CRINOID GENUS SCYPHOCRINUS 49 



mentioned filled with the remains of calices and bulbous roots, all broken into 

 small pieces. Many of these have the surface structures, both external and 

 internal, beautifully preserved, and I have figured several of them on Plate VI, 

 for various details. They show, among other things, pits resembling folds upon 

 the sutural edges of the plates in a dorsoventral direction, already described; 

 and also radiating striae upon the inner surface of the plates. 



Types. — Author's collection. The specimens figured on Plate VIII are con- 

 sidered the types rather than those on Plate VI, the figures of which were 

 drawn from imperfect specimens and printed before the later material was 

 obtained. 



Horizon and locality. — Niagaran to Helderbergian, from the Decatur lime- 

 stone throughout the Linden formation; Hardin, Perry, and Benton counties, 

 Tennessee. 



4. SCYPHOCRINUS STELLATUS (Hall) 

 Plate VII, figs. 40, b 



1879. Camarocrinus stellatus Hall ; 28th Rep. N. Y. St. Mus. Nat. Hist., 270, pi. 35, 



figs. 1-8. 

 1904. Camarocrinus stellatus Hall; Schuchert, Smithson. Misc. Coll., vol. 47, pt. 2, pp. 269, 



270, pi. 44, figs. 1-5. 

 1913. Camarocrinus stellatus Hall; Schuchert, Maryland Geol. Surv., Lower Devonian, 228, 



pi. 31, figs. 1-5. 



Calyx short, obconical, spreading gradually to the arm-bases ; height about 

 equal to maximum width. Plates low, rugose, with indistinct radiating mark- 

 ings below, and strong connecting ridges and deep pits above, producing a low, 

 stellate sculpture. Secundibrachs about 10, the upper ones about half as long 

 as wide, being relatively longer than in many other species. Median ridge 

 narrow. Arms and stem unknown. 



The form of Camarocrinus occurring numerously at Schoharie, New York, 

 and in the beds at Keyser, West Virginia, mentioned by Hall and Schuchert, 

 was described by the former under the above specific name. A single imperfect 

 calyx has been found in the Keyser locality, upon which I have undertaken 

 to characterize the species. Some of the fragments from Benton County, 

 Tennessee, may belong to this species. While the bulbs from the Keyser locality 

 contain numerous examples of the primitive four lobes, and variations from 

 that number to eleven, it must be said that taken as a whole they show a much 

 greater tendency to increase in number of lobes than those from Oklahoma 

 and Tennessee. Therefore, while a single bulb would prove nothing, the preva- 

 lence of the higher numbers in a considerable assemblage of specimens may 

 be taken as a specific character. Also on an average those of this locality are 

 relatively lower and broader than the others, and in general considerably 

 smaller. 



