116 



Aperture oval, ratlier small, perpendicular ; peristome con- 

 tinuous ; outer lip, its nearly semicircular curve angulated by 

 the projection of the six stouter lira? ; inner lip slightly but 

 narrowly spreading, with two or three inconspicuous callosities 

 near its junction with the pillar. 



Length, 29 ; breadth within the varices, 20 ; length of aper- 

 ture 9, of canal 7. 



Localities. — Lower beds at Muddy Creek ; blue clays at 

 Schnapper Point ; and " Gastropod bed" of the Eiver Murray 

 Cliffs, near Morgan. 



Triton Prattii was founded on immature specimens of what 

 proves to be a Itanella, belonging to the subgenus Argohuccinum, 

 characterised by an elevated spire, short beak, and the absence 

 of a posterior canal ; and I have thought it needful to des- 

 cribe and figure an adult example. The species is related to 

 B. hituhercularis, Lamarck, of the ludo-Pacific region, from 

 which it differs by being multicostated and not bi- or tritu- 

 berculated between the Yarices. 



Genus Teito:^-. 

 srK"OPSis of species. 

 I. Body whorl with a sharp keel, crenately- serrated on the 

 margin. 



Ovate ; body whorl with an anterior row of serratures. 

 Intervariceal serratures, 6 ; posterior slope cancellated. 



1. T. Abbotti. 

 Intervariceal serrp.tures, 6 ; posterior slope smooth. 



2. T. radialis. 

 Ovate ; body whorl without a second row of serratures. 



Spire whorls flat or slightly imbricating at the suture ; 



lira? smooth. 3. T. gibbus. 



Spire whorls with a narrow anterior slope ; lirae granu- 



lose. 4. T. cyphus. 



Elongate ; body whorl with an anterior row of serratures, 



intervariceal serratures 6, blunt. 5. T. Woodsii. 



Elongate ; body whorl without a second row of serratures, 



intervariceal serratures 5, cuneate. 6. T. textilis. 



II. Body whorl subquadrate, nodulate on the keels ; shell 

 ovately fusiform. 



Three rows of tubercles ; posterior rows with slender 



oblique costie. 7. T. intercostalis. 



Two rows of tubercles ; seven intervariceal tubercles on 



the posterior angulation. 8. T. annectans. 



Tubercles of the two rows confluent, four between the 



varices. 9. T. armatus. 



