New and Little Known American Paleozoic Ostracoda. 127 
body of the valve, then convex and marked with rather obscure 
radial furrows; with or without a narrow, flattened, terminal border. 
Dimensions of a large right valve: Entire length, 2.25 mm.; 
greatest height (posterior half), 1.25 mm.; length of body of 
valve, 1.5 mm.; height of same, 0.9 mm.; average width of mar- 
ginal area, 0.35 mm.; greatest width of same, 0.45 mm.; greatest 
convexity of single valve, 0.25 mm. 
The absence of surface reticulation, pinched appearance of the 
central portion of the valves, stronger tubercle, wider sulcus and 
more abruptly elevated marginal area, together with other differences 
will readily enough distinguish the species from £. reticulata. The 
Manitoba species is more uniformly convex and has a narrower 
marginal area without radial striz or furrows. In other respects 
it is closely related. 
Position and locality: This species has a wide geographical dis- 
tribution, but apparently is not abundant anywhere. I have spec- 
iImens from Lower Trenton or Birdseye limestone at Lebanon, 
‘Tenn., Dixon, Ill., and Minneapolis, Minn. 
EURYCHILINA LONGULA, N. sp. 
Flate IX, Figs. 3 a, 6, and 4. 
Valves elongate, sub-elliptical, dorsal and ventral margins sub- 
parallel. Dorsal margin long, straight, the points of junction with 
the equally rounded ends not forming angles though quickly turn- 
ing into them. Ventral margin gently convex. Body of valve 
semicircular or elongate subelliptical, moderately and nearly uni- 
formly convex, with point of greatest convexity just below the 
well-defined and rather broad, but not deeply impressed mesial 
sulcus. Just back of the sulcus a broad and not very prominent 
tubercle. Surface smooth. Marginal area double and widest at 
the anterior end; at the ventral side its width is equal to fully one- 
fourth of the height of the entire valve. The folding of the area 
is characteristic. Beginning at the margin of the body it rises 
rapidly into a narrowly convex rim, from which it slopes down 
again only to be brought up once more by the development of a 
delicate ‘‘frill.”” Surface of marginal area without ornamentation 
of any kind. 
Dimensions of a perfect but small right valve: Entire length, 
