1889.] MR. SOWERBY ON NEW SPECIES OF LAND-SHELLS. 577 



Deuterosaurus should not be identical with lirithopus, in which 

 event the latter name should stand. If the skull referred to Deute- 

 rosaurus indicate an animal of the same size as the type of Brithopus, 

 it would be evident that the incisor teeth were of larger size in 

 proportion to the limb-bones than in Titanosuchus. 



EXPLANATION OF THE PLATES. 

 Plate LIV. 



Associated vertebrae of a Theriodont from the Karoo system 

 of the Cape Colony, f nat. size. 



Fig. 1. Eight lateral aspect of two dorsal vertebras. 



2. Reversed view of the left side of an imperfect neural arch of a dorsal 



vertebra. 



3. Anterior aspect of an imperfect lumbar vertebra. 



fr.z, prezygapophysis ; pt.::, postzygapophysis ; t.-p, transverse process ; 

 r, facet for capitulum of rib. 



Plate LV. 



Fig. 1. Dorsal aspect of the restored right scapula of a Theriodont from the 

 Karoo system of the Cape. ^. a, acromial process ; i, supra-acromial 

 process ; gl, glenoidal surface. 



2. Dorsal aspect of the imperfect light scapula of Vtychosiagum 



orient ale from the Panchet beds of the Gondwana system of India. 

 \. Letters as in fig. 1. 



3. Palmar aspect of the restored left humerus belonging to the same 



individual as the scapula represented in fig. 1. i. ent.f, entepi- 

 condylar foramen ; r.e, radial condyle. 



4. Palmar aspect of the distal portion of the left humerus of Brithopus 



prisons, from the Permian of Russia. ^. ect.f, ectepicondylar 

 foramen ; other letters as in fig. 3. 



4. Descriptions of thirteen new Species of Land-Shells, with 

 a Note on BiiUmus fulminans. By G. B. Sowerby, 



r.L.s., F.Z.S. 



[Received October 3, 1889.] 

 (Plate LVI.) 



1. Helix (Geotrociius) horderi, n. sp. (Plate LVI. fig. 1.) 



H. testa anguste perforata, elata, conica, solidiuscula, oblique 

 sublilissime striata, citrina ; spira elata, apice acuta ; anfractus 

 6, convexiusculi, ultinms leviter inflatus, ad peripheriam obsolete 

 angulatus, bast convexus ; apertura lata, obliqua ; peristoma 

 late expansum et reflexum, columellari intus tuhercula parva 

 dentiformi munito, extus dilatato, complanato. 



Alt. 35, maj. diam. 30 mill. 



Hab. Nova Guinea. 



A fine yellow trochiform species presenting a character quite 

 unusual in the " Geotrochus " section, namely, a tooth-like nodule 

 on the inside of the columellar lip. 



