TAXOCRINIDAE 371 



This species is proposed upon a single specimen from the New York Chemung, being an 

 impression from a natural mould in the collection of the late Professor James Hall now in 

 the University of Chicago. In its peculiarly large and robust habit it is unlike any other of 

 this genus, and looks more like a specimen of Onychocrinus ramulosus. This resemblance 

 is heightened by the presence of two or three irregular ramule-like arm-branches, but in gen- 

 eral structure the arms are in nowise like those of that genus. Lack of knowledge of the anal 

 structures makes the generic position of the species uncertain. 



Type. University of Chicago. 



Horizon and locality. Upper Devonian, upper beds of the Chemung group ; Bingham- 

 ton, New York. 



Eutaxocrinus fletcheri (Worthen) 

 Plate L, figs, n-ip 



Taxocrimts. fletcheri Worthen, Bull. I, Illinois St. Mus., 1882, p. 31 ; Geol. Surv. Illinois, VII, 1883, p. 308, 

 pi. 30, fig. 2. — Wachsmuth and Springer, Revision Palaeocrinoidea, pt. 3, 1886, p. 144; Geol. Surv. 

 Illinois, VIII, 1890, p. 197, pi. 15, figs. 6, 9. 



A medium-sized species. Crown rather short, robust, turbinate almost to 

 the top; greatest width in adult specimens about the fourth or fifth bifurcation, 

 where height to width is about 1.4 to 1. Calyx proportionally slender with a 

 broad base, side outline straight; height to width at I Ax, i to 1.4; spread from 

 base, 1 to 1.4. Arms robust below, branching with short divisions five times 

 before infolding in adult specimens, three times or less in young; diminishing 

 rapidly with each bifurcation to slender finials; sutures arcuate. Anal tube 

 small, bordered by finely plated perisome and merging into it distally, composed 

 of elongate plates; iBr present. Column very thick, flush with base and en- 

 larged next to calyx, narrowing in proportion of 1.4 to 1 in about 15 mm., with 

 very thin columnals in the conical part ; below that alternate columnals becoming 

 longer and rounder ; it decreases in diameter distally, and apparently terminates 

 in a narrow end without root. Dimensions : crown in maximum specimen, 

 height, 34 mm. ; width, 20 mm. ; base, 9 mm. Average of 4 adults : height, 

 29 mm.; width, 19 mm.; base, 9 mm. Of a young specimen: height, 12 mm.; 

 width, 9 mm., base, 4 mm. Of column in a medium specimen : diameter at 

 calyx, 8.5 mm.; at end of conical enlargement, 6 mm.; in middle, 5 mm.; near 

 distal end, 2.7 mm.; length of 23 ossicles in conical part, 15 mm. (=.6 mm. 

 each) ; total length to near the probable termination, 16 cm. 



IBB low, resembling a thin columnal. BB fairly large, short and broad 



with obtuse angles. RR and IBr of nearly the same size and form, more than 



twice as wide as high. IIBr 3, sometimes 2, shorter than and nearly as*wide as 



the IBr. IIIBr much smaller, 4 in outer and 3 in inner ramus; followed by 



rapidly diminishing branches with 6, 7, 8 brachials in the outer ramus to the 



VIIBr, which has 8 in one specimen. iBr spaces very narrow, with 1 to 3 small 



plates between the rays, and occasionally similar elongate ones in the first axil. 



This species and the next are the only Carboniferous representatives of the genus, and 

 mark its end in the earliest formation of that epoch. The description is made from a fine 

 series of well-preserved specimens, eight of them entirely free from the matrix, and three 



