262 SERPULID^. 



The dorsal surface of the abdominal portion is marked with scattered 

 black dots ; but this character is not constant. The medio-dorsal line 

 begins at the eighth segment. The posterior segments are very 

 narrow and close. 



(a) Mus. Leach. No locality. 



6. S. volutacomis, body as broad as a man's finger, moderately 

 elongated ; branchiae in two equal tufts rolled up spirally, with 3-5 

 volutions, the filaments numerous and densely ciliated ; thorax with 

 ten pairs of setigerous feet. Length 6" ; breadth 6-8'". 



Amphitrite vohitacornis, Montagu in Linn. Trans, vii. 80. tab. 7- f- 10. 



Leach in Supp. Encyclop. Brit. i. 452. pi. 26. Lam. Anim. s. Vert. 



2de edit. v. 611. Tnrt. Brit. Faun. 136. Penn. Brit. Zool. edit. 



1812, iv. 89. Stark, Elem. ii. 133. 

 Amphitrite voluticornis, Mus. Leach. 

 Sabella volutacomis, Johnston in Ann. 4" Mag. N. Hist. xvi. 449. 



Grube, Fain. Annel. 89. 



Hab. The coralline region. 



Desc. Body 5-6" long, as broad as a man's finger, depressed, 

 tapered behind, of a wood-brown colour, blotched and stained with 

 a dull blackish-brown extending over the greater part of the abdo- 

 men. Branchial tufts one-fifth or one-sixth the length of the body, 

 pale, with a dark -brown fascia at the base, the rachis of the numerous 

 filaments spotted. Collar thick and cartilaginous, four-lobed, the 

 ventral lobes largest, rich-brown, with a pale everted margin. Tho- 

 rax with ten pairs of stout setigerous feet, and as many linear curved 

 spiracles formed by the siphonate uncini ; its segments equal, 

 linear-oblong, depressed on the dorsal, and plano-convex on the ven- 

 tral side. Abdominal segments about eighty to ninety, with smaller 

 and less protuberant feet, bisected by the dorso-medial line, which 

 begins on the second segment. Tlie branch of the foot has a mam- 

 millated top, and a tuft of pencil-like bristles. There is a faint line 

 down the centre of the ventral surface, the skin of which is wrinkled 

 or roughish. Bristles in the thoracic fascicles straw-yellow, nume- 

 rous, in a cylindrical pointed brush ; the bristle is stout, vidtli a 

 cylindrical shaft bent towards the top, where it is thickened, and 

 thence tapered, like a lance, to a fine smooth sharp point ; all the 

 points connivcnt. The bristles of the abdominal feet are similar, 

 but not half so large, with a comparatively longer point. 



(a) South Devon, G. Montagu. 



{h) Falmouth. 



Of the following species I can give no account : — 



1 . Sabella unispira. 



Sabella unispira, Savign. Syst. Annel. 80. Cuv. Reg. Anim. iii. ; 

 and illustr. edit. Annel. 23. pi. 4. f. 1. Williams in Rep. Brit. As- 

 soc. 1851, 205 ; and in Ann. Sf Mag. Nat. Hist. ser. 2. xii. 396 = 

 Sabella Spallanzauii, Grube, Fam. Annel. 88. 



Introduced into our fauna on the authority of Dr. Williams. 



