tragments of bivalves (chiefly Pectens) which are irregu- 
larly disposed, often imbricated, but invariably with the 
concave side outwards, which leaves a narrow perfora- 
tion. Torcross, Devonshire, in deep water. 
TRIBE.—SERPULACE. 
Tube solid and calcareous. 
GrENus.—SPIRORBIS. 
Tube testaceous, twisted into a spiral discoid orb ; 
lower surface flat and affixed. 
S. NautitoipEs. Lam. 1.—SeRpuLa SpiRoRzis. 
Lin. 1265.—Last. t. 553. f. 5.—Mart. f. 21. A. B. 
Pen. 4. p. 145. t. 21. f. 155.—Da. Cost. t. 2. f. 
11.—WMont. p. 498. -—D. p. 1073.—Turt. D. p. 149. 
Don. t. 9.—Opaque, white, with three or four regular 
lateral whorls, rounded on the upper part and a little 
wrinkled; umbilicated in the centre; base flat, spread- 
ing. Variety. With the mouth erect and sometimes a 
whorl or two turning a little spirally upwards. #4. 
Excessively common on lobsters, Se. 
S. Sprrirtum. Lam. 2.—Serputa. S. Lin. 1264. 
Turt. D. p.150.—Dor. Cat.t. 19. f. 27.—D. p. 1072 
Mont. p. 499.—Lin. T. 8. p. 240.—Reversed var.— 
Sinistorsa. Mont. p. 504.—Walk. f. 134.—Glossy 
white, semi-transparent, orbicular,regular ; whorls two or 
three, slightly wrinkled, and mostly placed laterally, the 
As 
