84 Messrs. J. C. Melvill and J. H. Ponsonby on 



of Amplnoxus in the series of higher animals. Nevertheless, 

 that it constitutes an actual transition between the two great 

 groups of the animal kingdom can be asserted of it equally as 

 little as of an Orthonectid or of Triclioplax ; for indeed we 

 have here isolated links before us for which we cannot find a 

 place in our system, beautifully and ingeniously constructed 

 though it is, and which tend to prove how little Nature is 

 amenable to a dogmatic treatment on our part, a treatment 

 which unfortunately appears to take the upper hand too much 

 in the biological sciences, and which would gladly exclude 

 everything which does not fit into its narrow frames. 



XIII. — Descriptions of Seven new Species of Terrestrial 

 Mollusca from South Africa. By James Cosmo Melvill, 

 M.A., F.L.S., and John Hexky Ponsonby, F.Z.S. 



[Plates IV. & VI.] 



1. Helix [Pella) trichosteiroma^ sp. n. 

 (PI. IV. fig. 9.) 



JI. testa angustissime sed profunde urabilicata, comeo-fusca, con- 

 vexiuscula, sublaevi, longitudinaliter oblique tenuistriata, undique 

 lirulis spiralibus minutissime decussata : anfractibus quiuque, 

 ultimo in medio cariuato, carina capillis brevibus accincta ; aper- 

 tura lunari-ovata ; peristomate simplici ad marginem columellarem 

 reflexo. 



Long. 5-50, lat. 7*50 mill. 



Hob. Port Elizabeth, S. Africa. 



Judging from the description of Helix petrohia (Benson), 

 recorded from High Constantia, Cape of Good Hope, but of 

 which we have not been able to examine the type, the species 

 under discussion would seem to difier chiefly in the acutely 

 angled keel, fringed Avith regular, short, epidermal hairs, also 

 in the form being more convex, colour dull brown, with no 

 fulvous tinge, and other minor distinctions. 



2. Helix {Pella) epetrima, sp. n. (PI. IV. fig. 3.) 



//. testa anguste umbilicata, depressa, tenui, cornea, subpellucida, 

 undique confertim striatula, striis obliquis regularibus, spira de- 

 ])resso-convexa ; anfractibus quatuor, convcxiusculis, ad suturas 

 imprcssis, ultimo aufractu rapide accroscento ; apertura luuuri ; 



