3/8 SMITHSONIAN INSTITUTION 



was indicated by Morris, and no guide to this is furnished by the order in which the species 

 are mentioned, which is purely alphabetical. Neither did Phillips designate any type among 

 his original list of species under Isocrinus. It has been assumed by some authors that 

 /. egertoni, because standing first in that list, should be taken as the type of the genus. But 

 without any indication by the author of such purpose in the arrangement this fact is by no 

 means so important as the fact that the species which Phillips personally studied at the time 

 he proposed the genus, and the consideration of which evidently induced the recognition of 

 the generic type, was /. macrodactylus. 



The first author to treat of Taxocrinus after its publication by Morris was M'Coy, who 

 in 1844 (Carb. Foss. Ireland, p. 178) gave a generic diagnosis, and out of all the species 

 named by Phillips selected T. macrodactylus for a full specific description, following it by a 

 new species of his own. This was accepted as conclusive by that careful and judicious paleon- 

 tologist F. B. Meek, who in connection with Worthen in 1866 (Geol. Surv. Illinois, vol. 2, 

 p. 271) said: 



"As M'Coy, who first followed Phillips in the use of the generic name Taxocrinus (1844), evidently 

 viewed T. macrodactylus as the typical form of the genus, it would, according to the most generally 

 accepted rules of naturalists, become the type of the genus for all time to come." 



This statement was made in the course of an elaborate discussion of the relations of the 

 genera Taxocrinus and Forbesiocrinus, and it is the first formal designation of the type 

 species of Taxocrinus to be found in the literature. Therefore, under Article 30 of the 

 revised International Code as interpreted by the leading authorities, T. macrodactylus 

 becomes the type by subsequent designation. 



Of the other species assigned to the genus by Phillips, T. tuberculatus has been removed 

 to constitute the type of T em-no crinu's; T. egertoni may belong to Onychocrinus, but is not 

 well understood and the type specimen cannot be found. This leaves only T. nobilis, which 

 goes readily with T. macrodactylus as a good representative of the genus as now restricted. 



Pacht in 1852 (Dimerocrinites oligoptilus, p. 7), in ignorance of Phillips's proposal of 

 Taxocrinus, and mistaking entirely the nature of his genus Dimerocrinites, referred the 

 species nobilis and tuberculatus to the latter. 



Roemer in 1851, and subsequently in Bronn's Lethaea Geognostica (1852-54), rejected 

 Taxocrinus, and referred all its species to Cyathocrinus — a course which has not been fol- 

 lowed by any other author. 



De Koninck and Le Hon in proposing their genus Forbesiocrinus in 1854, undertook to 

 limit Taxocrinus to species without any interradials (interbrachials) ; but their proposal was 

 rejected by subsequent authors, such as Schultze, Meek and Worthen, and Wachsmuth and 

 Springer, in the course of extended discussions. On the other hand the presence of inter- 

 radials as a generic character was expressly stated in the same year by M'Coy as separating 

 the genus from Ichthyocrinus. 



The genus has been recognized in the sense of Phillips by authors generally since 

 Roemer's time, with a tendency sometimes to enlarge, and again to restrict, its limits. 

 Schultze (1866) found scarcely enough ground to distinguish Forbesiocrinus from it; Meek 

 and Worthen (1866) proposed to include that genus, and even Onychocrinus, as mere sec- 

 tions under Taxocrinus; Beyrich (1871) expressed the opinion that these genera "can only 

 be retained if Taxocrinus be limited to those species in which the first division of the radii 

 takes place on the third joint, while four primary radial segments are characteristic of 

 Forbesiocrinus." Pie meant the " third joint " including the radial, i. e. IBr 2 , and his plan 

 cannot stand because it thus necessarily excludes the type species, T. macrodactylus. 

 Wachsmuth and Springer in 1878 went beyond all others in the direction of consolidation, 

 concluding that both Taxocrinus and Forbesiocrinus should be considered at the most as 

 only subgenera under Ichthyocrinus. A better understanding of the whole group resulting 



