STROMBUS. SCREW-SHELL. 165 
STROMB US. S CRE W-SIIEL L . 
Shell with a single valve, spiral : aperture end¬ 
ing in a canal leaning to the left, and the outer- 
lip more or less expanded. 
♦ 1. Strombus Pes Pelecani. P electin'$ foot. Fig. 50, 51. 
Lister , pi. 865. f. 20, pi. 866. f.21. b, and pi. 1059. f. 3— 
pi. ]8 — Da Costa, pi. 7- f. 7— Donovan, pi. 4— 
Dorset Cat. pi. 15. f. 7- 
Shell tapering to a fine point, finely striate transversely, 
shite, grey, pale red or chocolate brown : spires ten, with 
a row of tubercles round each; the larger volution with 
tiro and sometimes three smaller rows, and another minute 
raw round the line of junction : aperture very narrow; the 
outer-lip much expanded into three principal angular points, 
each of them ribbed along the back by a strong line con¬ 
tinuing from the rows of tubercles, and marked with a cor¬ 
responding groove underneath ; and at the end of the third 
volution is a fourth small angular point: canal finely 
pointed, bending a little inwards, with a groove down the 
middle on the inside and corresponding rib on the outside, 
cad a sharp wing-like reflected process each side, givingit 
alanceolateappearance; inner-lip much spread and glossy; 
the margin of the outer-lip generally very thin, but some¬ 
times very thick: length two inches; breadth one and a 
When young the aperture is oval, without the expanded 
hpj which gradually dilates into its angular points. 
On most sandy coasts, v. v. 
2. Strombus costatus. Ribbed Screiv-shell. 
Da Costa , pi. 8. f. 14— Donovan , pi. 94 —Dorset Cat. 
pi 14. f. 14. 
Shell thin, tapering to a fine point, light brown to deep 
chssnut : spires ten or eleven, much rounded and tumid, 
with numerous fine longitudinal ribs, and at the bottom of 
each volution a raised circular line which is doubled on the 
larger one, becoming gradually extinct in the lesser ones 
aperture nearly orbicular; the outer-lip a little expanded 
