242 TEREBELLID^. 



The Nais auricularis of Bosc {Hist. nat. Vers, i. 240. pi. 7. f. 9) 

 may be the abdominal portion of a small Vemisia. 



This is not the TerebeUa conchileya of Pallas, nor the T. cristata 

 of Miiller, nor do I find it described excepting by Dalyell. The worm 

 is of a pale-reddish translucent colour, with numerous long tenta- 

 cula, which are prettily speckled with red or scarlet dots. The 

 head is defined and encircled by a membranous collar divided into 

 two lobes by a deep sinus on the dorsum, and behind this sinus 

 there are two to four specks, which may be eyes. The branchiae 

 are in a single pair, tufted ; the filaments tapered, and with dark 

 apices. The anterior segments are short ; the following are about 

 as long as broad, and they lengthen backwards so as to become 

 three times as long as their diameter, but they do not differ in any 

 peculiarity. Every one has a pair of setigerous as well as of unci- 

 nated feet ; and the figure formed by the uncini is a short ellipsis. 

 The abdominal portion is often spotted like the tentacula with scat- 

 tered red dots. On the abdominal segments they are raised on 

 prominent obtuse papillae, one on each side of the posterior line of 

 the segment. Caudal segments very short. Abdominal band 

 smooth. Dorsum smooth and even. The bristles and uncini offer 

 no peculiarity. 



(«) Berwick Bay — the tube on Venus islandica. 



{U) The tube on Pecten maxivms. 



(c) Berwick Bay : the animal only, Dr. Johnston. 



(d) South Devon, George Montagu. 



(e) Berwick Bay, Dr. Johnston. 

 (/) Berwick Bay, Dr. Johnston. 



(ff) The case and tenant on Cardiiun echinatum. 



(A) A case overgrown with Sertidarice, Berwick Bay, Dr. Johnston. 



40. TEREBELLIDES. 



Terebellides, Sars, Beskriv. 48 (1835). Grube, Fam. Annel.Sl. Ed- 

 wards in Lam. An. s. Vert. 2de edit. v. 608. 



Char. Body vermiform : branchiae consisting of four vertical pec- 

 tinated leaf-like lobes supported on a common stalk, and placed on 

 the back in front : mouth with numerous capillary tentacula. 



1 . T. Strcemii. 



Terebellides Strcemii, Sars, Beskrivelser, 4^. pi. 13. f. 31. 

 TerebeUa pecten, Dalyell, Pow. Creat. ii. 208. \± 26. f. 9. 



Hab. Shores of Scotland, Dalyell. 



Desc. " Length 4 lines, with long black bristles, forming pencils 

 down the sides. A wide thin lip in front. Tentacula about twenty. 

 Branchiae peculiar. A stout fleshy stem sustains the whole, Avhich 

 consists of four members, two larger, two smaller, each composed of 

 a rib with prolonged cylindrical and somewhat extensile subordinate 



