122 



Last whorl ventricose, narrowly truncated and bicarinated 

 at the periphery, with four intervariceal nodulations, those of 

 the anterior row confluent w^ith the corresponding ones behind, 

 and continued backward as oblique, broad undulations, becom- 

 ing evanescent before reaching the suture. Base with a strong 

 encircling thread, equidistant with the two carinations. 



Aperture oval ; outer lin smooth within, flatly and narrowly 

 expanded, continuous with the smooth inner lip which is 

 broadly reflected over the columella ; aperture contracted in 

 front by a columella fold, and a stout ridge opposed to it on 

 the outer lip. Beak with a very broad depressed base, twisted 

 and reverted. 



Length, 41 ; breadth, 24 ; length of aperture, 13 ; of canal, 

 12. 



Locality. — In a well sinking in the Murray Desert. 



This species is not much unlike T. annectans, but differs by the- 

 shape and fewness of the intervariceal nodulations. 



10. Triton ovoideus, spec. nov. Plate ix., fig. 4. 



Shell ovate, with a short, broad, conical spire ; apex obtuse ? 

 Whorls four (incomplete), rounded, slightly angled at the 

 anterior suture, and furnished at the angulation with six small 

 rounded intervariceal nodulations ; encircled throughout with 

 flattened beaded ridges, alternating with very narrow simple 

 threads. Varices six, at a^bout four-fifths of a whorl, rounded, 

 convex axially, and ornamented as the rest of the surface. 



Columella arched, furnished with an obliquely axial, elon- 

 gate callosity at the posterior angle, and with tooth-like ridges 

 at the front. 



Canal very short, much bent to the right, and slightly re- 

 verted. Outer lip thickened, with seven strong denticulations 

 within, the anterior one much larger than the rest. 



Length, 23 (estimated, 24" 5) ; breadth, 14; length of aper- 

 ture and canal, 14. 



Locality. — Upper beds at Muddy Creek (J". Bennant l) . 



A species exceedingly like T. Bassi, Angas, but conspicuously 

 distinct by its broader and fewer (about half the number) lirae, 

 and consequently by the fewer and stouter denticulations on the 

 outer lip; moreover, the spire w^horls are more angular, the 

 nodulations smaller ; the aperture is oblique, and the canal 

 more twisted. 



11. Triton tumulosus, spec. nov. Plate v., fig. 2. 



Shell ovately conical, with a moderately high distorted spire 



of subgradated w^horls. Apex of two polished whorls ; the- 



anterior one is high, bicarinated, and transversely striated ;, 



the posterior one, encircling a shallow concavity, at first sud- 



