On some Pakeozoic Ostracoda. — Jones. 341 
larger, more convex, and usually bears either the muscle-spot 
or the eye-tubercle. 
Only two specimens of L. suhquadrata have been noticed. 
They are from .75 to 1 mm. in length. From the before men- 
tioned dark-gray Lower Helderberg limestone of Perry county, 
Pennsylvania. 
3. KLCEDENIA PENNSYLVANICA. Sp. nov. FigS. 5-9. 
Numerous specimens of a Kloadenia^ near to Kl. notata 
(Hall), occur in the dark-colored Lower Helderberg limestone 
from Perry county. Pa. They vary from about 1 to 2 mm. in 
length. Prof. Claypole referred them to Dr. James Hall's 
Beyrichia notata, but I find from good typical specimens of 
this species that its valves are larger, and more nearly 
approach those of Kloadenia wilcJiensiana, though the lobes 
and sulci are not so strongly pronounced as in the latter. 
In the Pennsylvanian species the middle lobe is narrowed 
by its two, short, strong, parallel, lateral sulci ; herein diiSer- 
ing from both of the other species alluded to. 
The figures exhibit the chief variations in outline and pro- 
portions of parts. In figs. 7a and 9 we see a faint sulcation 
of the hinder lobe, analogous to the posterior furrow in figs. 
17, 18 and 19, of plate 5, "Ann. Mag. Nat. Hist."ser. 2, vol.xvi 
(1855). This feature is strongly emphasized in A^/.7>Z/ca^a 
Jones op. cit. figs 20, 21 ; and op. cit. ser. 5, vol. xvii(1886), pp. 
347 and 362 ; and ser. 6, vol. i (1888), p. 398. A faint indica- 
tion of a delicate reticulation is observable on the surface of 
some specimens. 
EXPLANATION OF PLATE. 
Fig. 1. Bythocypris favulosa, sp. nov. Cast of the inside of a right 
valve; x 15 diatn. 
2. B. favulosa, sp. nov. a, hollow cast of the outside of right valve ; 
X 15 diam. ; b, appearance of the inside of the hollow cast, x 4ii diam. ; 
c, reversed drawing of 26, showing it as the original reticulation ; x 40 
diam. 
3. B. oviformis, sp. nov. Complete carapace, a, showing the right 
valve and edges of the left valve; b. showing the left valve ; c, the 
dorsal aspect; d, posterior aspect; all magnitied 40 diam. ; e, outline 
of the carapace, x 15 diam. 
4. Leperditia subguadrata. sp. nov. Complete carapace, a, show- 
ing the l(^ft valve; b, dorsal aspect; c, posterior aspect; all x 40 
diam. ; d, outline C'f carapace, x 15 diam. 
5-9. Kladenia penvsylvanica sp. nov. All magnified 15 diam. 5a, 
complete carapace, with the left valve outwards; 56, right valve ; 5c, 
ventral aspect ; bd, end view ; 6, left valve ; la, carapace showing the 
right valve and the edges of the other ; lb, ventral aspect ; 8, a large 
