from the Taconic Series at Canaan, JV. Y. 



251 



section and the second a polished rock surface, illustrate this 

 fact, and are not exceptional in character. Other slides show 

 these features less perfectly, while in still others their definition is 

 even sharper, as in figs. 3 a-b. This latter form we think may 

 represent the column of some known species of Beterocrinus. 

 Associated with it there occur the forms shown in figs. 3 c-f 

 which we look upon as joints of encrinal stalks ; also the forms 

 represented by figs. 3 g-j\ which we are disposed to regard as 

 more or less oblique longitudinal sections of the same or similar 

 columns. All of the forms illustrated by figs. a-j, have been 

 brought out by means of transparent rock slices, and so strongly 

 resemble, in many respects, certain forms shown in similar 

 slices of limestone of undoubted Trenton age, that we can 

 scarcely doubt the correctness of our interpretations of them. 

 Forms 3 g-i, which are quite common, proved extremely 

 puzzling, and have been referred as above only after much 

 laborious comparison. 



In the same layers affording the fossils just mentioned, there 

 occur other and larger forms, which appear to us to be likewise 

 crinoidean, with a strong probability that they represent the 

 remarkable species found so abundantly in the Trenton at 

 Newburgh, N. Y., known as Gleiocrinus magnificus Billings.* 

 Transverse sections of several of 

 the supposed columns of this spe- 

 cies are shown in figs. 4 e-i in- 

 clusive, and portions of several 

 columns, an inch or more in 

 length, are shown in figs. 4 a-d. 

 The absence in these forms, of 

 the minute details of structure so 

 admirably exhibited in the New- 

 burgh specimens, forbids our 

 reaching entirely satisfactory con- 

 clusions as to their identity ; but 

 the general form of the Canaan 

 specimens, their size, thickness 

 of walls, more or less crystalline, 

 radiating structure, as shown in 

 the transverse section (fig. 4 e) so 

 characteristic of crinoidal col- 

 umns ; their surface markings 

 which, upon such weathered spec- 

 imens as represented by figs. 4 a, 

 close transverse joints, and the evident occurrence of encrinal 

 columns of large size associated with the smaller ones, as in 

 fig. 2, all point toward such identity. Some of the columns 



* Geological Survey of Canada, Decade IV, page 54, Plate 5, fig. 3. 



Crinoids from Newburgii, 2f. Y., 

 natural size. — Nos. 1, 2 and 4, Glei- 

 ocrinus magnificus (Billings). No. 1, 

 end view of a specimen which is 

 rounded by weathering, and thick- 

 ened within by incrustation. No. 

 2 is somewhat compressed in a ver- 

 tical plane. No. 4 is broken open 

 and very much flattened. No. 3. 

 Gleiocrinus grandis (Billings), end 

 view of a very perfect specimen, 

 giving all the characteristic features. 



b and d seem indicative of 



