close to the latter, so as at first sight 
to give a bifid appearance to the extremity. The inferior group shows a diminishing series 
of shorter tips from above downward. So far as can be made out, the tip has a short 
terminal hook with a spur beneath, and a series of proportionally long spinous rows (PI. 
XIIa. fig. 18 ). 
At the fiftieth foot the general structure remains the same, the dorsal cirrus, however, 
being now shorter than the bristles. Between the two groups of bristles in the inferior 
division, two powerful examples occur (PI. XIIa. fig. 19), their shape and size somewhat 
resembling those that alone appear in Achloe astericola, though the differences are 
characteristic. These bristles have shafts four or five times thicker than the former 
(fig. 18). 
The chief change at the hundredth foot consists in the occurrence of only a single 
large bristle between the superior and inferior ventral groups. 
The proboscis presents the ordinary structure, and is of the average length. The 
maxillse have very prominent cutting edges running outwards from their bases. In the 
intestine the greyish debris contained vast numbers of the hairs of minute Crustacea, 
Radiolarians, various Diatoms, and shreds of tissue. 
