New and Little Known American Faleozoic Ostracoda. 193 
two, but further examination will show that in the Devonian species 
the marginal ridge is much more elevated, and the reticulated area 
not nearly so convex. 
Position and locality: Same as the preceding. 
4 
KIRKBYA SEMIMURALIS, Nn. sp. 
Line NV HUGS, 2 @, 0s 4 a, 0, €. 
cre | lig. 3@; length, 0.7 mm.; height, 0.41. 
Ee AG i hes Ox One £6 Si Ords 
This species varies somewhat, but may be described as sub- 
oblong, or elongate elliptical, with a straight back, obtuse cardinal 
angles, subequal rounded ends, and slightly convex ventral edge. 
Marginal ridge sharply elevated in the posterior region, but dying 
out before reaching the anterior end; margin outside of ridge a 
smooth, convex slope to edge of valve. Within the ridge the 
depressed-convex surface is delicately reticulated, with the meshes 
rather large, and extending to the anterior edge. Umbilical pit 
large but faintly impressed. Valves very thin and frail. 
Position and locality : Same as the preceding. 
OCTONARIA STIGMATA, Nl. SD. 
Plate XVI, Figs. 8 a, 6; var. oblonga, figs. 9 a, 6,¢; var. loculosa, 
jig. Lo. 
It is very difficult to distinguish the back from the ventral edge, 
and the anterior from the posterior end in species of this peculiar 
genus. If my arrangement of the figures of the three species and 
varieties on plate 16 is correct, then I have in each case illustrated 
a right valve. To save time and type we will assume that the 
parts have been correctly determined. 
Species variable; valves with a raised and longitudinally ridged 
area occupying most of the surface. Ridges more or less irregu- 
larly thickened at intervals, or united by a greater or less number 
of cross-bars, producing a coarse network. 
The typical form (figs. 8 a, 8 4) is ovoid or subrhomboidal in 
shape, with the anterior extremity the narrowest; posterior end 
strongly curved in the lower half, sloping forward in the upper 
