OF MOLLUSCA. 



51 



8. Amaura. 

 " Animal allied to Natica ; foot small, compact, without any pos- 

 terior lobe ; the front lobe deeply sinuated. Eyes subcutaneous, 

 situated at the internal base of the lobe. Operculum terminal, fcw- 

 whorled, horny, thin. Shell ovate, imperforate, small ; spire pro- 

 duced ; mouth reversed pear-shaped, about half the length of the 

 shell."— Mailer, Moll. Grcenl. 1842, 7. 



1 . A. Candida, I. c. 



Fam. XIX. NERITOPSIDiE. 



Animal unknown. Shell semiovate, solid, white, spirally ribbed, 

 nodulose, imperforated. Mouth ovate; inner lip rather flattened, 

 transverse, with a broad central notch. Operculum ? 



1. Neritopsts. 

 Character of family. 

 1. N. radula. 



E. Ptenoglossa. Teeth in numerous longitudinal series. 



* Mantle and mouth of shell angular in front and rather siphoned. 

 Operculum none (or vesicular V). 



Fam. XX. IANTHINID.E. 



Head small, with a short inflated retractile proboscis. Teeth in 

 numerous diverging transverse series (fig. 29). Eyes none. Ten- 

 tacula bifid. Gills double, one with two ranges of lamellae and with 



Fig. 29.— Teeth oilanthinafragilis. 



rudimentary mucous filaments. Foot small, flat, with a vesicular 

 appendage on the hinder part of the under side. Body and shell 

 spiral. Hermaphrodite, self-impregnating? Eggs contained in a 

 vesicular mass attached to the foot, like Capulus. 



1. Ianthina. 



Mantle lax, swelling beyond the edge of the shell, and forming an 

 incipient canal. Tentacles short, conical, pointed, deeply cloven. 

 Eyes obsolete. Foot truncated in front. — Clark, Ann. §• Mag. N. 

 H. 1853, 47. 



