149 



variety, attaining to a diameter of 31 mills., occur in the River 

 Murray Cliffs, but the perfect shell is yet unknown. 



Genus Harpa. 

 synopsis of species. 

 Whorls rounded at the shoulder. 



Pullus turbinate ; lamellae thin, elevated, about 50 on last 

 whorl. 1. H. lanieUifera. 



Whorls angulated or sub-angulated at the shoulder. 



Whorls sulcated around suture ; lamellae thin, about 40 on 

 last whorl. 2. 7/. suJcosa. 



Spire whorls sub-quadrate ; strongly ribbed spirally and 

 axially ; spire more than half length of aperture. 



3. H. sjnrata. 

 AVhorls upward-sloping to posterior suture. 

 Spire whorls roundly angled. 



Spire less than one-fifth length of aperture ; ribs 

 on last whorl, 12, conspicuously lirate above 

 and belo^v angulation of last whorl. 



4. //. cassinoides. 

 Spire less than one-third length of aperture. 



Pullus papillary, nucleus small, lateral; outer 

 lip slightly expanded. 



Lamella? on last whorl about 20, trans- 

 versely striate ; no lira? 



5. //. ahhreriata. 

 Lamella? on last whorl about 25, lirate 



and transversely striate. 



6. H. tenuis. 

 Pullus large, hemispheric. 



Lamella? about 25 on last wJiorl; outer 



lip thickened. 7. H. jndligera. 



Spire whorls bicarinate at periphery, costa? and lirae 



distant and prominent. 8. //. datJiratn. 



1. Harpa lamellifera, spec. nov. Plate vi., fig. 2. 



Shell ovate, ventricose ; spire very short, ending in a mode- 

 rately large turbinate pullus of tw^o smooth rounded whorls, the 

 last half turn almost concealed. Ordinary whorls, two and a 

 half, convex ; ornamented with thin elevated lamella^, about 50 

 on the last whorl ; interspaces tinely transversely striate and 

 spirally lined. Aperture lunate ; outer lip not thickened, sig- 

 moidally curved coincident with the lamella?. 



Dimensions. — Length, 29; breadth, 19; length of aperture, 

 24; width, 10. 



Loccdity, — Lower beds at Muddy Creek. 



