82 MUREX. KOCK-SHELL. 



aperture narrow-oblong, contracting a little at the canal, 

 which is moderately long and nearly straight ; outer-lip 

 thickened by a rib at the back ; inner-lip plain : length half 

 an inch ; breadth an eighth or more. 

 Western coasts, and Dublin bay. v. m. 



10. Murex Nebula. Gauze Rock-shell. 



Montagu, pi. 15. f. 6 Pennant, pi. 82. f. 7 Dorset Cat. 

 pi. 14. f/16. 



: Shell slender, tapering to a fine point : spires eight or 

 nine, scarcely raised, and separated by a very fine line, with 

 eight or nine longitudinal ribs, and crossed transversely in 

 the interstices by very fine faint lines: color yellowish- 

 white or brownish, sometimes pale rose-color, with the 

 transverse stria? white : aperture oval-oblong, narrow ; 

 outer-lip thin and plain ; inner-lip a little rugged on the 

 outside ; canal rather short, turning a little to one side : 

 length balf an inch ; breadth two tenths. 



On many fine sandy shores, v. v. 



11. Murex septangularis. Septangular Rock-shclL 



Montagu, pi. 9. f. 5 Donovan, pi. 179. f. 4. 



Shell strong, taper, pale brown, rather glossy : spires seven 

 pr eight, with seven longitudinal ribs which are scarcely 

 interrupted by the line of separation, the spaces between 

 the ribs smooth and but slightly concave, giving the shell a, 

 septangular appearance ; outer-lip thin, contracted to an 

 angle at the upper part, where the margin is a little in- 

 dented ; pillar-lip a little folded back : length half an inch, 

 pr rather more ; breadth a quarter. 



Western coasts, and Dublin bay : rare. v. m. 



12. Murex costatus. Ribbed Rock-shell. 



Pennant, pi. 82. f. 2 Da Costa, pi. 8. f. 4 Donovan, 

 pi. 91 Dorset Cat. pi. 14. f. 4. 



Shell oblong, taper, rather glossy : spires six, flat and 

 divided by the line of separation only, with seven or eight 

 elevated ribs, placed rather remotely, and not striate trans- 

 versely : color chocolate-brown,* with often white bands 3 or 

 entirely white at the base ; sometimes yellowish-white \vitii 

 & dark brown band or two : aperture very narrow, not 



much 



