AMICULA. Gl 



from the body whorl, which is elastic. Ex. Bulla fragilis, 

 fig. 247. 



AL^EA. Jeffrey's. A genus of minute land shells, resembling 

 Vertigo, but separated because they are dextral, while Vertigo is 

 sinistral. Ex. fig. 292. A. marginsta, Pupa raarginata, Drap. 

 found in marshy ground, roots of trees, moss, &c. Britain and 

 Southern and Central Europe. 



ALASMODON. Say. A division of the genus Unio, Auct. con- 

 sisting of those species which have cardinal, but no lateral 

 teeth. Ex. A. complanatus, fig. 141. North America and Europe. 



ALATiE. Lam. A family of the order Trachelipoda, Lam. con- 

 taining the following genera which may be thus distinguished. 



1. RiOstellaria. Sinus close to the canal ; including Hip- 

 pochrenes, and Apoi'rhais, Fig. 402 to 404. 



2. Strombtjs. Sinus not close to the canal. Fig. 406. 



3. Pteroceras. Same, digitated. Fig. 405. 



ALATED. (From Ala, a wing.) Winged, a term applied to shells, 

 when any portion of them is spread out in any direction, as in 

 fig. 403. Hippochrenes, Montf. and fig. 147, Unio Alatus. 



ALCADIA. Gray? (B. M. Syn. p. 134) Helicinse which have a 

 notch in the aperture. . A distinction which it is impossible to 

 maintain. See Helicina. 



ALATUS. Humphrey. Strombtjs, Auct. 



ALECTRION. Montf. Buccinum Papillosum, Auct. fig. 422. 



ALEPAS. Rang. A genus of Pedunculated Cirripedes without a shell. 



ALVEOLINA. D'Orbigny. A genus of microscopic Foraminifera. 



AMALTHUS. Montf. A. margaritaceus, Montf. is a species of 

 Ammonites described as very flat, keeled, with an angular aper- 

 ture. It belongs to the family Ammonacea, Lam. 



AMARULA ? A genus composed of Melania Amarula, 



Auct. and similar species. 



AMBIGU^E. Lam. The fourth section of the order Conchifera 

 Dimyaria, containing the family Chamacea, fig. 153 to 155. 



AMICULA. A genus formed for the reception of Chiton amicu- 

 latus, Auct. the valves of which are covered by an integument; so 

 as to be completely hidden externally. 



