452 Dr. Johnston’s Index to the British Annelides. 
Vermiculum retortum, Mont. Test. Brit. 524. 
Spirorbis retorta, Fleming in Edin. Phil. Journ. xii. 245. 
10. S. annulus. 
Spirorbis annulus, Brown’s Illust. pl. 1. fig. 44. 
11. S. heterocliticus. 
Spirorbis heterocliticus, Brown’s Illust. pl. 1. fig. 57. 
12. S. striatulus. 
Spirorbis striatulus, Brown’s Illust. pl. 1. fig. 59. 
**Heterodisca, Flem. Phil. Zool. ii. 602. 
13. S. heterostrophus. 
Serpula heterostropha, Mont. Test. Brit. 503. Turt. Brit. Faun. 201. 
Dillw. Rec. Sh. 1075. Penn. Brit. Zool. iv. 359. ‘Turt. Conch. 
Dict. 151. 
Spirorbis heterostrophus, Fleming in Edin. Encyclop. vii. 68. pl. 205. 
fig. ]. Brown’s Illust. pl. 1. fig. 55. 
Heterodisca heterostropha, Fleming in Edin. Phil. Journ. xii. 247. 
14. S. minutus. 
Serpula minuta, Mont. Test. Brit. 505. Turt. Brit. Faun. 200. 
Dillw. Rec. Sh. 1072. Penn. Br. Zool. iv. 359. Turt. Conch. 
Dict. 150. 
Spirorbis minutus, Fleming in Edin. Encyclop. vii. 68. 
Heterodisca minuta, Fleming in Edin. Phil. Journ. xi. 247. 
15. S. conicus. 
Spirorbis conicus, Fleming in Edin. Encyclop. vii. 68. pl. 205. fig. 3. 
Brown’s Illust. pl. 1. fig. 58. 
Heterodisca conica, Fleming in Edin. Phil. Journ. xii. 247. 
16. S. lucidus. 
Serpula lucida, Mont. Test. Brit. 506. Laskey in Wern. Mem. i. 
412. Brown in ibid. ii. 534. Turt. Br. Faun. 201. Penn. Br. 
Zool. iv. 360. Dillw. Rec. Sh. 1075. Turt. Conch. Dict. 151. 
Serpula reflexa, Adams in Linn. Trans. 
Spirorbis lucidus, Fleming in Edin. Encyclop. vii. 68. Brown’s 
Illust. p. 1. fig. 56, 60. 
Serpula sinistrorsa, Mont. Test. Brit. 504. 
Heterodisca lucida, Fleming in Edin. Phil. Journ. xii. 247. 
Obs. The Serpula sinistrorsa is made a variety of Serp. spirillum by 
Turton, Dillwyn and Pennant. 
17. S. reversus. 
Serpula reversa, Mont. Test. Brit.508. Turt. Br. Faun. 201. Penn 
Brit. Zool. iv. 361. 
Spirorbis reversus, Fleming in Edin. Encyclop. vii. 69. Brown’s 
Illust. pl. 1. fig. 52. 
Heterodisca reversa, Fleming in Edin. Phil. Journ. xii. 248. 
Ods. Dillwyn and Turton make this a variety of their Serpula ver- 
micularis. 
