36 BULLETIN 115, UNITED STATES NATIONAL MUSEUM. 



DOLATOCRINUS LAMELLOSUS Hall. 



Cacabocrinus lamellosus Hall, Fifteenth Report, New York State Cab., 1862, p. 141 



This s])ecies has never been figured. What purports to be the 

 type specimen in the American Museum of Natural History has only 

 the dorsal parts preserved. It is a very large, crushed specimen 

 about 55 mm. wide, with plate arrangement similar to that of D. 

 sinnosus. Although recorded by Hall as from western Xew York, 

 without definite locality, this specimen, lying with some others from 

 Louisville, strongly resembles them in ap])earance, and may be from 

 the same locality. It may be identical with spinosus, and if so would 

 take priority; but inasmuch as we know nothing of the tegmen, in 

 which one of the important characters of that s])ecies occurs, the 

 evidence is insufficient for a decision, and the j^ounger name will 

 have to stand, leaving the other one in doubt. 



Horizon and locality. — ? Hamilton shales of western New York. 



DOLATOCRINUS INSUETUS Rowley. 



Plate 8, fig. 8. 



Dolatocrinus insuetus Rowley in Greene, vol. 2, 1906, p. 8, pi. 3, fig. 4. 

 Dolatocrinus ercavatus Rowley in Greene, 1903, p. 191, pi. 57, fig. 17. 



Of the type of D. spinosus, but the keellike ridges traverse the 

 entire radial series to the arm bases; and the tegmen, instead of 

 strong spines, has usually only a few sharp tubercles. It is a good 

 species, definitely marked, and I am glad to be able to confirm Pro- 

 fessor Rowley's description by four fine specimens in which the cor- 

 relation of the above noted characters is fairly constant. 



Horizon and locality. — Onondaga (Jeffersonville) limestone: Louis- 

 ville, Kentucky, and vicinity. 



DOLATOCRINUS MAJOR Wachsmuth and Springer. 



Plate 9, figs. 1, 2. 



Dolatocrinus major Wachsmuth and Springer, North American Crinoidea Camer- 

 ata, 1897, p. 312, pi. 25, fig. 5. 



This is another very striking species of the Onondaga, hitherto but 

 little known, which is marked by some decisive characters. When 

 described, the type was the only specimen known, and that one 

 lacked the tegmen; but the subsequent acquisition of eight additional 

 specimens has confirmed the diagnosis, while also showing a consid- 

 erable range of variation within a strong specific tyj^e. The position 

 and arrangement of the pinnule o])enings resemble those of D. 

 grandis, reduced in number owing to the doubling of the arms, and 

 there is also a sporadic appearance of 2 plates in the second inter- 

 brachial range; but otherwise there is no close relation to that species. 



This form is usuall}^ of very large size, flattened specimens ranging 

 from 50 to 75 mm. in width, but even a small one of only 40 mm. 



