SPIRORBIS. 
GENERIC CHARACTER: Tube testaceous, twisted into 
a round flattened spire; lower surface flat, and fixed to 
another body. Operculum pedunculated, flat at the top, 
situate between the branchiae. 
* SP. NAUTILOIDES. Serpnla Spirorhis. Turt. Lin. 
Pen. Brit. Zo., vol. 4, pi. 91, fig. 155. Slew. Elem., vol. 
2, p. 4-22. Mont. Test. Brit., vol. 2, p. 498. Common on 
stones, shells and other substances. 
SPIRILLUM. Serpula Sp. Turt. Lin. Stew. Elem., 
*ol. 2, p. 421. Mont. Test. Brit., vol. 2, p. 499. 
Montagu says, this species has much the habit of the pre- 
J-eding, but is distinguished from it by its glossy appearance, 
being more eylindrie, and not spreading at the base. Cotn- 
* n °n on shells, stones and other substances. 
SP. GRANULATA. Serpula G. and Sulcata. Turt. 
Lin. Mont. Test. Brit., vol. 2, p. 500. Common on rocks 
a nd stones. 
S P. CAR1NATA. Serpula C. Mont. Test. Brit., vol. 2, 
p. 502. It is distinguished from Sp. Nautiloides by the 
a «gulated shape of the outer whirl, which is formed like 
that of Vermilia Triquetra, but regularly spiral. Not 
* Uncommon on shells. 
S P. CORRUGATA. Serpula C. Mont. Test. Brit., 
» v °l. 2, p. 502. Not uncommon. 
S P- MINUTA. Serpula M. Mont, Test. Brit., vol. 2, 
P* 505. 
. Montagu observes, this very minute species is also an 
le teroclitical shell, and not easily distinguished from S. He- 
^°stropha, except by its inferior size, and habits ; this 
j b'cts only the Corallina officinalis, frequently in abundance, 
^h on stalks and branches. 
LUCIDA. Serpula lteflexa and S. Yitrea. Turt. Lin. 
®* L. Mont. Test. Brit., vol. 2, p. 507. 
Montagu says, it is peculiar to some species of Sertularia, 
^Pecially S, Abietina and S. Argentea; and on them not 
Common. 
Q SERPULA. 
^ENerjc CHARACTER: Tube testaceous, creeping, 
tapering, irregularly twisted, sometimes slightly keeled; 
* * e d to another body. 
,• VERMICULARIS. S. Intricata. Turt. Lin. Pen. 
" r *t. Zo., vol. 4, pi. 91, fig* misplaced, 158. Stew. Eletn., 
* o o1, -< P- 422. Mont. Test. Brit., vol. 2, p. 509. Common. 
TUBULARIA. Mont. Test. Brit., vol. 2, p. 513. The 
a 'ost beautiful, and commonly the largest, of the British 
* ar pula!8B, It comes from deep water, and is scarcely 
c °mmoti. 
