TRACHEUPODA, 



Genws48.— PYRAMIDELLA — Lamarck. 



Generic Character. — Shell turrited, destitute of epidermis; 

 aperture entire, semi-ovate, the outer lip with a sharp edge ; 

 columella produced at the base, and subperforated, provided 

 with three transverse plaits. 



Pyramidella terehellum — The Wimble Pyramidella. Plate 

 XII. fig. 26. Smooth, glossy, %vhite, with reddish-brown fasciae ; 

 columella recurved ; inside of the lip smooth. One and one- 

 fourth inch long. Inhabits the American seas. 



Genus 49 TORNATELLA.— ZamarcA. 



Generic Character. — Shell convolute, ovate-cylindrical, usu- 

 ally transversely striated, and destitute of epidermis ; aperture 

 oblong, entire, with margin of the outer lip acute ; one or seve- 

 ral folds at the base of the columella. 



Tornatellafasciata. — The Banded Tornatella. Plate XII. 

 fig. 27. Covered with fine transverse striae ; spire produced, 

 apex acute ; aperture straitened, columella with one plait ; pur- 

 plish-red, with two white transverse fasciie. Inhabits the coast 

 of Britain. 



FAMILY IV. MACROSTOMA. 



Shell auriform, with the aperture very wide, and the margins 

 disunited ; without any columella or operculum. 



Genus 50. — HALIOTIS Linnaas. 



Generic Character., — Shell ear-shaped, usually depressed; 

 spire short, sometimes depressed, and nearly lateral ; aperture 

 extremely large, oblong-ovate, and entire in the adult state ; disc 

 perforated with holes, disposed in a line parallel to the left mar- 

 gin, which commences by a notch. 



Haliotis asinina. — The Assinine Haliotis. Plate XII. fig. 

 28. Internal margin very broad, inside pearly, smooth, shining, 

 iridescent, reflecting green, pink, and orange ; back clouded with 

 brown and green, and striated longitudinally, oblique ; spire yery 



