156 



slopes, b}^ its more sliarply bent attenuated beak, by the pos- 

 terior deuticles on the columella, audby its larger and different 

 pullus. 



5. Peristernia altifrons, spec. nov. Plate x., fig. 1. 



Shell fusiform, stout (apex wanting); whorls five, rapidly 

 -enlarging ; posterior whorls shouldered, the posterior slope 

 ^ery narrow and at first inclined inwards, ornamented by equal 

 lir?e and cancellated by straight striae ; with increase of growth 

 the whorls become increasingly convex and plicated. Last 

 whorl tumid in the middle, with seven narrov\% somewhat 

 humpy, curved plications on the medial region, spirally lirate. 

 Lirffi equidistant, about 20 on the penultimate whorl, with wide 

 interspaces, but on the medial and anterior areas and on the 

 base of the last whorl they are alternately large and small. 



Aperture oval ; columella with a strong fold at the front, 

 decurrent on the canal ; canal stout, apparently of moderate 

 length, curved to the left and reverted. 



Length, incomplete, 38 ; breadth, 18 ; aperture, length 15, 

 width 7. 



Locality. — G-astropod-bed of the Eiver Murray Cliffs. 



6. Peristernia Aldingensis, spec. nov. Plate viii., fig. 8a, 8&. 



Shell fusiform, stout, with a high conical spire, ending in a 

 small blunt mammilate apex of two and a half whorls ; for 

 about a third of a whorl from the junction with the spire the 

 surface is furnished with linear transverse plications. 



"Whorls eight and a half, increasing somewhat rapidly, 

 convex, with seven large rounded oblique ribs on each whorl, 

 w^hich die out on the base of the last whorl, separated by broad 

 open furrows. Surface scored by coarse angular spiral threads 

 (about ten on the penultimate whorl), roughened on the edge 

 by close-set transverse striae, parted by wider furrows, with or 

 without a spiral threadlet. Last whorl with a rounded base 

 prolonged into a longish, sinistrally curved ^' and slightly re- 

 verted beak. 



Aperture round ; outer lip strongly lirate within ; columella 

 with a strong oblique plait at the top of the pillar, having a 

 tooth-like termination ; a sniPvller plait is occasionally present 

 behind it. 



Fig. 8& represents an extreme elate individual with more 

 defined costations. 



Length, 35 ; breadth, 1-1-5 ; length of aperture, 10 ; of canal, 

 S-5. 



Localities. — Turritella clays, Blanche Point, Aldinga Bay ; 

 and Adelaide bore. 



