Jones AND Kirxpy— On Carboniferous Ostracoda from Ireland. 183 
Lower Carboniferous strata, but subrecta is more often present at low horizons than 
Okent. In the East of Scotland Z. subrecta occurs in the Cornstone group of the 
Calciferous Sandstone series; and in the overlying Cement-stone group of the 
same region it is found only in the lower beds. LZ. Oken?, on the other hand, ranges 
from the Cornstone group into the Upper Limestones and Marine Shales of the 
Carboniferous Limestone series of Scotland ; and well towards the top beds of the 
Yoredale rocks of the North of England. 
12. Leperditia inornata (M‘Coy). 
(Plate x1., figs. 15 a, 6, 16a, 6; Plate xu, figs. 1, 2a, b, ¢, 3a, b.) 
1843. Cythere inornata, . . M‘Coy, ‘‘Synops. Char. Carb. Foss. Ireland,” 
p. 167, Pl. xxiu., fig. 18. 
1866. Leperditia Okeni, var. Jones & Kirksey, Ann. Mag. Nat. Hist., ser. 3, 
mornata, vol. xvill., p. 44; 1875, A. M. N. HL, ser. 4, 
vol. xv., p. 54, pl. vi., fig. 2; 1892, A.M.N.H., 
ser. 6, vol. vi., p. 303, pl. xvi., fig. 2. 
These small Leperditioid valves are obliquely sub-ovate, the longest diameter 
being from the antero-dorsal to the postero-ventral region at a low angle. The 
anterior is smaller than the posterior moiety. The valves have a relatively longer 
hinge-line than that shown by the ‘short form” of L. Okent, fig. 2, pl. xx., 1865, 
Ann. Mag. Nat. Hist.; and they vary towards Z. acuta and other allies. 
Prof. M‘Coy’s described specimens came from the Cultra Shales, in company 
with Leperditia subrecta and L. Scotoburdigalensis, and in some instances showed the 
eye-spots. These specimens, in Sir Richard Griffith’s collection, were in a bluish- 
grey fissile shale, fine-grained and micaceous. 
Besides the Irish specimens from Cultra, and near Bundoran, Co. Donegal, 
some of which latter are here figured, we have had similar forms from Russia 
and Mongolia. 
In our previous notices of the small Carboniferous Leperditic, we have been 
influenced by the more or less tangible features and alliances of the several not 
very dissimilar forms; and have regarded them sometimes as varietal, sometimes 
as so-called “specific,” modifications of Z. Okeni, as the synonymies here show. 
We think now, however, that it is advisable, as well as convenient, to arrange 
them as ‘‘ species,” as in the present instance. 
2F 2 
