374 A. W. GRABAU — SILURO-DEVONIC CONTACT IN NEW YORK 



Explanation of Plates* 



Plate 21. — Ma alius Limestone Fossils, Erie County, New York 

 ( All are natural size except figures 2a-b, which are X 2 ) 



Page 



Figure la-d. Cyathophyllum hydraulicum Simpson 364 



la. Showing slender cylindrical youthful stages, free from costee. 

 lb. A normal individual with the young stages broken away, 

 lc. An uncommonly regular individual, showing strong costee. 

 Id. Calyx. 



(After Simpson, drawn from gutta-percha casts) 



Figure 2a-b. Spirifer eriensis Grabau 366 



2a. Pedicle valve X 2. 



26. Brachial valve of a smaller individual X 2. 



Figure Sa-b. Trochoceras gebhardii Hall 371 



3a. Side view, showing the spire. 

 3b. Umbilical view. 



*The fossils were drawn by Miss Elvira Wood, instructor of paleontology in the Massachusetts 



Institute of Technology. 



