124? Illustrations in British Zoology. 



13 



and generally distributed. Although nearly allied to the 

 iumbricus cirratus of Fabricius, and to the Terebella tenta- 

 culata of Montagu, I nevertheless consider it distinct from 

 either; and a figure of it — the first which has appeared — 

 may therefore be acceptable to helminthologists. [Helmins, 

 helminthosy a worm ; logos, a treatise.] 



The body is worm-like, but it is remarkably distinguished 

 by the numerous long filaments which rise more particularly 

 from the anterior part, and curl around it like so many para- 

 sitical worms. These are the branchiae, or organs through 

 the medium of which the blood is exposed to the influence of 

 the air, and fitted for the purposes of life. 



The worm is represented of its natural size : it is about 

 three inches long, rather less than a quill in calibre, and of a 

 dirty brown or yellowish colour, much stained from the in- 

 ternal viscera. The body tapers a little towards each ex- 

 tremity, and is capable of extension. The mouth is naked, and 

 terminal, placed under the first segment, which may properly 

 be considered as the head of the animal, and which is marked 

 on each side with a curved black line ; but no eyes are per- 

 ceptible. The two next rings bear neither filaments nor 

 papillae. From the anterior margin of the fourth, which 

 becomes suddenly larger, arises on each side a bundle of fila- 

 ments, generally more tortuous, and of a paler colour than the 

 others, which arise from the sides of the following rings, down 

 about one fifth of the length of the animal, and a few remote 

 filaments are dispersed irregularly on the rest of the body. 

 The filaments take their rise from near the back, some from 

 the back itself, are about twenty in number on each side, 

 worm-like, tortuous or extended, unequal in length, the 

 shortest being placed anteriorly ; but the gradation is not 

 regular. They consist of a large central vessel carrying red 

 blood, surrounded by a white gelatinous transparent mem- 

 brane, and are consequently of a fine red colour ; but this is 

 liable to variation, for some, particularly the anterior bundles, 

 are often quite white, and others, again, are occasionally 



