44 C. L. HERRICK — THE CUYAHOGA AND WAVERLY. 



CYTHERELLA UNIONIFORMIS, SP. N. 

 {Plate 1, figs. 8-W.) 



Carapace elongate, subovate, acutely rounded behind, the greatest pro- 

 longation above the middle; anterior margin oblique at an angle of 120° 

 with the hinge nearly straight ; hiiige-line nearly straight ; ventral margin 

 a gentle curve; valves similar, gently convex, slightly compressed posteri- 

 orly, abruptly deflexed anteriorly. In the cast a ridge appears nearly 

 parallel to the anterior margin, from which the surface descends abruptly 

 to the margin. The ridge terminates in a conical projection (indicating 

 a pit in the interior of the valve which may or may not have a corre- 

 sponding external elevation), from which a faint ridge passes obliquely 

 backward toward the superior margin. Muscle pit large, nearly central, 

 and surrounded by a nearly circular ridge. Greatest width near the middle. 

 Length (.04 ± mm.) about 1.7 times the width and about 2.5 times the 

 thickness. 



This species is very abundant in the upper layers with Phillipsia merame- 

 censis. Another entomostracon is figured on plate 1 (fig. 11), the description 

 of which is reserved. A considerable number of species of Cytherella are in 

 our collections from other horizons of the Waverly series, but the present 

 species is the most characteristic and widely distributed. The same or a 

 very similar species occurs in the upper layers of the Cuyahoga shale. 



LEPTODESMA NASUTUS, HERRICK.* 

 {Plate \, fig. 6.) 



This species, briefly indicated in an earlier publication,t proves to be 

 widely distributed, though nowhere common upon the horizon of the con- 

 cretionary zone of Moot's run. The right valve figured is from Burbank, 

 Ohio, and differs in no obvious respect from the corresponding valve of the 

 Chemung species quoted. On the other hand, other specimens connect it 

 with L. ortoni from a somew^hat higher horizon. 



LEIOPTERIA CUYAHOGA, SP. N. 

 {Plate hfig. 7.) 



Species of small or medium size, subrhomboidal, oblique, subfalcate; body 

 narrow, compressed, produced posteriorly, sharply elevated at the post- 

 umbonal ridge, forming an angle of 30° with the hinge-line ; height equal 

 to less than two-thirds the length ; basal margin gently curved, posterior 

 margin sinuate; byssal sinus moderate; left valve sharply elevated at the 

 post-umbonal ridge, sloping to the ventral margin by a very flat curve ; 

 hinge straight, shorter than posterior prolongation of the body ; wing de- 



Cf. L. hector. Hall. f Bui. Denison Univ., vol. IV, 1888, p. 29. 



