SERPULA. CREEPER. 15 1 
versely especially in the furrows between the ribs : aper¬ 
ture round: diameter the eighth of an inch. 
Variety. With two brown circular bands on the top be¬ 
tween the ribs: about half the size, and found among the 
roots of Fuci .and Corallines. 
On stones and shells, v. v. 
5. Serpula heterostropha. Irregular Creeper. 
Montagu, p. 503. no. 7- 
Shell strong, dull dirty white: spires three, reversed. 
Tilth three ribs running circularly round them, and roughly 
wrinkled transverselythe base Oat and somewhat spread¬ 
ing. It differs from the last, in having the volutions in a 
contrary direction, the base a little spread, and the ribs 
cot so much raised : it is also about half the size only. 
On shells, and sea-weed. v. v. 
6 . Serpula carinata. Ridged Creeper. 
Montagu, p. 502. no. 4. 
Shell dull white, opake, regular : spires three or four, 
the outer one with a keel-like ridge on the top, perforated 
in the middle, a little spreading at the base: aperture 
nearly circular. It differs from S. spirorbis in the angular 
shape of the outer volution and from S, triquetra in being 
regularly spiral: diameter half a line. 
On old shells, v. V * 
/. Serpula cormgata. Rough Creeper, 
Montagu, p. 502. no. 5. 
Shell white, rather glossy, strong, regular: spires two 
or three, rough with transverse wrinkles, perforated in the 
middle, and very little spreading at the base. It differs 
from S, Spirillum in not exposing so much of the interior 
volutions, a small portion of the second only being visible; 
diameter the eighth of an inch. 
On schistose rocks, v.v. 
8 , Serpula lueida. Glassy Creeper, 
Serpula reflexa. Linn. Trans, v. pi. 1. f. 31, 32. 
Shell white, transparent, quite smooth and with a glassy 
lustre: spires two ox three, reversed, sometimes placed 
laterally. 
