EXPLANATION OF PLATE. 



Cleioceinus regius Billings. 



Ordovieian, Trenton Limestone. Ottawa, Canada. 



Fig. 1. The type specimen ; from the original of Fig. la, PL V., Canadian Organic re- 

 mains, Decade IV. View from right posterior interradius. The lateral faces 

 of the anal series can be seen to the left, where they are at the thin edge 

 of the flattened calyx; the bases of several arms are also shown. Specimen 

 A of text. 



2. Opposite side of same specimen. (Billings's Fig. 1 b shows only the basal portion 



of this view.) 



3. Another specimen, showing calyx, pinnulate arms and stem ; right posterior 



view : composed of (a) crown from the second primibrach up, with a few 

 plates broken away at either side, — not figured by Billings ; (b) the two lower 

 ranges of calyx plates visible exteriorly, and part of the stem attached, — being 

 the original of Billings's lc; (V) the next succeeding portion of the stem; 

 (<!) another portion of the stem near the root; (e) the terminal part of the 

 stem, with spreading root for attachment to other objects, — Billings's 1 y. 

 With these are four other intermediate fragments — a portion next to the root 

 being wanting — the whole composing a stem over ten inches long, increasing 

 in diameter near the root, and the columnars becoming thinner; (/) trans- 

 verse section of this stem about an inch below the calyx, (/is X 2.) Speci- 

 mens B, C, D, of text. 



4. Posterior view of 3 b, showing the posterior basal and first anal plate. 



5. Left lateral view of 3 b ; the left anterior basal removed, showing the dicyclic 



base. 



5a. Obliquely vertical view of same specimen; showing the interior of the calyx, 

 the five infrabasals, and how the basals and radials, at the same level, hang 

 on to the outer side of the infrabasals, instead of the basals resting upon their 

 upper faces and the radials in turn upon the basals. The large axial canal is 

 seen in the middle. X '2. 



5b. A slightly less vertical view of the same structures, in greater detail. The 

 maimer in which the basals and radials overhang the column, and also the lip- 

 like groove at the upper edge of the infrabasals, are well shown here. The first 

 anal plate, seen to the right, is slightly displaced by pressure. X 4. 



6. Diagrammatic vertical section laterally across 5 b, from radial to opposite basal, 



showing the relative positions of the plates. 



7. Diagram showing relative position of calyx plates, for comparison with diagram 



in Revision of the Palaeocrinoidea, Pt. III., PL IX., Fig. 5. 



8. Diagram of right posterior ray and anal series, from specimen A (Figs. 1 and 2 



supra). The relation of the eight brachial series and arms to the adjacent 

 and intervening fixed pinnules is shown. 



9. Some calyx plates of specimen A, showing the pitting or crenulation of the 



articulating edges. X 2. 

 10. Part of arm and pinnules. X 2. 



