Hambach —Revision of the Blastoideae. 31 



the specimens shows remarkably well the genital openings, 

 ten in number, but no perforation of the deltoid piece as we 

 find in G. norwoodi. From the foregoing it will be seen that 

 our most distinguished palaeontologists, Hall, Shumard, 

 Meek, Worthen, and others were very well acquainted with 

 Pe,ntremitts granulatus Roemer = Granatocrinus cidariformis 

 Troost, but from all appearance, they bestowed very little 

 attention upon the morphological conditions of this species. 

 Their main object for consideration seems to have been the 

 general form and appearance. If this had not been the case, 

 one can hardly perceive how Shumard, Hall, Meek and others 

 could have grouped species together in such a way as they 

 have done. If it was necessary to remove Pentremites 7ior- 

 woodi from the true genus Pentremites on account of its dif- 

 ference in structure, it was equally necessary to separate it 

 from Troost' s Granatocrinus because Pentremites norivoodi 

 differs as much from one as from the other. 



The same uncertainty is manifested in all the later classifi- 

 cations as will be seen from the following abstracts : Zittel, 

 Handbuch der Palaeontologie, Band I., p. 434, gives it as 

 follows : — 



*' Gattung, Granatocrinus Troost. Elliptisch, eiformig 

 oder kugelich. Kelch wie bei voriger Gattung zusammen- 

 gesetzt, aber B. [Basalstiicke] klein, eingesenkt, seitlich 

 nicht sichtbar. Gabelstiicke verhaltnissmassig klein, etwa 

 zur halben Hohe reichend. Deltoidstiicke gross. Psuedo- 

 ambulacralfelder schmal, linear, bis zur Basis des Korpers 

 herablaufend. Kohlenkalk. Gr. ellipticus, norwoodi, etc.'* 

 But one of the type specimens shows just the reverse, i. e., 

 G. norwoodi. We see here that the most characteristic 

 part, i. e., the nature and construction of the genital open- 

 ings, is not considered, whereas great stress is laid upon all 

 features of a more general character. 



Hoerne's definition, Elemente der Palaeontologie, p. 

 128, is:— 

 **GRANATOCRINus Troost. Kelch wie bei Pentremites zu- 

 sammengesetzt, mit sehr kleinen Basalia, welche seitlich 

 nicht sichtbar sind, auch die Radialstiicke sind klein und 



