TAXOCRINIDAE 377 



it is rather curious that its name and definition can scarcely be traced to a definite and authori- 

 tative origin, but must be deduced from somewhat complicated and contradictory literature. 

 Both, however, can in my opinion be placed upon a sound basis. 



The type, in its generalized facies, which is now taken to represent the whole Flexibilia 

 group, was clearly recognized by that keen observer, John Phillips, in 1841, when describing 

 his Cyathocrinus ? macrodactylus (Palaeozoic Fossils of Cornwall, etc., p. 29). From the 

 context it appears clear that it was the study of this species which suggested the idea of a new 

 generic group, which " unlike other Cyathocrinites and Poteriocrinites might be character- 

 ized by having the scapular, costal, and cuneiform arm base in one row and of one breadth " ; — 

 a feature which is one of the salient characters of the Flexibilia generally. Immediately fol- 

 lowing the description of the above-mentioned species he said : " On comparing this form 

 with Poteriocrinus ( ?) egertoni and Poteriocrinus nobilis [previously described by him] and 

 Cyathocrinus tuberculatus [of Miller], it appears that they are congeneric." For this group 

 he proposed the name Isocrinites, indicating the specific characters as " depending on the 

 number of plates in the costal, brachial, and digital series " ; and he listed the species as 

 follows : 



Isocrinus egertoni, to have seven costals. 



tuberculatus, three costals and three brachials. 



macrodactylus, four costals, five brachials, and six, ten, fifteen digitals. 



nobilis, four costals, four or five brachials, and four, etc., digitals. 



While proposing the name "Isocrinites," it is interesting to see that on the same page he 

 listed the species under "Isocrinus." 



It is important to note that the " costals " of Phillips included both radials and primi- 

 brachs of present terminology, for on p. 29, under C. macrodactylus, he said : " The pen- 

 tagonal supra-columnar joint is surmounted by five plates (pelvis of Miller), alternately with 

 which, and above them, are five rows of broad costal and scapular plates, four in each, the 

 last being cuneiform " ; — i. e., the fourth plate is the axillary ; hence there is a radial and 

 three primibrachs. 



Phillips's choice of the name Isocrinus was unfortunate, it being preoccupied by 

 Von Meyer in Agassiz in 1835 i 1 and the Austins in proposing as a substitute for it in 1843 

 Agassiz's name Cladocrinites [Chladocrinus] fared no better. Having discovered that this 

 name was preempted, they made another effort when preparing their Monograph on Recent 

 and Fossil Crinoids, which they began to publish in parts in 1843 ! an d on p. 66 of that work 

 (in a part which was not published until 1846) we find the name Enryatecrinus as a new 

 genus in which Miller's C. tuberculatus has been included. This was evidently left in the 

 text by oversight, as on a previous page (61) they use the name Taxocrinus for longidac- 

 tylus, one of the species which had been ranged under Cladocrinites in 1843 — thus showing 

 that they had already learned of Phillips's new name as promulgated by Morris. 



In 1843 Morris, in the first edition of his Catalogue of British Fossils, p. 59, published 

 the name Taxocrinus credited to Phillips, listing the species under it as follows : 



Taxocrinus egertoni. 



macrodactylus. 



nobilis. 



tuberculatus. 



There is no evidence of any publication or definition of the genus under this name by 

 Phillips, and the work of Morris must be taken as fixing its date and standing. No defini- 

 tion was given there, but from the names of the species it is sufficiently clear that the genus 

 was intended for the group previously defined by Phillips under Isocrinus. No type species 



1 Isocrinus, H. de Meyer (encore inedit), Mem. Soc. Nat. Neuchatel. I, 1835, p. 195. Isocrinus, H. von 

 Meyer (Letter to Bronn), Neues Jahrb. Min. 1836, p. 57; Mus. Senkenbergianum, 1837, p. 251. 



