l^Q REPORT ON THE STATE CABINET. 



In the Hamilton group are found : 



Strophodonta concava, 



S. jiet'plana, Conrad (which has been described under the 



names Strophomena perplana, S. pluristriata, and S. 



delthyris, Conrad; and as *S'. nervosa, S. crenistria, and 



8. fragilis, Hall); 



8trophodonta demissa, 

 S. naa^ea, 



In the Chemung group are found : 



Strophodonta inequistriata, 

 8. junia* 



8trophodonta cayvta (n. s.), I Strophodonta perplana var. nervosa, 



8. mucronata, 8. demissa. 



8. coilata (n. s.), | 



In the Genus Chonetes, we find verified in a very satisfactory manner 

 the observations made by Count Von Keyserling, in regard to the direc- 

 tion of the tubes or spine-bases in the area of the ventral valve. These 

 tubes are directed from the hinge-line towards the apex of the valve, and 

 parallel to the sides of the triangular fissure. They appear on the crest 

 of the area as little pustules or elongated tubular spines, which may be 

 either vertical to the hinge-line or directed outwards. 



In the Upper Helderberg and Hamilton groups, we have the following 

 species : 



Chonetes hemispherica, 



0. 



arcuata, 



0. 



acutiradiata, 



0. 



lineata, 



0. 



yandellana, 



0. 



mucronata, 



0. 



deflecta, 



Chonetes pusilla, 

 C. setigera, 



C. scitula, 



C. lepida, 



C. coronata, 



C. logani. 



The occurrence of this last named species in the TuUy limestone is a 

 fact of great interest, carrying back the appearance of this species to 

 a much earlier epoch than had heretofore been known. The species 

 occupies a limited area in the Tully limestone of New York, and is not 

 known in the Chemung group within the State; though found in the 

 sandstones of the same age in Ohio, and in the beds at the base of the Bur- 

 lington limestone in Iowa and Illinois. 



In the Chemung group we have the recurrence of Chonetes scitula^ C. 

 lepida and G. setigera; with a new and remarkable species, the C muricata, 



*S. Junia = 5. textilis, Pal. N. Y., Vol. IV, p. 108; the latter name being a synonym. 



