268 " PALEOZOIC PALEONTOLOGY. 
BEYRICHIA SMOCKI N. sp. 
Plate XXIV., Fig. 24. 
Description.—Carapace subelliptical in outline, a little narrower in 
front, hinge-line straight, about nine-elevenths of the total length of 
the valve. Free margin depressed, with a narrow, concave furrow 
within, which is bordered externally by a narrow, rounded elevation, 
outside of which the surface drops abruptly to the edge of the valve. 
Along the postero-ventral margin the border is hidden for a short 
distance by the protrusion of the body of the valve. Valves divided 
into three lobes by two vertical furrows; the posterior furrow longest, 
reaching below the middle of the valve, its lower portion shghtly 
curved toward the front; anterior furrow narrower, shorter and deeply 
impressed, curving backwards. Posterior lobe strongly convex, its 
greatest elevation nearest its anterior margin; median lobe sub- 
globular, about as highly elevated as the posterior one; anterior lobe 
much lower, sloping gently to the anterior margin. Surface of valves 
smooth. 
The dimensions of the type specimen are: length, 2.6 mm.; height, 
1.5 mm. 
BEYRICHIA MANUIENSIS Nl. Sp. 
Plate XXIII., Fig. 10. 
Description.—Carapace subelliptical, slightly narrower in front, the 
hinge-line straight, a little more than five-sixths of the entire length 
of the valve. Free margin of the valve with a flattened border. Valve 
divided into three lobes by two furrows extending from the hinge-line 
vertically downward; posterior furrow reaching to about the middle 
of the valve; the anterior furrow shorter, its lower extremity curving 
shightly backward below. Posterior lobe depressed-convex, occupying 
nearly one-half of the entire valve; median lobe most prominent, sub- 
globose; anterior lobe nearly equaling the posterior in convexity and 
about equaling the median one in width. Entire surface, except in the 
furrows and on the marginal border, marked by small, closely-ar- 
ranged. subcircular pits. 
The dimensions of the type specimen are: length, 3 mm.; height, 
1.9 mm. 
