30 BULLETIX 115, UNITED STATES NATIONAL MUSEUM. 



specimens both of the original species and the variety, being broadh' 

 and rather deeply lobed, and covered over the entire surface with 

 numerous small projecting tubercles. One little point peculiar to 

 this species is a sort of overhanging lip from the edge of the tegrnen 

 between the rays; it seems to be present in all the variations. 



This form persisted into the Hamilton, where it increased in size, 

 and underwent some striking changes in surface markings, while 

 retaining with thorough constancy the cliief distinguishing characters 

 of the type. This was described by Miller and Gurley as a variet\', 

 asperatus, but in view of the difference in horizon, it is better treated 

 as a species, and it will be listed as such under the Hamilton. 



Horizon and locality. — The type of D. ornatus is in Columbia Uni- 

 versity; and the species is from the Onondaga limestone at Columbus. 

 Ohio, and in western New York. 



DOLATOCRINUS ROTUNDUS, new species. 



Plate 5, figs. 12, 13. 



This species is founded upon a single specimen, of a type differing 

 from all others in having a perfectly round calyx, without angularities 

 or projections of any kind; the surface is smooth, and there is no 

 lobing, or depression, except a slight one for the column facet. It 

 has 10 arms: although surface preservation is good, pinnule openings 

 are not discoverable between the arm bases. The dimensions are 

 25 mm. high by 30 mm. wide, being slightly contracted verticallj^; 

 1 7 mm. of this height is from the base to the middle of the arm open- 

 ings, leaving the tegmen low in proportion to the total height. The 

 specimen is in good condition, and these characters must be accepted 

 as definite structures, there being no other species of which it can be 

 considered a variant. 



Horizon and localit;/. — -The type specimen came from the Onondaga 

 (Jeffersonville) limestone at the Falls of the Ohio River at Louisville, 

 Kentucky, below the hydraulic limestone. 



DOLATOCRINUS SPECIOSUS (HalD- 



Cacabocrinus spedosus Hall, 15th Rep. New York State Cab., 1862, p. 109 (137) 

 Dolatocrinus speciosus. Wachsmuth and Springer, N. A. Ciin. Cam., 1897, p. 323. 

 pi. 2fi. ligs. 4a, 6. 



Hall gave no figures of the several species described by him in- the 

 fifteenth report under Cacahocrinus, but this one was well illustrated 

 by Wachsmuth and Springer from a somewhat eroded New York 

 specimen answering the description. In form of calyx it represents 

 a type that might be called doubly conical, sloping both ways from 

 the zone of the arms, and truncated at the broad base, where the 

 width is about two-tliirds that at the arm level. The wide, rather 

 angular, outward slope of the sides from the plane of the base gives 

 a basin-shaped contour distinct from that of most of the other species 



I 



