48 Prof. M'Intosli's Notes from the 



in wliicli tlie cephalic region differs from that of a Sabcllid in 

 the absence of a collar, for the first segment is smoothly 

 rounded on each side to the base of the branchial fans, whilst 

 ventrally a triangular process passes forward in the middle 

 line below the division between the branchial fans, and 

 dorsally a slight projection also points between the fans 

 from the anterior end of the groove. Montagu describes 

 the mouth as purple, whilst the lips are bordered with 

 chestnut. Dalyell found no tentacles, and Malnigren's 

 tentacles refer to the frilled processes on each side of the 

 mouth. 



The branchial fans appear to cling more tenaciously to 

 their bases than in ordinary Sabellids, and comparatively 

 few of the preparations are devoid of them. The filaments 

 range from twenty-one in each fan (Shetland) to thirty-seven 

 {South Devon), and they are connected by a web (which 

 Claparede states is ciliated externally) almost to the tip, as 

 in Chone. In structure each filament agrees in the main 

 with that in Sabella, the camerated chordoid axis passing 

 along its entire length, and a slender continuation of it 

 reaching to the tip of the terminal process, which has a 

 tapering web on each side, and is often deeply tinted purple. 

 The pinnse are comparatively long, and likewise have a chor- 

 doid axis (not distinctly camerated), and they taper a little 

 from base to apex. Toward the tip of the filament the rows 

 of pinnae terminate in a double series of papillse, which, like 

 the pinnte, are alternate. The branchial plumes or fans are 

 of a rich dark chocolate-brown in life, the brown being 

 chiefly confined to the filament externally, and the pinnae, 

 which are capable of independent motion, are of a rich 

 purplish red. The bases externally, however, are of the 

 colour of the body, viz., a dull orange hue. The two bran- 

 chial fans are often separated to their bases during the 

 movements of the animal. Montagu describes them as 

 singularly beautiful and of a purple colour, darkest at the 

 tips of the rays, and the pinnae of a chestnut colour, shaded 

 to purple near the centre. In the Zetlandic specimens, 2 or 

 2| inches long, the body had the diameter of an ordinary 

 quill, the branchial fan measured about \ inch antero-poste- 

 riorly, but when the fans were flatly extended laterally their 

 diameter was about an inch. 



The body in the preparations is somewhat fusiform, for, 

 besides the distinct tapering posteriorly, it is narrowed in 

 front, and in life it sometimes assumes the same outline. It 

 is rounded throughout except anteriorly, where, on the 

 dorsal surface, a groove passes backward in the middle line 



