KONGL. av. VET. AKADEMIENS HANDLINGAli. BAND 32. N:0 I. 



129 



Plate VIII. 



Plasmopora scita Edw. & H. p. 81. 



Fig. 1, 2. Aspects of diffcrent calicles to be compaved 

 with figs. 6 & 16 on plate Til sliowiug 

 tlie sradual transition of calicle tig. 6 



through 1 aiid 2 to fig. 16, pl. VII, magni- 

 fied. «/i- 

 Fig. 3. Calicle of a variety of Pl. scita. ''/i. 



It is to be obsevved that tlie Communications with tlie coenenchyma in the margin of the calicle exist 

 only on tbe surface of the coral. 



Propora tubulata Lonsdale p. 89. 



Fig. 4 — 7. Surface and sectious of a specimen from 

 Dudley, England. Fig. 4 typical form with 

 calicles resembling those in Milne Edward's 

 figures, "/i. Figs. 5 — 7 magnified, 'Vi. Fig. 

 7 basal part of fig. 6 showing epithecal 

 geramation. 



■» 8. Surface of a specimen from Gotland, Wisby; 

 stratum cl, the costal radii replaced by 

 convex laminae of the same kind which 

 constitute the vesicular tissue of the interiör; 

 they are covered with minute warts, or aculse 

 probably of the same sort seen iu the in- 

 teriör on the top of the convex lamina?. ^'ji. 



» 9, 10. Sections of the same specimen. In f. 9 

 between the calicles the convex laminffi 

 sectioued. 



» 11. Surface showing a variety approaching to that 

 in fig. 8 the concave laminse nearly all effaced 

 and the surface of the coenenchyma granu- 

 lated. From Wisby d. ^/i. 



Fig. 12, 13. Sections of the same, the longitudinal one 

 showing great sirailarity with that of Plasm. 

 scita. Vi- 

 14, 15. Sections of another specimen from Wisby. 



Vi. 



16, 17. Sections of a specimen from Oesel, Undwa, 

 belonging to the Geological Survey of 

 Sweden. '^/i. 

 .■ 18, 19. Sections of a specimen from Borkholm, Est- 

 land, Lower Silurian, stratum F^. Older 

 variety with distantiated calicles and more 

 compact vecicular tissue. Vi- 

 Surface, nat. size, of same specimen as in iigs. 



16, 17. 

 Surface, nat. size, of specimen 18, 19. 

 22. Ditto of specimen from the Arachnophylluni 

 stratum a of Wisby same variety as in figs. 

 18, 19. 



20 



21 



Propora euryacantha n. p. 92. 

 Fig. 23. Calicle showing the tlat triangulär septal spines, specimen from Fårö, Gotland, "/i- 



Propora tubulata, var. p. 91. 



Fig. 24, 25. Sections of specimen, called Lyellia americana . Edw. & H., from Point Detour, Michigan, to be com- 

 pared with fig. 10 & 15. 



Propora euryacantha n. 

 Fig. 26, 27. Sections of specimen from Färö, of another specimen than in tig. 23. Fig. 26 near the surface. 



