LOWER PALAEOZOIC GATTEROPODA — ETHERIDGE. 77 



hoc. and Horizon. — Cave Flat, Murrumbidgee River, N. S, 

 Wales. Cave Flat Limestone, Siluro-Devonian. 



Genus Holopea, Hall, 1847. 

 (Pal. K York, 1847, i., p. 169). 



Holopea wellingtonensis, sp. nov. 

 PI. XV., Fig. 11 ; PI. xvi., Fig. 7-9. 



(Unnamed shell), Ratte, Proc. Linn. Soc. N.S. Wales, x., 1885, 

 pt. 1, t. 9, f. 3-5. 



Sp. char. — Shell ventricose, of six whorls rapidly decreasing in 

 size above the last or body whorl ; apex acute ; whorls rounded, 

 uniformly ventricose, or almost inflated, very much wider than 

 high, slightly horizontally flattened around the suture ; body 

 whorl very much expanded in proportion to the others. Mouth 

 round ; outer lip sharp and fine ; inner lip straight and slightly 

 thickened. Umbilicus open and deep. Sculpture consisting of a 

 large number of regular, fine, equidistant, sharp revolving threads 

 crossed by others exceedingly fine and oblique, giving rise to a 

 beautiful and minute cancellation ; towards the outer lip are a 

 few coarse sub-laminar ridges. 



06s. — This species was figured, although neither named nor 

 described, by the late Mr. Ratte, but his figure shows a revoluted 

 inner lip that is not present in any of our specimens. 



A similar flattening of the whorls around the suture is seen in 

 Holopea obesa, Winchell.* 



H. wellingtonensis is not unlike some forms of Callonema, Hall, 

 but possess spiral and growth threads, instead of the latter only, 

 and also lacks the obtuse angularity on the anterior part of the 

 body whorl that is almost always seen in species of Hall's genus. 

 Both Holopea and Callonema are umbilicated. 



Loc. and Horizon. — Wellington Caves, N.S. Wales. Siluro- 

 Devonian. 



* Geol. Wisconsin, 1873 - 79, iv., 1882, p. 348, t. 27, f . 4. 



