HELICOIDEA. 19 
ParypHanta, Albers, 1850. 
Distr.—New Zealand, Australia. P. Busbyi, Gray (xciii, 82). 
Shell widely umbilicated, depressed, covered by a_ thick, 
shining, coriaceous epidermis, enveloping the peristome; aper- 
ture oblique, semilunar; peristome simple. 
** (rnathophora. Mouth with jaw. Modern malacologists 
have arranged the families of this division of the Pulmonata in 
accordance with the structure of the jaw, and to a certain extent 
this accords with the arrangement by external characters—mainly 
of the shell. I adopt 
+ Holognatha. Jaw simple, without superior appendage. 
Helices, Bulimi, Cylindrellz, Pupze, Limaces, etc. 
++ Hlasmognatha. Jaw with a superior quadrangular accessory 
plate. Succinee. 
+ Holognatha. 
Includes, as shown above, most of the terrestrial pulmonates. 
A further division has been attempted according to the orna- 
mentation of the jaw, but the number of observations made 
upon this organ are not sufficiently numerous to justify a classi- 
fication in accordance therewith; particularly as the groupings 
heretofore effected are often in disaccord with obvious relations 
of the shell. 
The arrangement followed in these pages is mainly that of 
Pfeiffer’s “* Nomenclator Heliceorum Viventium,” but with some 
modifications and additions. The naked snails I have preferred 
to interpose between the Helices and Succinezx, as proposed in 
Gill’s Classification (vol. i, 266), rather than preceding the 
Helices, as in Fischer. 
I give herewith the names and descriptions of the proposed 
divisions of the Holognatha, founded upon jaw characters, with 
the principal genera which have been referred to each. Upon 
the value of these characters, see Binney’s remarks (vol. i, 261). 
I. Oxygnatha: Jaw smooth, edge cutting, often with a median 
prominence. Philomycus, Limax, Tennentia, Parmacella, Heli- 
earion, Ariophanta, Nanina, Rhysota, Vitrina, Hyalinia, Zonites 
Leucochroa, Rumnina, Clausilia : perhaps also Phania, Planispira, 
Solaropsis, Otala, Caracolla, Labyrinthus. 
Il. Aulacognatha: Jaws finely and regularly grooved, edge 
crenulated. Ena, Pupa, Discus, Vallonia; perhaps also Sagda 
and Hygromia (Fruticola . 
III. Stegognatha: Jaw finely plicated; the plications imbri- 
cated, parallel or oblique to the centre. Punctum, Bulimulus. 
IV. Odontognatha: Jaw strongly ribbed, edge toothed. Veroni- 
cella, Arion, Ariolimax, Anadenus, Pellicula, Peltella, Moreletia ?, 
Pfeifferia, Ciftonnn , Axina, Pythohelix, Helicobulimus, Cochli- 
cellus, Jacosta, Eupary pha, Eulota, Triodopsis, Trigonostoma, 
