THE OSTRACODOUS GENUS BATRDIA. 575 
9. Barrpra suseracizis, Geinitz, Plate XXX. fig. 17. 
Bardia gracilis, Jones (non M‘Coy), 1850, in King’s Monogr. 
Perm. Foss. p. 63, pl. 18. fig. 7.’ 
B. gracilis, Reuss, 1854, Jahresb. wetter. Gesellsch. 1854, p. 65, 
figs. 2a, 26, 3. 
B. gracilis, Richter, 1855, Zeitsch. deut. geol. Ges. vol. vii. p. 530, 
pl. 26. figs. 16, 17. 
Cythere (Bairdia) gracilis (M‘Coy ?), Jones, 1859, Trans. Tyne- 
side N. F.-Club, vol. iv. p. 168, pl. xi. fig. 15. 
Bairdia subgracilis, Geinitz, 1861, ‘ Dyas,’ p. 34, figs. 9a-c. 
From the ‘“ Main Limestone” of the Carluke district we have 
examples of an elongate Bazrdia (fig. 17) possessing a more strongly 
conyex dorsal and incurved ventral border than any specimens we 
have described as belonging to B. subelongata. They have altogether 
a curved outline, the dorsal border being convex and the ventral 
border concave, with the anterior half of the carapace considerably 
the larger. The posterior extremity is pointed, and the anterior 
rounded. These specimens have not the shell well preserved; but, 
so far as can be judged, they come very near the Permian form, 
which one of us identified with B. gracilis, M‘Coy, and which Dr. 
Geinitz has since named subgracilis. 
The figures given for this species by Reuss, Richter, and Geinitz 
differ somewhat among themselves as to the relative proportions of 
the posterior third of the carapace ; but the general shape sufficiently 
accords throughout to indicate a specific alliance. 
10. Barrpra Brevis, Jones & Kirkby. Plate XXXI. figs. 1-8. 
B. brevis, J. & K. 1867, Trans. Geol. Soc. Glasgow, vol. ii. 
p. 221. 
B. brevis, J. & K. 1871, Armstrong and Young’s Cat. Carb. Foss. 
of West Scotland, p. 25. 
Subrhomboidal; length about half as much again as the height. 
Dorsal border boldly convex, the posterior slope of the arch being 
much the deepest and rather concave; ventral border convex in 
most examples, but in some nearly straight in the centre and rounded 
towards the ends. Anterior extremity broad, rounded, or subtrun- 
cate, most prominent above; posterior extremity rostrated, with 
the beak usually more or less acute. Lateral contour broadly lenti- 
cular, with the greatest width in the centre, which is rather less 
than half the length. Surface smooth. Length = to 4, inch. 
The specimens figured show the most important variations of out- 
line. Such variations mainly relate to the amount of inward slope 
of the anterior extremity, as depicted in figs. 3 & 5, and to the con- 
yexity of the yentral border, which, in such examples as are repre- - 
sented by figs. 2 & 3, forms a bold sweep continuous with the inferior 
slopes of the two extremities, while in others (fig. 5) it is flattened 
in the centre to nearly a right line. 
Compared with its height (about two thirds of the length), this is 
the shortest species of the genus. 
Localities. In England this species has been found in the Carbo- 
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