PLATE III. 



UlNTACKINUS SOCIALIS. A SERIES SHOWING VARIATIONS IN FoRM, SiZE, AND 



OTHER Characters. 



Fig. 1. Specimen, with three individuals, showing dicyclic and monocyclic forms of base, 

 and maximum and small size, lying together in close contact on the slab ; the 

 black membrane lining the calyx is also shown at the edge of the broken plates. 



Specimen No. IX a, b, c. 



" 2. Dicyclic specimen of large size, with the interbrachial areas convex and protu- 

 berant ; one ray is irregular in having 4 primibrachs. No. 45. 

 " 3. Small specimen from Loc. 2 ; monocyclic ; with 3 and 5 plates in iBr areas. 



No. LVw. 

 " 4. Similar specimen ; dicyclic; with 3 and 4 plates in iBr areas. No. LVIII b. 



" 5. One of the smallest specimens ; monocyclic ; with 4 plates in iBr area, and either 



two or no fixed pinnules. No. LV ;. 



" 6. Specimen of medium size ; monocyclic ; with 5 plates in each iBr area visible. 



No. 242. 



" 7. Uintacrinus westfalicus Schlueter. Figure of the type specimen for comparison. 

 (After Schlueter.) 

 (All figures natural size. Figs. 1-5 by Chapman; Fig. 6 by Mrs. Eicker.) 



