STPxOMBUS. SCREff'-SHELL. 16,5 



STROMBUS. SCREW-SHELL. 



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 Pelccani. Pelocansfoot. Fig. 50, 51. 

 Lister, pi. 8f)5. f. 20, pi. 866. f. 21. b, and pi. 1059.f. 3 



Pennant, pi. 78 Da Costa, pi. 7- f 7 Donovan, pi. 4 

 Dorset Cat. pi. 15. f. 7. 



Shell tapering to a fine point, finely striate transversely^ 

 white, grey, pale red or chocolate brown : spires ten, with 

 a row of tubercles round each ; the larger volution with 

 two and sometimes three smaller rows, and another minute 

 .row 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, 

 and a sharp wing-like reflected process each side, giving it 

 a lanceolate appearance; inner-lip much spread and glossy -, 

 the margin of the outer-lip generally very thin, but some- 

 times very thick : length two inches j breadth one and a 

 half. 



When young the aperture is oval, without the expanded 

 lip, which gradually dilates into its angular points. 



On most sandy coasts, v. v. 



2. Strombus costatus. Ribbed Screw-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 

 chesnut : 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 



and 



