158 HELICOLIMAX. 



which have the apex distinctly and prominently bent forwards. 

 Ex. P. pellucida, fig. 230. 



HELENIS. Montf. A genus of microscopic Foraminifera. 



HELICELLA. Fer. One of the sub-genera into which De 

 Ferussac has divided the genus Helix, consisting of depressed 

 species with large umbilicus, such as Helix Algira, fig. 279. 

 Gonites Montf. 



HELICIFORM. Shaped like shells of the genus Helix. 



HELICIGONA. One of De Ferussac's sub-genera of the genus 

 Helix, consisting of angulated species, such as Carocolla 

 Lamarckii, fig. 277. 



HELICINA. Lam. Fam. Colimacea, Lam. Ellipsostomata, Bl. 

 — Descr. Globose, compressed, or angulated, generally light and 

 thin ; aperture trigonal or semilunar ; outer lip thickened and 

 generally more or less reflected ; inner lip spread over the body 

 whorl, frequently callous near the columella, which is short, and 

 terminates in a notch, angle, or slight callosity.— Obs. This genus 

 of land shells, distinguished from the genus Helix, by having an 

 operculum and a thickened columellar lip, differs also from 

 Cyclostoma in having the aperture semicircular or angular, the 

 peritreme discontinuous and the operculum concentric. These 

 shells are generally small in size, and simple in form. Lamarck 

 describes only three or four species. Mr. Gray described some 

 others in the Zoological Journal, and in a work shortly to be 

 published by the author, a monograph of the genus will contain 

 descriptions and figures of at least 60 distinct species ; some of 

 which have been lately brought to this country by Mr. Cuming 

 from the Philippine Islands. They mostly belong to tropical 

 climates. 



HELICITES. Bl. Part of the genus Nummtjlites, Lam. Rota- 

 lites and Egeon, Montf. 



HELICOGENA. Fer. A sub-genus of Helix, consisting of species, 

 which, like the common garden snail, fig. 268, are globose and 

 simple in form. 



HELICOLIMAX. Fer. Vitrina, Drap. H. Pellucida, fig. 263. 





