362 SMITHSONIAN INSTITUTION 



Disregarding the doubtful Silurian species, this is the earliest of the genus ; it occurs in 

 the Hunsriick slates, about the middle of the Lower Devonian. The only species with which 

 it needs to be compared is T. rhenanus from the next higher formation in the same region, 

 and from that it is readily distinguished by its more slender proportions throughout. This 

 is well shown by the relative proportions of the lower brachials in the two ; in T. rhenanus 

 the IIBr are, height to width, 1 to 2.1 ; IIIBr 1.4 to 3 ; in T. sturtzii IIBr are 1 to 1.5 ; IIIBr 

 1.8 to 2. The specimens are found crushed very flat, in a dark pyritiferous slate which 

 adheres so closely to the fossils that it is only removed by chemical means, and structural 

 details are obscured. I have copied Follmann's figure of the type, and figured the best other 

 specimen known to me from the collection of Dr. B. Sturtz in Bonn. 



Type. In the Palaeontological Museum of the Rheinische Friedrich-Wilhelm's Uni- 

 versity at Bonn, Germany. 



Horizon and locality. Lower Devonian, Hunsriick slate; Bundenbach, Germany. 



Eutaxocrinus affinis (Miiller) 

 Plate XLIX, figs, p-10 



Taxocrinus affinis Miiller, Monatsber. Akad. Wiss. Berlin, 1856, p. 353; ibid., Abhandl. for 1856 [1857], 

 p. 244, pi. 1, figs. 1, 2. — Schultze, Mon. Echinodermen Eifler Kalkes, 1867, p. 34, pi. 4, figs. 2, 2a, b — 

 Beyrich, Monatsber. Akad. Wiss. Berlin, 1871, p. 43 (Transl. in Ann. and Mag. Nat. Hist., (4) VII, 

 p. 401). — Wachsmuth and Springer, Revision Palaeocrinoidea, pt. 1, 1879, p. 48. 



Eutaxocrinus affinis, Springer, Jour. Geology, XIV, 1906, p. 519. 



Type of the genus. 



A medium-sized species. Crown short, turbinate, nearly as wide as high 

 at level of IIIBr in the principal specimen, which is somewhat compressed ver- 

 tically, being 30 mm. high, 27 mm. wide; base, 7 mm., in natural contour prob- 

 ably about 1.5 high to 1 wide. In the type, which is normal as far as preserved, 

 the calyx shows height to width at top of IBr, 1 to 1.5, and spread from base of 

 1 to 3, most of this being opposite IBn by reason of the large iBr. Side outline 

 slightly convex. Arms broad and flat, diminishing rapidly at the bifurcations 

 beyond the IIBr, and infolding about the fourth; sutures broadly arcuate be- 

 yond IBr. Anal tube fairly strong, composed of elongate plates, resting on 

 right shoulder of post. B. iBr present. Surface smooth. 



IBB low, appearing as a thin ring above the column. BB small, short, with 



obtuse salient angles, except the posterior one supporting the anal series. RR 



small, almost quadrangular; shorter than either IBr, and little more than half 



the width of the axillary; deeply beveled at the lateral margins. IBr rapidly 



widening upward, axillary twice as wide as high. IIBr 4, almost as large as the 



first IBr, and three times as wide as high; higher Br diminishing in width by 



half, but less in length, not meeting above iBr, but leaving long and wide areas. 



iBr one large, opposite IBn, thick, convex or projecting above outer surface of 



adjacent brachials; areas above probably filled by perisome. 



The most striking character of this species is the thick, rounded interbrachials, which 

 resemble blunt pegs standing up between the bases of the rays, unlike those of any other 

 known species ; the distal margins of these are rounded, indicating that no solid plates fol- 

 lowed them, although the spaces above and between the higher divisions are ample. The 

 whole aspect of the crinoid is different from that of the other Devonian species, as is appar- 



