Description of Two New Genera and Eight New Species. 37 



supports an arm, while the two lower rest, one of them on one of the 

 upper processes of the azygous subradial, and the other upon a process 

 of the right anterior subradial, and it is probable that the other rays 

 are constructed and situated in nearly the same manner. The right 

 arm divides above the fourth plate. The number of primary radials in 

 the other aims was not certainly ascertained. The spaces between 

 the arms is occupied b}' numerous small stellate plates. 



Prof. Billings was an accurate observer, reliable in ii is statements, 

 and has not been excelled in his knowledge of the structure of 

 Silurian crinoids b}- an}- American palaeontologist. The characters 

 that he observed in the genus Beteocrinus can not be set aside as er- 

 roneous, until some one, from an examination of specimens of B. stel- 

 laris, shall have pointed out mistakes, and even then, if the genus 

 stands, B. stellaris will be the type. 



Up to this time, no crinoid possessing the characters ascribed to 

 this genus has been found in the Hudson River Group of this localit} r . 

 The well-developed basals, large subradials and peculiar azygous sub- 

 radial, with its elevated ridges extending to the primary radials on 

 either side, and the bifurcation on the fourth primary radial, are im- 

 portant parts of the structure, beside, it is distinguished for its 

 reticulated appearance, owing to the large connecting ridges, extend- 

 ing from the basals to the subradials, and from the latter to the pri- 

 mary and secondaiy series, and the depressed interradial spaces occu- 

 pied by small stellate plates. 



Messrs. Wachsmuth and Springer have disposed of the genus Beteo- 

 crinus, of Billings, by saying that it "was described from imperfect ma- 

 terial, and altogether misunderstood by its founder," and then proceed- 

 ing to make Glyptocrinus onealli the type of the genus Beteocrinus. 

 This is too open a violation of the rules of nomenclature to receive 

 much consideration, beside their separation of the species under this 

 genus, and that of Glyptocrinus, shows, to one familiar with the struc- 

 ture, such a cross-mixture of characters as to indicate a want of 

 general acquaintance with the genera and species. 



Glyptocrinus sculptus, n. sp. 



Plate I, fig, 2, natural size. 



Bod}' somewhat urn-shaped, nearly as wide as high, sides rounded 

 below, forming an angular, cup-shaped base. Interradial and inter- 

 secondary radial areas flattened and slightly depressed below the 

 radial ridges, giving it a marked angular outline. 



