TAXOCRINIDAE 399 



several plates in the second axil, usually arranged longitudinally, and occa- 

 sionally one in the third, only separating the ray divisions by a narrow angle. 

 Anal tube narrow, composed of elongate plates, bordered on either side by 

 rather weak perisome which readily breaks down, so that rarely are more than 

 two or three tube plates found intact in the best preserved specimens ; margins 

 of posterior rays facing tube rounded, and without sutural faces. Column 

 large and long, composed near the calyx of extremely thin columnals, varying 

 progressively from 4 to the millimeter in young specimens to 3 and 2.5 to the 

 millimeter in mature (Pis. LVI, figs. 10, 8, 5; LVII, figs. 1, 2) ; these continue 

 with slightly diminishing diameter for a short distance — 2 mm. in young to 

 about 15 mm. in mature — when the column suddenly and abruptly contracts 

 1 to 2 mm. ; here somewhat longer columnals begin to be interpolated and 

 continue until near the distal end. Some of these slightly project and their 

 edges are studded with small cogs or teeth (PI. LVI, figs. $b, 6) ; in some 

 specimens these denticulate columnals occur at regular intervals (PI. LVII, 

 fig. 2), while in others they are closely crowded together so that each columnal, 

 or every other one, appears to be of this character (Pis. LVI, figs. 30, b; 

 LVII, fig. 1). The column near the distal end tapers to a fine, branched root, 

 with a few very strong cirri in the lower part (PI. LVI, fig. 3&) : in young 

 specimens it regularly tapers distally from the point of contraction. Column 

 of a mature specimen about 480 mm. (20 inche-s) ; length of proximal enlarged 

 part in mature specimen, 15 mm., in young, 2 mm.; diameter in mature speci- 

 men at top of enlargement, 8.5 mm. ; at bottom, 7 mm. ; below enlargement, 

 5 mm. ; in a young specimen with enlarged part 2 mm. long the diameter at top 

 of enlargement is 2.7 mm.; at bottom, 2 mm.; and below, 1.5 mm. 



This is the widest known species, not only of Taxocrinus but of the entire Flexibilia 

 group. Next to Platycrinus hemisphericus it is one of the most abundant species at the 

 celebrated Lower Carboniferous locality of Crawfordsville, Indiana, and during the last 

 fifty years has been distributed among the principal museums of the world. It is singular, 

 therefore, that it should not have been described at an early day along with the other abun- 

 dant crinoids of that locality, and that, although often mentioned and figured, it should 

 remain for me at this late day to bring to light out of a mass of confusion and misunder- 

 standing the name by which under the rules of nomenclature it must be known. The species 

 is known in collections the world over under one of two names, viz., Taxocrinus (or For- 

 besiocrinus) multibrachiatus, and Taxocrinus (or Forbesiocrinus) meeki. In the early 

 collections made by Worthen, Corey, Hovey, Bradley, Bassett, Braun and others, it was 

 labelled Forbesiocrinus meeki upon the authority of Hall, whose species of that name was 

 founded upon a very imperfect specimen without the arms preserved which was found in the 

 lower part of the western Keokuk on the Mississippi River, and which moreover does not 

 belong to Taxocrinus. That specific name accompanied the specimens of the Crawfordsville 

 species into most of the European and many of the American collections. Good figures of a 

 characteristic specimen of it were published by Quenstedt in 1885 (Handb. Petref., vol. 4, 

 p. 946, taf. 75, figs. 24, 25) under Forbesiocrinus; and by Von Zittel in 1895 under Taxo- 

 crinus (Grundziige Pal., p. 138, fig. 273). 



