Zoological Society. 123 



Altit. ab apice ad aperturse basin, 8 ; ad ultimi anfractus basin, 6 ; 

 diameter major 10 J, minor 8 a "; aperturse long. Gj, latit. 3£ lin. 



Patria, Australia meridionalis. 



Exstat in museo hon. Gruner. 



Schumacher was the first who in his ' Essai d'un nouveau Systeme 

 des habitations des vers testac£s, a Copenhague 1817/ elevated the 

 Nerita nux avellana, Chemn., to a peculiar genus, which he named 

 Amphibola. Lamarck ranged it among the Ampullarias, till Quoy and 

 Gaimard separated it, after careful examination of the animal, from 

 this genus, and instituted it the type of the genus Ampullacera. 

 It appears from this that Amphibola and Ampullacera are identical, 

 and that the first denomination has the priority. 



Our species is very like to the Amphibola avellana, but may how- 

 ever be distinguished from it by the following differences : — 1, it is 

 thicker ; 2, the whorls are lying in one plane, the spire is depressed, 

 not elevated, as with the other species ; and the last whorl, which 

 almost entirely forms the whole shell, is very much drawn down ; 

 3, it is not perforated, and although largely umbilicated, yet the 

 other smaller whorls are not visible in the umbilic ; and 4, it distin- 

 guishes itself by a very callous columella, which partly propagates 

 over the spire, following the suture at a distance of five lines. 



April 14. — William Yarrell, Esq., Vice-President, in the Chair. 



The following communications were read: " Descriptions of twenty 

 new species of Helicea, in the collection of H. Cuming, Esq.," by 

 Dr. L. PfeifFer :— 



1. Helix suturalis, Pfr. Hel. testd late umbilicatd, depressd, 

 subdiscoided, tenui, sub lente minutissime granulosa, fusco-corned ; 

 spird pland, medio subimmersd ; suturd profundd ; anfractibus 4 

 convexissimis, ultimo antice descendente ; aperturd perobliqud t 

 subcirculari ; peristomate simplice, marginibus conniventibus, dex- 

 tro recto, superne fornicato, columellari subrecedente, arcuato, 

 basalique breviter reflexo. 



Diam. 10, alt. 4 mill. 



Found at Honduras under decayed leaves by Mr. Dyson. 



Nearly allied to H. Nystiana. 



2. Helix candaharica, Pfr. Hel. testd umbilicatd, orbiculato- 

 convexiusculd, oblique striatuld, nitiduld,fuscescenti-albidd,fasciis 

 angustis, maculose interruptis, nigricantibus et rufis ornatd ; spird 

 vix elevatd, apice nitido, corneo ; anfractibus 5 convexiusculis, 

 ultimo antice non descendente ; umbilico infundibuliformi, anfrac- 

 tuum penultimum late monstrante, medio angustissimo ; aperturd 

 obliqud, lunato-ovali ; peristomate acuto, intus subremote labiato, 

 marginibus conniventibus, columellari vix dilatato. 



Diam. 16, alt. 1\ mill. 



From Candahar, East Indies (Benson). 



3. Helix aulacospira, Pfr. Hel. testd late umbilicatd, depressd, 

 discoided, tenui, irregulariter et leviter malleatd, lineis impressis, 

 concentricis, confertis regulariter sulcatd, lutescenti-corned ; spird 



KS 



