202 TJk Anni'lCan Gi'ol(fgi.st. October, 18«1 
depression beneath it, neither of wliieli is represented in var. 
intermcdld. 
Formation and lucality: Same as preceding. 
Collected by Mr. Chas. Schuchert, but now in the author's cabiuet. 
Beecherella ovata, n. sp. 
I'l^ATK II, I'KiS \y> AM) 14. 
Size of left valve: Length, al)out 1.87 mm.; liight, 1.10 mm.; 
greatest tliiekness, 0.50 mm.; length of spine, aljout 0.00 mm.; 
projection of same beyond anterior edge, aljout 0.30 mm. 
Of this species the left valve illustrated on the acxiompanying 
plate is all that has so far been discovered. It is a little imper- 
fect at the posterior end but the remainder is in sufficiently good 
condition to justify description. 
Left valve ovate, widest posteriorly, vvitli point of greatest 
hight, about midway between the extremities. Dorsal edge gently 
convex, posterior end semicircular, anterior end sharply rounded 
and most prominent just beneath the spine; ventral edge rathei- 
strongl}- convex, with the curve in the antero- ventral region 
somewhat straightened. Anterior spine rather long and slender, 
lint projecting onl}- aliout half its length bej'ond the anterior edge : 
continuing backward from base of spine a low rounded dorsal 
ridge is traceable across the middle third of the length 
of the valve. From this ridge to the dorsal edge the slope 
is abrupt, while just beneath it a shallow depression, widest and 
deepest at a point a little in front and above the center of the 
valve, is noticeable. Just behind the center an obtuse elevation 
constitutes the point of greatest thickness. Anterior, ventral, 
and posterior slopes gently convex. Surface without ornamentation. 
FoDnittion and locnlity: Same as preceding. 
Type in Dr. C. E. Beecher's collection. 
Beecherella cristata, n. sp. 
PLATE II, FIGS. ll)-l!l. 
Slzr of cutirc carapace: Length, including anterior spine. X.'ll 
mm.; length, without spine, 1.10 mm.; hight, 0.49 mm., thick- 
ness, 0.47 mm. 
Carapace elongate ovate, narrowly rounded Ijehind, acuminate 
in front. Dorsal and ventral sides nearl}' equall}^ convex. In a 
ventral view the two valves are about equally convex, with the 
point of greatest thickness near the middle. Valves unlike, the 
left without spine or crest, but with a narrow flattened border at 
