300 PROCEEDINGS OF THE ACADEMY OP [1881. 



1862. Dolatocr. glyptus var. intermedins Hall. (Cacaboorinus). 15th Rep. N.York 



8t. Cab. Nat. Hist., p. 141. Hamilton gr. Livingston Co., N. Y. 

 1857. Dolatocr. lacus Lyon. (Type of the genus). GeoL Rep. Ky., iii, p. 482, PI. 4, 



fi,i;s. 2 a, b, c. Encrinal limost. Beargrass quarries, Louisville, Ky. 

 1862. Dolatocr. lamellosus Hall. (Cacabocr. lamellosus). 15th Rep. N. York St. Cat. 



Nat. Hist., p. 141 ; DolUocr. lameUosus S. A. Miller, Cat. Pal. Foss, p. 72. 



Western N. Y. Upper HeMerbcrg gr. 

 1862. Dolatocr. liratus Hall. (Cacabocr. liratus). 15th Rep. N. York St. Cab. Nat. 



llist., p. 1.39; Dolatocr. liratus S. A. Miller, Cat. Pal. Foss., p. 72. Western 



N. Y. Hamilton gr. 

 1862. Dolatocr. liratus var. multilira Hall. (Cacaboorinus). 15th Rep. N. York St. 



Cab. Nat. Hist., p. i;'>9. Hamilton gr. Western N. Y. 

 1869. Dolatocr. Marshi Lyon. Trans. Am. Philos. Sec, vol. 13, p. 461, PI. 27, 



figs, n, 1,2. Upper HelJerberg gr. Falls of the Ohio. 

 1862. Dolatocr. speoiosus Hall. (Cacabocr. speciosus). 15th Rep. N. Yoik St. Cab. 



Nat. Hist., p. 137; Dolatocr. speciosus S. A. Miller, Cat. Pal. Foss., p. 72. 



Upper Helderberg. Schoharie, N. Y. 

 1862. Dolatocr. Troosti Hall. (Cacabocr. Troosti). 15th Rop. N. York St. Cab. 



Nat. Hist., p. 138; Dolatocr. Troosti S. A. Miller. Cat. Pal. Foss., p. 72. 



Hamilton gr. Western N. Y. 



Subgenus STEREOCRINITS Barris. 

 1878. Proceed. Davenport Acad. Nat. Sci., vol. 11, p. 282. 



Stei'eocrinus in general form, mode of ornamentation, and in the 

 construction of tlie plates, resembles the simpler form of Dolato- 

 crinus. It differs from it in having two, instead of 3 X 5, primary 

 radials, and the basal plates, although closely anchylosed, dis- 

 tinctly divided into three pieces. 



Through the kindness of Rev. Dr. Barris, we examined a large 

 number of specimens from Davenport, and became satisfied that 

 the reduction in the number of radials is not accidental, but a 

 constant character, which extends to more than one species. 

 Other specimens have since been found by Dr. Barris in the Lake 

 Superior region, which confirm this opinion. The upper radials 

 in Stereocrinus are of the same size, and nearly of the same form, 

 as the second and third radials combined in Dolatocrinus, and 

 this suggests a modification from the two pieces in the one, to a 

 single plate in the other. It is very possible that in Dolatocrinus 

 the two pieces were united by syzygie,^ while in Stereocrinus 

 they became perfectly anchylosed. 



' In our general remarks upon the Actinocrlnldaj, we have suggested 

 that probably in genera, in which the second radial is qviadrangular and 

 transversely arranged like in Batocriims and Dolatocrimis, this plate i-epre- 

 sents a mere hypozygial joint, which with the axillary plate forms a syzygie. 



