298 APPENDIX. 



undoubtedly, " one of the most remarkable among the tenants of the 

 deep. It is a genuine snake in miniature, of delicate form and pro- 

 portions, decked in lively colours." These colours are red and white 

 finely contrasted, — the red usually scarlet or vermilion, but sometimes 

 chocolate-red. The worm "forms a pale grey, thick, glossy, silken 

 sheath of considerable tenacity, reflecting the prismatic colours even 

 in artificial light. Although of ample width, the sheath does not 

 exceed a sixth part of the animal's length. Herein it reposed in un- 

 equal parallel longitudinal folds. The sheath is sometimes aban- 

 doned, either transiently or permanently, or its occupant wanders 

 about the vessel, and returns to lie there during weeks, protruding 

 the head occasionally. This covering is probably formed by an 

 exudation, very profuse, from the whole or part of the body. Not 

 only do its sides appear to be thickened by successive augmentations, 

 but the tenant repeatedly forsakes the old sheath to form a new one, 

 which in turn is deserted also." — Dalyell. 



Meckelia taenia (page 28). 



•' Length 16 inches or more ; breadth of the anterior above a line. 

 The head and sides of the anterior cleft. Mouth (genital aperture) 

 a slit below, very conspicuous. Colour from dull reddish-brown to 

 pale red ; belly paler. A white stripe traverses the whole length of 

 the back, which is divided in the centre by a dark line, thus render- 

 ing the animal very like a riband." No specks or eyes have been 

 discovered. The extremity of the anterior is white. 



" This animal takes shelter in empty shells, or in the tubes of 

 other tenants of the deep." — Balyell. 



Serpentaria fusca (page 28}. 



Body linear-elongated, flattened, nearly alike at both ends, or 

 narrowed posteriorly, the ends bluntly pointed, entire ; back rather 

 convex, of a uniform or marbled umber-brown colour, the ventral 

 surface of a faint flesh-colour or ochre-yellow. Substance opake, of 

 a firmish consistence, but very glutinous. Head continuous with 

 the body, without eyes or fissures. Mouth rather large, round and 

 puckered ; genital aperture round, comparatively small. Posterior 

 end rather more pointed than the oral. 



The body of this fine species, in spirits, has an obscure wrinkled 

 appearance, as if it were composed of very narrow annuli. It is 

 fragile, so that it is difl&cult to procure an entire specimen. The 

 specific name bicolor would have suited it better than that adopted, 

 for the back and venter are well marked, and defined by the contrast 

 in their colours. 



