282 SMITHSONIAN INSTITUTION 



visible in the fossils as preserved I am unable to separate them. The largest specimens are 

 from Waldron, but none have been found there with the arms preserved beyond the IVBr. 



The calyx wall is very thin in its lowest part, being in the largest specimen less than one 

 millimeter in thickness from the first primibrach to the tertibrachs, but increasing somewhat 

 above that; and there is to be observed a slight tendency to the lateral distortion near the 

 base so frequent in /. corbis. 



The species was originally described from the specimen which was afterward figured 

 in the 20th Report of the New York State Cabinet of Natural History, plate II, figure 16, 

 again in the 28th Report, plate 16, figure 13, and which I have refigured (PL XXXIV, fig. 1). 

 It is not exactly characteristic of-the form of the crown as now known from other specimens, 

 being more convex and less elongate and angular — probably due to vertical compression. 

 Hall afterward in the nth Report of the Indiana Geological Survey, plate 15, figure 13, 

 figured a large specimen with the ray divisions preserved to a greater length than in any 

 other Waldron specimen known; this I have also refigured (PL XXXIV, fig. 6). These, 

 together with my own specimens which show the base and undistorted form of the calyx 

 somewhat better (figs. 2, 3, 4, 5), give the best obtainable representation of the species. 



I have also refigured on the same plate (fig. ,7) the specimen from Bridgeport, Illinois, 

 figured by Hall in the 20th Report, plate n, figure 15, which is discussed under /. corbis. 

 This specimen with the external surface preserved is strikingly similar to the present species 

 except in its imperfect base, and it is difficult to conceive how the internal cast of its calyx 

 could in any way have resembled the singularly distorted figure of /. corbis, so common in 

 the same formation. The improbability of such a resemblance is emphasized by the fact 

 that other Bridgeport specimens in my collection consisting" of casts like those of /. corbis 

 are in proportions, size of plates, contour at the base and angular ridges, excellent examples 

 of /. snbangularis as found at Waldron (PL XXXIV, fig. 8). 



Types. There is some conflict in the claims to possession of the type specimens in the 

 Lists of Types issued respectively by the American Museum of Natural History at New York, 

 and the New York State Museum at Albany. Having through the courtesy of the authori- 

 ties of those Museums had the opportunity to carefully examine all the actual and supposed 

 types, I am able to state the facts with certainty : The type specimen, on which the species 

 was originally described in the Transactions of the Albany Institute, volume 4, p. 201, is 

 the one figured in the 20th Regent's Report, plate 1.1, figure 16, and refigured in the 28th 

 Report, plate 16, figure 13. This specimen, and the originals of Hall's figures in the 20th 

 Report, plate II, figure 15 (the Bridgeport specimen), and in the 28th Report, plate 16, 

 figures n and 12, are in the American Museum. The originals of the nth Indiana Report, 

 plate 15, figures 12 and 13, are in the New York State Museum. The figures on plate 16 of 

 the 28th Report were republished under the same numbers in the nth Indiana Report, being 

 printed from the same stone. 



Horizon and locality. Silurian, Waldron shales at Waldron, Indiana ; Racine dolomite 

 at Chicago (Bridgeport), Illinois; Rochester shales, Lockport, New York. 



Ichthyocrinus intermedins Angelin 

 Plate XXXIV, figs, n-14 



Ichthyocrinus intermedins Angelin, Icon. Crin. Sueciae, 1878, p. 13, pi. 17, fig. 7. — Wachsmuth and' 

 Springer, Revision Palaeocrinoidea, pt. 1, 1879, p. 34. — Springer, Jour. Geology, XIV, 1906, pi. 6, 

 fig- 5- 



Angelin described under this name a complete crown from Faro, in Gotland, which has 

 the chief essential characters of the American species, snbangularis, differing however in 

 having the base rounded or curving evenly with the calyx wall, instead of being contracted 

 into a distinct neck sharply truncate below. His figure was poor, and I have therefore given 



