SERPULA. 1073 



spiRORBis. 8. Shell regular, spiral, and orbicular ; 

 whirls slightly grooved above and Mithin, 

 and gradually tapering to a point. 



Serpula spirorbis. Linnaus St/st. Nat. p. 1265. Martini, 



i. p. 59. t. 3. f.Q.1, A and B. Pennant ZooL iv. p. 145. 



t.gi. f. 155. Da Costa Brit. Conch, p. 22. t. 2. f. 11. 



Schroeter Einl. ii. p. 538. Fahricius Fauna Groenl. 



p. 377. Mul/er Zool. Dan. iii. p. 8. t. 86. f. 1 to 6. 



Gmelin, p. 3740. Donovan, i. t. Q. Montagu Test. 



p. 498. Maton and Racket, in Lin. Trans, viii. p. 241. 



Dorset Cat. p. 59. t. 22. f. U. Brookes's Introd. 



p. 142. t. 9. f. 134. 

 Spirorbis nautiloides. Lamarck St/st. des Anim. p. 326. 

 Lister Conch, t. 55S. f. 5. Petiver Gaz. t. 35. f. 8. Gual- 



ter, t. 10. f. O. Ginanni Adr. ii. 1. 1. f. 8. 

 Variety. With the whirls reversed. 



Chemnitz, ix. part ]. p. 151. t. Il6. f. 999- 

 Inhabits the sea on Fuci and Zoophytes, on all the coasts of 



Europe. 

 Shell about a line in diameter, round, white, smooth, and opake, 

 consisting of two whirls gradually and regularly coiling to a 

 point, like some of the depressed Helices. 



TRiQUETRA. 9. Shell creeping, flexuose, and three- 

 sided. 



Serpula triquetra. Linnaus S]/st. Nat. p. 1265. Martini, 

 i. p. 68. t. 3. f. 25. Pennant Zool. iv. p. 146. t. 91. 

 f. 157. Da Costa Brit. Conch, p. 20. t.2. f.9. Born 

 Mus. p. 436. t. 18. f. 14. Schroeter Einl. ii. p. 540. 

 Gmelin, p. 3740. Dorset Cat. p. 59- t. 22. f. 9- Dono- 

 van, iii. t. 95. Montagii Test. p. 511. Maton and 

 Racket, in Lin. Trans, viii. p. 244. 

 Gualter, 1. 10. f. P. Ellis's Corallines, t. 38. f. 3. 

 Common on the shores of Europe and America, on shells, 



stones, wood, and Algas. 

 Shell strong, opake, wrinkled, variously twisted, and sometimes 

 nearly straight ; it has a dorsal elevated ridge, and the base 

 spreads so as to give it a triangular appearance. Mr. Mon- 

 tagu has remarked, that the funnel-shaped proboscis of the 

 inhabiting Terebella is single, and therein differs from that 

 of S. vermicularis, which is double. 



INTRICATA. 10. Shell filiform, rough, taper, and 

 flexuose. 



