SERPULA. 271 



Heterodisca reversa, Fleming in Edinb. Phil. Journ. xii. 248. 

 Eupomatus pectinatus?, Philippi in Ann, ^ Mag. Nat. Hist. xiv. 160* 

 pi. 3. f. 2. 



Hab. The coralline region. Common. 



Obs. The shell is adherent, dull white, wrinkled, flexuose, and 

 inclined to become spiral, especially behind ; and " it is remarkable, 

 in a species so irregular in growth, that the aperture should almost 

 invariably turn in the reversed direction. Diameter at the large end 

 one-tenth of an inch." Montagu. — The branchial tufts are equal, 

 and the filaments have a naked setaceous point. The lower funnel 

 of the operculum is of a vitreous white colour, with the marginal 

 serratures continued as grooves down the outside for a short distance. 

 It would make an elegant pattern for a wine-glass ; and the entire 

 organ for a cornucopia. The upper operculum issues from the 

 centre of the inferior, is more membranous and of a yellowish-brown 

 colour, and armed around the rim with a series of about twenty 

 stout, erect, spinous processes. Philippi says, that, in his species, 

 there were only twelve of these thorny processes which had three 

 spines on each side, opposite to each other ; but in our specimens 

 there was no certain number, varying from five to seven, and they 

 were either opposite or alternate, or sometimes there would be a 

 pair. 



(«) Aberystwith, J. Henslow, 



4. S. Berkeleii, branchiae with about six filaments in each tuft ; 

 operculum funnel-shaped, smooth, with an entire margin. — Tube 

 triquetrous, with a sharp dorsal keel. 



Hab. The coralline region, attached to old shells. Rare. 



Obs, The animal is about 1^" long. The branchiae are in two 

 equal tufts, the filaments divided to the bottom, beautifully cihated 

 as usual, with a naked setaceous point. The abortive tentaculum is 

 setaceous ; and the other forms a short stalk to a perfectly smooth 

 funnel-shaped operculum. — The tube is adherent by a flattened base 

 throughout, triquetrous, flexuose, of a solid close texture and white 

 colour, with a single dorsal keel. 



{a) Berwick Bay, Br. Johnston, 



5. S. conica, branchiae with many filaments in each tuft; oper- 

 culum conical, seated in the axil of two soft processes prolonged on 

 each side from the top of the short stalk.— Tube adherent, cylin- 

 drical and wrinkled, with a trace of a dorsal keel, the aperture 

 circular. Length 1-1 1^". 



Serpula triquetra, var. 3, Mont. Test. Brit. Supp. 157. 

 Vermilia conica, Fleming in Edinb. Phil. Journ. xii. 243. 

 Patella extinctorium, Turt. Conch. Diet. 138, operculum. 



