358 Beport of the State GEOLoaisT. 



Cyrtina lachrymosa. 



Plate 8, figs 1-3. 



Cyrtina lachrymosa, Hall. Palaeontology of N. Y. , vol. VIII, pt. 2, p . 362, pi. 

 xxviii, figs. 36, 37, 47. 1894. 



Shells small ; cardinal area high, more or less inLCurved. Sur- 

 face with low and rather narrow median fold and sinus, on each 

 side of which are two or three low, faint plications. Lateral 

 margins of the cardinal area broadly rounded. Surface covered 

 with elongate pustules, some of them coarse, but the greater 

 number quite fine. 



Height of an average specimen, 5 mm.; width and length 

 6 mm. 



Waverly group. Biehfield^ Ohio. 



Syringothyris Missouri. 



Plate8, figs. 14-16. 



Syringothyris Missouri, Hall. Palaeontology of N. Y., vol. VIII, pt. 2, p. 

 363, pi. xxxix, figs. 29-31. 1894. 



Shell small, cyrtiniform ; cardinal area high, slightly incurved 

 toward the apex ; lateral cardinal margin broadly rounded, ren- 

 dering the definition of the area quite obscure. Median fold and 

 sinus neither wide nor highly developed. Surface of both 

 smooth. Each lateral slope with five or six low plications. 

 Interiorly the pedicle- valve bears strong divergent dental 

 lamellae which are attached to the surface of the valve for fully 

 one third of its length. There is no median septum. The trans- 

 verse delthyrial plate is thin and is developed into a delicate but 

 distinct tube. Shell substance- highly punctate on the inner 

 laminae. Height of original specimen, 13 mm. ; cardinal width, 

 18 mm. ; length, 15 mm-. 



Choteau limestone. Chateau Springs, Missouri. 



Athyris densa. 



Plate 9, figs. 3-9. 



Athyris densa, Hall. Palaeontology of N. Y. , vol. VIII, pt. 2, p. 364, pi. xlvi, 

 figs. 6-12. 1894. 



Shell transversely elongate, valves compressed ; median fold 

 and sinus not conspicuously developed. Pedicle- valve shallow, 

 with broad, sharply angled cardinal slopes, greatly thickened 



