Millerton-Fishkill Limestones. 153 



Khinebeck. This limestone has been mentioned by Mr. S. W.- 

 Ford, as probably Cambrian, and it contains in considerable 

 quantity what certainly appears like the Potsdam conglomerate 

 of Dutchess and Columbia counties. But the presence of the 

 Calciferous there in a very characteristic form is now beyond 

 doubt. 



Note. — Since the above paper was written, Mr. C. D. Wal- 

 cott's article on the " Position of the Olenellus Fauna," in the 

 July number of this Journal, has been published. In this paper 

 he very justly calls attention to the fact that the fauna here de- 

 scribed belongs to the type of the Middle Cambrian of the in- 

 terior (as of the Rocky Mountain region) rather than to that of 

 the typical Paradoxides of the Atlantic coast ; and that, from its 

 position, the Hudson Valley fauna serves in a measure to connect 

 the two. 



EXPLANATION OF PLATE VI. 

 Cambrian Fossils from Stissing, N. T. 



Natural size, except where otherwise noted. All are from the Calcareous 

 shales, except those represented by figs. 5, 6, and 15, which are from the limestones. 



Pig. 1. Eyolithes Billingsi (?) cast of interior, showing three or four slight annu- 

 lations; the anterior one more prominent than the others. 



Fig. 2. Leperditia ebenina, n. sp., enlarged to 2 diameters ; fragment of (right ?) 

 valve, showing the line of the hinge, and a sloping dorsal angle, also 

 the outer belt of minute contiguous pits, and the inner tract of larger 

 separated pits. The ornamentation indicates that the complete cara- 

 pace must have been at least one-sixth longer than the fragment. 



Fig 3. L. ebenina enlarged to 2 diameters: lacking the cardinal margin; show- 

 ing perfectly the peculiar surface-pitting, and the ventral furrow. 



Fig. 4. L. ebenina, interior view of a central fragment of a valve ; showing the 

 separated tubercles, corresponding to the separated pits of the cen- 

 tral exterior. 



Enlarged to 2 diameters. 



Fig. 5. Kutorgina Stissingensis, n. sp., enlarged 2 diameters; a natural cast of 

 the dorsal valve. 



Fig. 6. K. Stissingensis ; enlarged to 2 diameters ; ventral valve ; with a side 

 view of the elevation. 



Fig. 7. Gutta percha cast of a natural impression of the interior of the umbonal 

 re°ion of a ventral valve, referred to K. Stissingensis ; showing a me- 

 dial septum from which fine striae diverge, and muscular impressions, 

 enlarged to 3 diameters. 



Fig. 8. .K. Stissingensis, cardinal view ; showing false area, deltidial opening. 

 and the rounded edge between the false aiea and the main surface of 

 the valve ; enlarged to 2 diameters. 



Figs. 9. and 10. Olenoides Stissingensis, n. sp.; the glabella. Fig. 9 from an arti- 

 ficial cast, Fig 10 with a side view of the elevation. 



Fig. 11. 0. Stissingensis, pygidium. 



Fig. 12. 0. Stissingensis, pygidium, with four attached thoracic segments. 



Fig. 13. A free cheek, associated with 0. Stissingensis. 



Fig. 14. Hypostoma of 0. Stissingensis. 



Fig. 15. 0. Stissingensis, full length, showing eight thoracic segments; details 

 of the glabella obliterated or distorted by compression. 



