UNIVALVES. 



PLATE XXVIII. 



Genus. SCALARIA. 



Character. Shell spiral, pyramidal, having no beak, pointed, covered with cir- 

 cular ribs, detached, projecting, placed spirally, ascending to the top, the ribs being 

 different in colour from the rest of the shell ; mouth round and labiated, with a circu- 

 lar and reflected edge of the same colour as the ribs. 



Species. 



No. 1. Scalaria maroccana. Shell blue, marked longitudinally with white ribs, 

 and streaked transversely with brown marks ; mouth brown, and opening at 

 the top into a small channel. This curious specimen is found on the coast 

 of Barbary. 



No. 2. Scalaria brunella. Shell of a rich brown, variegated with white ribs ; 

 the mouth invested with a projecting denticle upon the side of the columella. 

 Found on the Coast of Coromandel. 



No. 3. Scalaria clathrus. Shell pale ferruginous brown, slightly streaked with 

 purple; mouth round and smooth. A native of the British coasts. 



No. 4. 5. Scalaria disjuncta, or royal ventletrap. Shell of a pale purple, 

 richly ornamented with white ribs, and having all the folds of the spire de- 

 tached and separate from each other, forming thereby a singular pheno- 

 menon, and an exception to all other known shells. It is chiefly found in 

 the Eastern Seas. 



No. 6. Scalaria variegata. Shell red and yellow, the folds of the spire varying 

 in colour, the first being red, the others yellow. Found on the coasts of 

 the Mediterranean Sea. 



No. 7. Scalaria pallas. Shell blue and white, and first discovered in the Baltic 

 Sea by Professor Pallas ; the ribs are more close and numerous than in the 

 other species, and give altogether a pleasing appearance to the intricacy of 

 its form. 



No. 8. Scalaria greenlandica. Shell of a pale brown invested with thong- 

 shaped ribs ; the four upper folds of the spire smooth ; the mouth round. A 

 native of Greenland. 



REMARKS. 



The genus Scalaria takes its name from the fancied resemblance which it has to a ladder. It 

 has a distant similitude to the genus Turbo of Linnaeus, but is of a much more compound 

 and intricate structure, for which reason 1 have adopted the opinions of the modern French 

 Naturalists in placing it as a distinct genus. These shells are very rare, and have sometimes 

 been sold by auction at ^50. each, though now much more common than formerly, owing, 

 perhaps, to the great care taken of those which have been procured at various times. As a 

 pattern of the curious workmanship and variety of Nature they exhibit a most elegant 

 model of grace and lightness. 



