■88 SMITHSONIAN INSTITUTION 



PLATE XLI 

 (All figures natural size except where otherwise stated) 



^ PAGE 



Figs. 1-2. Dactylocrinus oligoptilus ( Pacht) 310 



Fig. in. The principal type specimen, left posterior view ; after Pacht, pi. i, fig. i. Shows the anal 

 structures, equal ray divisions and small ramules on every third or fourth Br. Loca- 

 tion of specimen unknown. Costijetsi,-bank of river Schelon. 



lb. Base of same, showing concavity with some proximal columnals attached, entirely 

 covering IBB. 



ic. Diagram of calyx; after Pacht. 



id. Cross-section of base, showing depth of concavity, and position of IBB and BB ; after 

 Pacht, pi. I, fig. 2, slightly corrected. X 4 . 



le. Central opening at inner floor of base; from Pacht's fig. 2, showing IBB, and triangular 

 funnel leading to axial opening. X f- 



2. An axillary IBr, from a smaller cotype, to show surface ornament. X 2. Same locality. 

 Upper Devonian. Pskow, Russia. 



Figs. 3-4. Dactylocrinus beyrichi (Dewalque in F'raipont) 311 



Fig. 3. The type, anterior view ; after Fraipont. Ray divisions equal ; the figure erroneously 

 represents a ramule on every brachial. University of Liege. 

 40. Larger specimen from same locality, left anterior view. Shows the arm structure in 

 detail, with ramules from every second brachial ; and the sharply concave base with a 

 few tapering columnals resting in it. Author's collection. 

 4b. Posterior view of same, showing anal structures. 

 Upper Devonian. Senzielles, Belgium. 



Figs. 5-6. Dactylocrinus excavatus (Schultze) 308 



Fig. Sa. The type, original of Sclfultze, pi. 7, fig. 2; anterior view. Has no interbrachials. Mus. 



Comp. Zool. Kerpen, Germany. 



Sb. Posterior view of same, showing post B and some small anal plates ; ramules at intervals 



of 3 or 4; no iBr. 

 Sc. Basal view of same, showing deep cavity, involving part of RR. It is 12 mm. deep from 



level of the curved edge. 

 Sd. Diagrammatic cross-section, to show the depth of basal cavity, with IBB at level of 



IIBrj; and the relative position of BB and RR. X |« 

 6a. Specimen with interbrachials ; type of Schultze's var. interscapularis, pi. 7, fig. 3 ; r. post. 



interradial view. Mus. Comp. Zool. Steinfeld, Eifel, Germany. 

 6b. Posterior view of same. 

 6(7. Basal view of same, showing deep cavity. 



Middle Devonian. Eifel Mountains, Germany. 



Figs. 7-9. Dactylocrinus eoncavus (Rowley) 309 



Fig. 7a. The principal type specimen, original of Rowley's Aristocrinus eoncavus; r. post, interradial 

 view ; showing large iBr, smaller size of inner ramus, and ramules at intervals of 

 about 3. Coll. Prof. R. R. Rowley. 

 yb. Posterior view of same, showing arrangement of anal plates. 

 . Jc. Basal view, showing broadly rounded cavity, with IBB hidden by columnals; axial 

 canal radial. 

 8a, b, c. Anterior, posterior and basal views of smaller cotype ; a much younger specimen, 



with ramules less developed. Coll. Prof. R. R. Rowley. 

 9. Mature specimen with all anal plates intact; posterior view. Author's collection. 

 Hamilton Gr. ; Middle Devonian. Calloway County, Missouri. 



