Mollusca.] 
NATURAL HISTORY. 
495 
the spire slig’htly raised, very near tlie edge, consisting of t^^'^o 
or three very rapidly-enlarging whorls ; the inside concave, shew- 
ing the external ribs, reddish pearly; the columella lip narrow, 
depressed, bent ; the outer lip thin, strait, or cut out ; the imperfect 
perforation about one-fifth the length of the outer lip from the end 
of the columella lip ; length two, breadth one inch and a quarter. 
This species is very distinct on account of its long form, and 
curved lower face, as well as its outer surface. 
106. Haliotis Marmora Ta, Lin, Sys. Nat. 1256. 
Icon. Martini, i. t. 14. f. 139. 
107. Padollus rubicundus, De Montforty Syst.ii. 115. 
Padollus scalaris, Leach, Zool. Misc. i. 66. 
Haliotis tricostalis, Lam. Hist. vi. 2. 218. 
Icon. De Montf.ii. t. 114. Leach, 1. c. 
This specimen, which is the largest I ever saw, measures three 
inches and a half by two and a half. It was found upon Rottnest 
Island, on the West Coast. 
PTEROPODA. 
108. Janthina PRAGiLls, Lam, Syst. Anim. 
Janthina communis, Lam. Hist. vi. 2. 206. 
Helix janthina, Lin. Sys, Nat. i. 1246. 
Icon. Lister, t. 572. f. 24. Chemn, v. t. 166. f. 1577, 1578. 
Several specimens of this shell were taken by the towing-net in 
the Indian Ocean, on the passage from the Coast of New Holland 
to Mauritius. 
109. Janthina exigua, Lam. Hist. vi. 2. 206, 
Two or three species of this shell were presented to the Museum by 
Mr. Hunter, the surgeon to the expedition; it is proved to be 
very distinct from J. fragilis, from the description of its float by 
Dr. Coates in the transactions of the Society of Natural Science 
of Philadelphia. See Annals of Philosophy for 1825, p. 385. 
