522 FRANK SPRINGER 



Anisocrinus Angelin 



Fig. 9. — A. interradiatus Ang. Upper Silurian, Gotland, Sweden. Posterior, 

 view; from original to Angelin, XXII, 18. 



Fig. 10.—^. angelini W. and Sp. Upper Silurian, Gotland, Sweden. Pos- 

 terior view. X 2. 



Fig. II. — A . greenei M. and G. sp. Upper Silurian, Louisville, Ky. Posterior view. 



Fig. 12. — A. oswegoensis M. and G. sp. Upper Silurian, Oswego, 111. Posterior 

 view. 



In all these the radianal is seen in primitive position directly below the right 

 posterior ray. 



Lecanocrinus Hall 



Fig. 13. — L. macropetalus Hall. Upper Silurian, Lockport, N. Y. Posterior 

 view, showing radianal obUquely under right posterior radial. 



Fig. 14. — Ibid. Anterior view of another specimen, to show absence of regular 

 interbrachials. 



Metichthyocrinus n. g. 



Fig. 15. — M. hurlingtonensis Hall. L. Carboniferous, Burlington, Iowa. With- 

 out any radianal. 



Oligocrinus Springer 



Fig. 16. — O. asteriaeformis Hall. L. Carboniferous, Burlington, Iowa. Anterior 

 view of one of the type specimens; to show the mode of arm-branching. 



Parichthyocrinus Springer. 

 Fig. 17. — P. nobilis W. and Sp. L. Carboniferous, Burlington, Iowa. Pos- 

 terior view; anals in tubelike series. 



NiPTEROCRiNUS Wachsmuth 

 Fig. 18. — N. wachsmiithi M. and W. L. Carboniferous, Burlington, Iowa. 

 Basal view; anal side not distinct; infrabasals probably coalesced. 



Wachmuthicrinus Springer 

 Fig. 19. — W. thiemei Hall. L. Carboniferous, Burlington, Iowa. Basal view; 

 no anal plates, but posterior basal in this specimen the largest. 

 (Figs. 4, 5, 6, 8, 9, and 11 after Liljevall.) 



EXPLANATION OF PLATE VII 

 Calpiocrinus Angehn 



Fig. I. — C. fiinbriatus Ang. Upper Silurian, Gotland, Sweden. Anterior radial 

 view; from original to Angelin, XXIX, 77. 



Fig. 2 — Ibid. Basal view of same specimen; the infrabasals covering the basals 

 ex'cept at the posterior side, but partly removed at two places to show points of other 

 basals. 



Fig. 3. — C. heterodactylus Ang. Upper Silurian, Gotland, Sweden. Basal view 

 of calyx, with column ossicle attached; showing the enormous infrabasals, with pos- 

 terior and two other basals visible as mere points. 



Fig. 4. — C. ovatus Ang. Upper Silurian, Gotland, Sweden. Basal view of 

 calyx, from original to Angelin, XVI, 17-19; all basals except the posterior com- 

 pletely hidden by the infrabasals. 



