l8 SMITHSONIAN INSTITUTION 



PLATE VI 



(All figures natural size except where otherwise stated) page 



Figs. I-I2. Homalocrinus parabasalis Angelin 154 



Figs. 10, b. The type, from 1. ant. radius and anal side; original of Angelin, pi. 16, figs. 29, 30, show- 

 ing the two main divisions of the ray with ramules to the inside; RA barely visible 

 between r. post. R. and IBr. X 2. Riks Museum. Gotland (/). 



ic. Basal view of same; BB covered by IBB, except small angular points. X 2. 



id. R. post, view of base, showing small RA more distinctly. X 2. 



20, b, c. Posterior, basal and distal views of young specimen with RA and all BB covered by 

 growth of IBB. X 2. Riks Museum. Wisby (/). 



3a. Specimen from Dudley, England, somewhat flattened, with RA under r. post. R; posterior 

 view. X 2. Author's collection. 



36. Basal view of same, showing RA distinctly and BB well exposed. X 2. 



4. Another specimen from Dudley, with RA prominently visible above IBB. X 2. Author's 



collection. 



5. Similar specimen with RA and BB prominent; posterior view. Natural size. British 



Museum, E. 7426. Dudley. 



6. 7, 8. L. post., and post, views of specimens with only points of BB, and no RA, visible above 



IBB. Natural size. British Museum, E. 1422, 57258, 57476. Dudley. 



9. Nearly complete flattened specimen, r. post, view ; RA not visible and only small points 



of BB ; showing also character of stem with strong, alternating joints diminishing 

 from the calyx. X 2. Author's collection. Dudley. 



10. Anterior view of similar specimen with stem, showing well the heterotomy of the rays. 



Natural size. Author's collection. Dudley. 



11. Flattened specimen in same condition. Natural size. Same collection and locality. 



12. Sketch constructed from the above specimens to show how RA may be concealed by the 



growth of IBB, while leaving points of BB visible — e. g. in cases where IBB reach the 

 dotted line b — b, as in figs. 6, 7, 9; if they only reach a — a, BB will be seen connecting 

 and RA well exposed, as in figs. 30, 5 ; while if they grow higher than b — b, neither 

 RA nor BB can be seen, as in figs. 2a, b, or only post. B, as in fig. 13&. 

 Wenlock Gr. ; Silurian. Gotland and England. 



Figs. 13-15. Homalocrinus liljevalli n. sp ISS 



Fig. 13a. The principal type, r. ant. radial view; all BB, except posterior, covered by growth of 

 IBB; lower ramule enlarged and bearing secondary ramules; 2 rows of iBr in upper 

 part of interradius. X 2. Author's collection. Wisby (d). 



136. Basal view of same. X 2. 



140. R. ant. view of smaller specimen, with more of BB exposed ; IBB broken off. Author's 

 collection. X 2. Wisby (d). 



14b. Basal view of same, showing space formerly occupied by inner part of IBB, within ring 

 of BB ; RA concealed by IBB when in place. X 2. 



150. Specimen with calyx" broken away just below the tegmen; lateral view of part of rays: 

 o =: outer ramus, i = inner. X f- Riks Museum. Wisby (d). 



TS&. View of same from below, showing under side of finely plated tegmen with 5 oral plates 

 in the middle, and ambulacra passing between them to the arms. X 2. 

 Wenlock Gr. ; Silurian. Gotland, Sweden. 



