Lower Palceozoic Grinoids of Bohemia. 1 15 



species or even a single individual ; with the anal area 

 distinguished only, and that slightly, by its greater width 

 and greater number of plates ; with arms bifurcating fairly 

 regularly from 3 to 5 times (possibly more), and composed of 

 simple brachials, which in the free portions are pinnulate and 

 either uniserial (especially in the proximal region) or alterna- 

 ting (especially in the distal region), but not biserial in any 

 authentic specimen ; with both the primibrachs, all the 

 secundibrachs, which are numerous, and the more proximal 

 tertibrachs loosely joined to those of adjacent rays by a pave- 

 ment or network of plates. 



A very careful study of a large number of specimens 

 belono-ino- to this variable genus has led the authors to 

 separate them, according to the ornament of the cup-plates 

 and especially the interbrachial network, into the following 

 species and varieties, which form a closely connected series : 

 Scyphocrinus subornatus; S. excavatus, var. Zenonis, var. 

 Schlotheimi , var. typica, va.r. Schroeteri ; S. decoratus. Except 

 S. excavatus, all these names are new ; the name S. subornatus 

 is indeed ascribed to Barrande, but apparently only on manu- 

 script evidence. One misses the familiar S. elegans, Zenker ; 

 but this yields to the name Pentacrinites excavatus, which 

 Schlotheim in 1820 applied to pi. iv. fig. 2 of J. S. Schroe- 

 ter's ' Vollstandige Einleitung &c.,' 1778, in which work 

 the honour of original discovery is ascribed to F. Zeno, 

 Professor at Prague University. The case is, however, no 

 clearer than usual with these old names. It is admitted that 

 the details given by Schroeter and Schlotheim do not indi- 

 cate definitely any one even of the species, much less one of 

 the varieties, distinguished by the present authors. The 

 name excavatus has by no previous writer been resuscitated 

 or applied to Scyphocrlnus. One would therefore be inclined 

 to let it rest and to adopt S. elegans, Zenker, did not Messrs. 

 Waagen and Jahn assert their inability to find in either 

 figures or description of Zenker the characters absolutely 

 necessary for any decision as to which of their species may 

 claim the name elegans. Since, moreover, not one of the 

 numerous writers on this genus has attempted to give pre- 

 cision to the specific name, the way seems clear for the 

 present authors to exercise their free choice. Therefore they 

 make the loosely defined elegans a synonym of the loosely 

 defined excavatus, and adopt the older term for their largest 

 species. The chief objection to this proceeding is that 

 one can after all determine the species to which Zenker 

 applied the name S. elegans. In the very words of the 

 volume before us : u l'espece de Zenker differe notablement 



