PLATE XLIX. 
G-yrooeras spinosum. 
Page 382. 
See Plates 47, 48, 98, 99. 
Pig. 1. Lateral view of a large, compressed fragment, showing the curvature of the tube and the depth of 
the air-chambers. On the concavo-dorsal side the test is preserved, and shows the undulating, 
lamellose lines of growth. Schoharie grit. Schoharie, N. Y. 
GyROCERAS validum. 
Page 385. 
See Plate 100. 
Fig. 2. Lateral view of a large fragment, preserving the chamber of habitation and twenty-six attached 
air-chambers, showing the eurvature and form of the shell, with no traces of a prominent orna¬ 
mentation of the test preserved on the internal mould. Schoharie grit. Schoharie, N. Y. 
