APLTSIA. 71 



turn. The outer lip, sometimes called the labrum, is on the op- 

 posite side, or the farthest from the axis. If the edges of the 

 inner and outer lips unite all round, they are described as com- 

 posing the peritreme. In fig. 318, the aperture is marked by 

 the letter a. 



APHEODITE. Lea. (from AfpodiTri, Grreek name of Venus.) 

 AcAEDO, Swains. A genus composed of Caeditim Grroenlandi- 

 cum, Auct. fig. 123,* and other similar species of Cardium, the 

 teeth of which are either wholly wanting, or very indistinct. 

 Northern Ocean. PI. vi. fig. 123.* 



APICIAL. Belonging to the apex. The apicial extremity of the 

 aperture of a univalve shell, is that which is nearest to the apex 

 of the spire. 



APLEXA. Pleming. 1824. A genus composed of Physa Hypno- 

 rum, Drap. &c. and described as having the inner lip simple, 

 and not spread over the body whorl. 



APLODOIN". Eafinesque. A genus proposed to be established 

 at the expense of the genus Helix, but upon what grounds does 

 not appear from the imperfect description, which is unaccom- 

 panied by a figure. 



APLUSTETJM. Schum. A genus formed for the reception of 

 some species of BtjlIiA which have the spire uncovered. Ex. 

 Bulla Thalassiarchi, fig. 289. Three species are enumerated 

 by Mr. Adams in his Monograph of the Bullidse in Sowerby's 

 Thesaurus, PI. xi. 



APLTSIA. G-mel. 1790. («, without ; nXvw, to wash.) Fam. 

 Laplysiens, Lam. Aplysiana, Bl. — Bescr. Horny, transparent, 

 clypeiform, or shield-shaped, placed horizontally on the back of 

 the animal, with its convex side uppermost : apex slightly in- 

 curved. — Obs. The animal producing this shell has derived its 

 name from the purplish liquor which it exudes, when disturbed. 

 In contour, it has been fancied to present a certain likeness to a 

 hare crouching, and on this account was called Lepus marinus, 

 or sea hare, by the ancients. The sheU bears a strong resem- 

 blance to DolabeUa, which, however, is much thicker, and more 



