32 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



EXPLANATION OF PLATES 



Unless otherwise stated, all figures are natural size, and all the specimens 

 are in the author's collection in the United States National Museum. 



PL-^T'^ ^ PAGE 



Myxocrinus boletus Schultze 24 



Figs. I, 2, 3. Right posterior, basal, and ventral views of specimen from 

 Priim; showing the knob-like basal ring (here completely 

 anchylosed) ; the relatively large size of the three smaller ra- 

 dials, their indentation at the upper corners adjoining the larger 

 plates; food grooves for 16 arms, and the slightly elongate, 

 openings for the corresponding dorsal canals at the arm facets ; 

 the raised process on r. post. R. is well shown. X 3- 

 4, 5, 6. Similar views of a smaller specimen from Kerpen ; show- 

 ing the same features as the last, but with 15 grooves, and basal 

 ring unequally divided by two well-marked sutures. X 3- 

 7, 8, 9. Similar views of a detached basal ring from Nollenbach, 

 divided by two distinct sutures and a third faint one ; it shows 

 the completely solid nature of these plates, enclosing no cavity, 

 but rising on the upper side into a low pyramid, symmetrically 

 pentagonal, pierced by the central axial canal, and three dorsal 

 canals at each of the peripheral sides. 

 ID. Generic diagram based upon the foregoing specimens. 



All Middle Devonian, Eifel limestone; Eifel, Germany. 



Mycocrinus conicus n. sp 25 



II, 12, 13. Right posterior, left anterior, and ventral views of type, 

 from Nollenbach ; showing the relatively higher and more coni- 

 cal basal ring, obscurely divided, and food grooves and dorsal 

 canals for 11 arms. X 3- 

 Same horizon and area as last. 



Catillocrinus turbinatus n. sp "2^ 



14. A nearly complete crown free from matrix, with 34 arms and 



proximal enlargement of stem; posterior view, showing anal 

 plate, basal ring about one-fourth the height of cup, and a very 

 distinct suture under r. post R. X f . 



15. Left anterior view of same. X t- 



16. A dorsal cup, showing the turbinate form, as contrasted with the 



hemispheric contour of C. tenncsseensis; left anterior view. 

 X2. 



17. Dorsal view of same; the obtusely angular area appearing at 



the middle of base corresponding to the infrabasal cone in speci- 

 mens of C. tennesseeae is pushed inward to a different level, at 

 which the lumen for the axial canal shows ; no sutures can be 

 seen in this, nor in the basal ring surrounding it. X 2. 



Mississippian, New Providence shale; Button Mould Knob, 



Kentucky. 



