1885.] NATURAL SCIENCES OF PHILADELPHIA. 231 



in describing species " has given rise to the expression " " under- 

 basals obsolete," " which everyone must concede is ridiculous." 

 Is the phrase " subradials unrepresented " or " obsolete " less 

 ridiculous to Mr. Miller, especially considering that those plates 

 are interradial in position ? He further says : " The policy 

 of changing the nomenclature may well be doubted." "The 

 claim is made that the change will bring the nomenclature used 

 in denning recent Crinoids in conformity with that used in 

 describing fossils, but as long as this is doubted, it is better to 

 adhere to the established or prevailing methods of description." 

 We cannot see what this has to do with recent and fossil Crinoids. 

 If it is right in the one group it is right in the other, for they are 

 built fundamentally on the same plan. The question is simply 

 this: In Crinoids with a dic} T clic base are the plates of the 

 proximal ring or those of the inner ring the homologues of the 

 basals in monocyclic Crinoids ? If the latter is the case, and we 

 think it has been most satisfactory proved by Carpenter, the 

 term basals should be applied iu all cases to the interradial ring, 

 no matter what the " prevailing methods " have been heretofore. 

 Certainly Mr. Miller would not call the anus of fossil Crinoids 

 the mouth, for the reason that it was called so by the most 

 eminent earlier writers. Besides, the term " subradials " is illog- 

 ical, as the plates to which the name was applied are interradial 

 in position. 



In the Neocrinoidea,the basals, with the exception of Hyocrinus, 

 consist of five pieces, and in comparatively few cases an anclry- 

 losis took place. In the Palseocrinoidea, however, among Crinoids 

 with a monocyclic base, anchylosis of two or more of its plates is 

 the rule. We find five basals only in Silurian genera, but asso- 

 ciated with one genus having four. Four basals do not prevail 

 beyond the Devonian, and apparently not bej^ond the middle 

 portion of it. Three basals commence in the Upper Silurian and 

 continue to the close of the Subcarboniferous, while two basals 

 are found exclusively in the latter epoch. 



The number of underbasals is five, with but few exceptions. 

 Xenocrinus has four ; the Ichthyoci'inidae, Gissocrinus, Lecythio- 

 crinus, Tribrachiocrinus, three ; while in the Carboniferous 

 Stemmatocrinus the underbasals form a perfectly anch} r losed 

 disk. The latter was taken by Carpenter to be a top-stem 

 joint, an interpretation which we cannot accept, but as we 



