74 . 
Eurydesma cordatum, Morris, var. sacculum, Dana. 
(Plate XIX, Figs. 1 and 2 ; PL XX, Fig. 1 ; PI. XXIV, Figs. 1 and 2.) 
Eurydesma sacculu^ Dana, AA^ilkes’ U.S. E.xplor. Exped., GeoL, X, 1819, p. 700, PI. vii, 
tigs. 8, a-e (non Pachydomus sacctilus, McCoy.) 
Notomya Qouldi, R. M. Johnston, Syst. Acc. Geol. Tas., 1882, PI. xvii, fig. 1. 
Eurydesma sacculus, Eth. fil., Geol. Pal. Q’land., (kc., 1892, p. 273 (excl. first syii.). 
Ohserratlons. — A very variable feature on the valve flanks of 
E. eordatum is a shallow cincture extending usually from the rounded 
postero- ventral marginal junctions some little distance in the direction. of the 
rounded diagonal ridges, or it may he situated more anteriorly ; at times the 
only indication of this cincture is a flattening of the valve surfaces. Dana’s 
illustration of his E. sacculus represents an extreme development of the 
cinctures, and Johnston’s figure of Notomya Gouldi a still greater. 
The figure of Notomya Gouldi also illustrates the ventral extension 
of the valves already referred to. 
Localities. — Allandale, near West Maitland — Permo-Carhoniferous, 
Lower Marine Series. Bridgewater, Tasmania {R. M. Johnston)— \^evmo- 
Carhoniferous, Lower Marine Series. 
Collections. — Mining and Geological Museum ; Australian Museum. 
Eurydesma cordatum var. ovale, Eth. fil. Dun. 
(Plate XXI, Figs. 4 and 5 ; PI. XXV, Figs. 1 and 2.) 
Observations. — ATe aj)ply tliis varietal name to a form intermediate 
between the typical condition of E. cordatum and E. hobartense. It is more 
truly oval in outline than the species in chief, and usually less rohiist and 
ventricose, thereby approximating to Johnston’s Tasmanian species. It is 
also restricted, so far as we at present know, to a particular horizon in the 
Lower Marine Series — the Kavenswood Sandstone, separating the Earley and 
Lochinvar Stages. 
Localities. — Bavensfield Quarry (G. Cullen, T. Browne) : Eavens- 
wmrth Quarry [TV. S. Dun) — Permo-Carboniferous, Lower Marine Series. 
Collection. — Mining and Geological Museum. 
