Galty Marine Lahoratori/^ St. Andrews. 157 



length, slightly tapered toward the snout and distinctly 

 diminished toward the tail and more or less rounded 

 throughout. The segments are 60 or more, and when the 

 body is extended the anterior region is nearly as narrow as 

 the snout. The tentacles are 12 in number, six on each 

 side, arise on the dorsal surface opposite each other, and the 

 bases of the pairs approach quite as closely as in Dodecaceria 

 ater. They commence on the anterior part of the second 

 segment, the first pair being longer than the others. As a 

 rule they are of a pale green colour, with darker pigment at 

 the tip, but they may be dull orange. A coiled blood-vessel 

 proceeds along the centre of each, and the edges of the 

 tentacle are often crenated, and when extended frequently 

 show^ a dilatation at the tip, but no cilia. When sickly the 

 tentacles assume a dull brow^i hue. 



The first seven bristled segments have on each side two 

 fascicles of simple bristles Avhich taper to very delicate tips. 

 In the eighth segment the ventral division has a few of the 

 peculiar bill-hook crotchets amongst the bristles, and at the 

 tenth the latter only occur in the ventral series, whilst some 

 show dorsally a few of the simple tapering bristles and about 

 three stouter bristles, the tips of which have been abraded, 

 so that an oblique surface remains. The typical crotchet or 

 hook has a slightly curved shaft, which somewhat increases 

 in diameter from the base to the distal third, then gently 

 bends backward to the neck, where the dorsal line again has 

 a backward curve, and then goes forward to the tip. The 

 anterior curve, which at the neck is also slightly backward, 

 is abruptly broken by a bold conical projection, from the 

 apex of which the distal curve runs to the stout tip. It thus 

 differs in all respects from the tip of the southern Dodeca- 

 ceria ater of De Quatrefages. 



In the posterior part of the body the dorsal setigerous 

 cone bears a few of the long slender tapering bristles, and 

 one or two stout hook-like bristles bevelled at the tip and 

 representing a modified type of the ventral series, for they 

 present no enlargement on the anteiior face below the 

 bevelled region. The ventral division likewise has a bristle 

 or two of a shorter type than the dorsal, Avhich are con- 

 spicuous in a lateral view from above, and one or two of the 

 characteristic crotchets, the only peculiarities being their 

 shortness and the more maiked curve of the less robust hook 

 at the tip. The conical projection at the anterior base of 

 the curve of the tip is marked. 



In a young example 3-4 mm. in length, procured along 



