New and Little Known American Paleozoic Ostracoda. 207 
boniferous A. oblonga may be considered as reasonably certain. 
Slight differences might be pointed out, but considering the varia- 
bility of the species, it is highly improbable that they would prove 
constant. 
Position and locality: Shaly limestones near the middle of the 
Chester group, at Chester, Ill., and near Grayson Springs, Ky. 
KIRKBYA LINDAHLI, N. sp. 
Plate XVITT, Figs. 6a, 63 ¢. 
Size:) Length, 2.3° mm:; height, 1.3 mm.; thickness of right 
valve, 0.65 mm. 
Valves comparatively large, strongly convex, suboblong-ovate, 
slightly oblique, widest in the posterior half, with the ends equally 
curved, the back straightened, the cardinal angles obtuse, the ven- 
tral edge straight ‘or very gently convex at the center and curving 
uniformly up at each end. Marginal ridge thin, nearly equally 
elevated all around the free margins. Body of valve strongly con- 
vex, with point of greatest convexity just behind the center, where 
a slight protuberance is noticeable. Just in front of this prominence 
a vertically elongate umbilical pit. Entire surface beautifully retic- 
ulate. 
This fine species, which it gives me pleasure to name for my 
friend Dr. Josua Lindahl, State geologist of Illinois, is related to 
K. oblonga, J. & K., but is much larger, with coarser reticulation, 
and narrow instead of rounded umbilical pit. Other differences 
might be pointed out, but these will suffice. 
Position and locality: Warsaw beds of the St. Louis group, at 
Columbia, Ill. 
KIRKBYA TRICOLLINA, Jones and Kirkby. 
Plate XVIII, Figs. 8 a, b. 
Kirkbya tricollina, Jones and Kirkby, Ann. Mag. Nat. Hist., 
pers. Vol. XVIUl Plate. VIII, Fig. 19... 
Size: : Length, 0.75 mm.; height, 0.43 mm. 
The American specimens of this species differ in several unim- 
portant respects from the British form as figured by the authors of 
the species. Chief among these is the greater prominence of the 
