82 SUPPLEMENT 



established by Linnaeus for a tolerably great number of ver- 

 miform animals, belonging to our author's red-blooded worms, 

 or annelida, which live upon our coasts, sometimes imbedded 

 in the sand. This genus, adopted by all zoologists, but 

 rectified, and pm-ged of the species not naturally belonging 

 to it, may be thus characterized : body elongated, subcylin- 

 drical, inflated in its anterior third part, attenuated behind ; 

 head not very distinct, but yet formed of three segments; 

 thorax of twelve, and provided underneath with a sort of 

 sternal scutel, lengthened as far as the twenty-first ring; ab- 

 domen cylindrical, and composed of a great number of articu- 

 lations ; mouth subterminal, bilabiate ; upper lip advanced, 

 and furnished above with a great number of unequal and 

 filiform barbies, cleft underneath, and prehensile ; no tenta- 

 cula ; gills in the form of arbuscula, two in number, or four, 

 or six, disposed in pairs on the first, second, or third thoracic 

 ring ; feet dissimilar ; the thoracic, with two compound oars, 

 the dorsal with subulate setae, the ventral, with a double rank 

 of hooked setae, and the abdominal consisting of hooked setse 

 simply; the tube cylindrical, open at the two extremities, 

 membranaceous, and invested with large grains of sand, and 

 fragments of shells. 



The organization of the T. conchilega, has been examined 

 by Pallas under the name of nereis conchilega. The exact- 

 ness of his description has been verified by M. de Blainville. 

 The body of this animal, of a whitish colour, with a rose- 

 tint arising fi*om the irradiation of the red colour of the 

 sanguine vessels, is rather elongated, lumbriciform, a little de- 

 pressed, nevertheless rather more convex above than below, 

 and gradually attenuating behind. Under the belly is a 

 narrow, flat, small band, which commences immediately after 

 the head, and which terminates by being narrowed and at- 

 tenuated a little beyond the middle of the body. It is divided 

 into many parallelograms, by the scissures of the segments. 



