346 HARMOTHOE SETOSISSIMA. 



Length one and a half to one and three quarters inches. 



Head (Plate XXVIII, fig. 5) somewhat like that of Harmothoe imbricata in outline, 

 only the anterior peaks are less acute and the widest region is further forward, so as to 

 give the head a more distinctly ovate form. The posterior pair of eyes are nearer each 

 other, and the larger anterior pair are more visible from the dorsum. The median tentacle 

 is of moderate length, with just a trace of a dilatation below the filiform tip, and furnished 

 with sparsely distributed short clavate cilia. The lateral tentacles are short and tapering, 

 and have a very few of the same small clavate cilia. The palpi are smooth under a lens, but 

 show very minute papilla? under a high power. The toughness and extensibility of these 

 organs are well seen in this species. The tentacular cirri also show a trace of an enlarge- 

 ment below the filiform tip, and have sparsely distributed short clavate cilia. These and 

 the tentacles are sometimes tinted brownish. 



Body rather elongate, slightly tapered in front and more distinctly from the anterior 

 third backward, and having thirty-eight bristled segments. In some the dorsum is 

 pale, but in others, as in the drawing, it is barred with brown throughout, the pattern in 

 each segment posteriorly being beautifully defined. The under surface is pale. The 

 segmental prominence is distinct, and a considerable papilla projects between the feet. 

 The body terminates in two long, tapering, caudal styles. 



The pre-gastric cseca agree with those in Harmothoe imbricata. 



Scales (Plate XXXIII, fig. 5) fifteen pairs, entirely covering the dorsum; the first 

 pair rounded, the succeeding reniform-ovate. The anterior cling somewhat firmly to the 

 pedicles. The surface is densely covered with minute chitinous papilla? (really minute 

 spines), so that it appears like shagreen under the microscope. Towards the outer 

 border a few short clavate cilia project from the edge and also appear on the neigh- 

 bouring surface. The scales are comparatively thin, but of considerable toughness. 

 They increase in size posteriorly. Their colour is often pale, but in some it is brownish, 

 and in the coloured figure the papilla? of the scales and other organs are infested by a 

 blackish parasitic growth which greatly alters the aspect. 



In two fine examples procured after a storm on the west sands at St. Andrews 

 (E. M.), the scales had a broad marginal belt in the exposed portions, leaving a large 

 ovoid pale region in the middle. The dorsum besides was richly tinted with brown. 

 Coloured examples, indeed, are more common in the north than in the south. 



Many Loxosomse occur on the scales of a specimen from the Moray Frith. 



Feet. — The first foot has a very strong spine and a group of about four short 

 bristles of the dorsal type. 



In the second foot the dorsal bristles form a dense tuft, the closely arranged spinous 

 rows and the rudimentary bare portion at the tip being diagnostic, though the bristles 

 have not attained the length of the typical forms. The ventral division consists of a 

 series of slender bristles with long, 'tapering, spinous regions, and simple slender tips. 

 Moreover the shape of the foot is peculiar, the dorsal division in lateral view forming a 

 high crest, while the ventral is distinguished by its long, acute cone projecting 

 horizontally above the spine, 



In the third foot the bifid condition of the ventral bristles is more evident, and the 

 dorsal are longer. The conical process of the ventral division is larger. By easy stages 



