20 BULLETIN 115, UNITED STATES NATIONAL MUSEUM. 



new and instructive forms were brought to light, and a valuable 

 addition was made to our knowledge of the prolific crinoidal faunas 

 of the interior continental basin. Most of the specimens were 

 obtained by Mr. Gurley through purchases from local collectors, 

 some of whom were not geologists, and sufficient care was not always 

 taken to determine the exact horizon from which they were derived; 

 so that in several instances the stratigrapliic position assigned to the 

 species in the published descriptions is not correct. This is notably 

 the case with some of the most conspicuous forms of the Louisville 

 area. 



Subsequently Mr. George K. Greene, the veteran collector at New 

 Albany, Indiana, on the Ohio River opposite Louisville, published 

 a series of pamphlets extending through the years 189S-1906, which 

 collectively formed the volumes entitled: Contribution to Indiana 

 Paleontology, for the purpose of illustrating his extensive collection 

 of corals and crinoids — the work upon the latter being intrusted to 

 Prof. R. R. Rowley, of Louisiana, Missouri. This resulted in the 

 proposal of 16 new species and varieties of Dolaiocrinus , likewise all 

 from the Louisville area. 



The type and another early species had been published by Lyon, 

 and seven others from New York, Canada, and Michigan by Hall, 

 Whiteaves, and Barris, respectively. Of those published by Wachs- 

 muth and Springer in their Monograph of the North American 

 Crinoidea Camerata in 1897, some had been anticipated by the descrip- 

 tions of Miller and Gurley while that work was going through the 

 press, and it is necessary for the correctness of the record that the 

 synonymy of these should be definitely stated. Two species from 

 Michigan were published by Miss Elvira Wood in 1904. I am 

 informed that at least two new species and as many varieties from 

 New York are to be published by the State museum; and I am 

 reluctantly compelled to swell the list by adding four new names 

 on my own account.^ 



Recurring again to the numerous Hamilton species published by 

 Miller and Gurley: In order to facilitate the describing of species, 

 they at the outset laid down as an ironclad rule that the number of 

 arms alone should constitute an invariable specific character, so that 



•The dilterences in the known crinoidal faunas of the several TIauiilton areas of the Middle Devonian 

 of this continent are very striking. At Louisville Dolatocrinus is the leading genus, followed by Megistn- 

 crinus, Nucleocrinus, Codastcr, etc., but no sign of M docrinus or of any Flexible crinoid; in Callaway 

 County, Missouri, Melocrinus occurs, and an Ichthyociinoid ot the genus Daclylocrinns, but no Dolatocrinus 

 or Mcgislocrinus; in Iowa Mcgistocrinus and ^f docrinus and a notable new Ichthyocrinoid, but no Dolato- 

 crinus in northern Michigan, Dolatocrinus, Mcgistocrinus, Nucleocrinus, and Codastcr, of species mostly well 

 differentiated from those of the Louisville area; in Wisconsin, Melocrinus closely similar to the Missouri 

 species, forms v.-hich also extend far to the north in the McKenzie Basin, Canada; in the last four areas, not 

 including the Canadian, species belonging to the Floxibilia occur, of diflforent forms in each. In western 

 New York and Ontario, Dolatocrinus and Mcgistocrinus closely related to the Louisville forms occur; but 

 in addition to these an extraordinary assemblage of other forms not i eprasentcd in either of the other areas, 

 which are soon to be dPsoril)ed in a Memoir bv the the New York State Museum. 



