248 FREDERICK W. SARDESON 



nals, nearly corresponding in circles. They are found in the upper 

 part of zone No. 4 (Stictopora bed), where specimens figured were 

 found, and in the base of zone No. 5 (Fucoid bed) of the Galena- 

 Trenton stage at St. Paul, Minn. The only probable related calyx 

 is that of Eucheirocrinus punctatus (Ulr.) which has the same range, 

 and although pieces of stem one-half inch long attached to them have 

 oval rings yet, in view of the great differences known to mark Crinoidal 

 columns, the lower part of the same might be the one under considera- 

 tion. 



Podolithus dendrocrinus n. sp. 



(Figs. 24, 25, 26) 



This species comprises roots in which the discoid or conical form 

 is concealed, but in which the structure remains. They occur attached 

 to hard surfaces with one to five simple or branched radicles of various 

 lengths. Fig. 24 is of the largest specimen. One of its radicles 

 curves downward. The radicles or lobes are smooth and quite 

 round, excepting the under side by which they are attached. Seen 

 from the upper side they consist of narrow transverse rings, but a 

 thin-section shows that these are interrupted by the fixing-plate 

 which unites with them by suture. Fig. 25 shows the thin-section X4. 

 The section is cut across three lobes, a, b, ^c, each of which attaches 

 to the same MonticuHporoid stock. Fig. a cuts obUquely, striking 

 two plates above, while b cuts a bifurcation. The fixing-plate in c 

 penetrates a cell of the MonticuHporoid at that point. Compare 

 Fig. 18. The lumen is represented in black. 



The stem-scar is preserved in several cases and clearly shows a 

 stellate lumen and radiate Ugamental scars. Certain cylindrical 

 Crinoid colunms are found in the same strata and are easily matched 

 with these though generally larger in size. Fig. 26 represents the 

 end of such a column X2 without the radiating striae, about 75 in 

 number, which are omitted. It shows the lumen and ten distinct 

 canals which run in the joint and in part thence through the segment. 

 On the outer surface, the canals appear as distributed pores. The 

 same canals are seen at the stem-scar of the roots, but I cannot find 

 them lower on the disk or its lobes. 



These roots and colunms occur rarely in zones Nos. 4, 5, and 6, 

 of the Galena-Trenton stage. Figs. 24, 25, 26, are of specimens 



