chief Generic Types of PalcBOzoic Corals. 461 



EXPLANATION OF THE PLATES. 



(Unless otherwise stated, all the figures are of the natural size.) 

 Plate XXL 



Fiy. 1. Clisiophylluni Keyserlingi, M'Coy (?), transverse section of an 

 extremely large example. Lower Carboniferous, Auchenskeoch, 

 Dairy, A}Tshire. 



Fig. 2. Transverse section of a smaller example of the same species ; 

 2 A, longitudinal section of the same, showing the columellarian 

 line and the convex elevated and vesicular tabulae of the central 

 area. Lower Carboniferous, Broadstones, Beith, Ayrshire. 



Fig. 3. Clisiophyllmn hipartitum, M'Ooy, transverse section a little 

 below the calice ; .3 a, 3 b, 3 c, transverse sections of the same 

 corallum at different heights, showing the difierent stages of 

 growth. Lower Carboniferous, Broadstones, Ayrshire. 



Fig. 4. Longitudinal section of C. hipartitum, M'Coy, showing the triareal 

 structure : 4 a, transverse section of the same, showing the great 

 disproportion between the number of the primary septa and the 

 number of the vertical lamellae of the central area. Lower Car- 

 boniferous, Broadstones, Ayrshire. 



Fig. 5. Clisiophglhim, sp., transverse section ; 5 a, longitudinal section of 

 the same. Lower Carboniferous. 



Fig. 6. Clisiophyllum, sp., transverse section. Lower Carboniferous, 

 Brockley, Lesmahagow. 



Plate XXn. 



Fig. 1. Clisiophyllum, sp., showing the external aspect and the conical 

 boss in the floor of the calice ; 1 a, transverse section of the 

 same. Lower Carboniferous, Broadstones, Ayrshire. 



Fig. 2. Clisiophyllum, sp., transverse section. Lower Carboniferous, 

 Langside, Beith, Ayrshire. 



Fig. 3. Clisiophyllum coniseptum, Keys., longitudinal section ; 3 a, trans- 

 verse section of the same. Lower Carboniferous, Langside, 

 Beith, AjTshire. 



Plate XXin, 



Fig. 1. Aspidophyllum Koninckianum, Thoms., longitudinal section ; 

 1 A, transverse section of the same. Lower Carboniferous, Third- 

 part, Beith, Ayrshire. 



Fig. 2. Aspidophyllum elegans, Thorns., transverse section ; 2 a, calice of 

 the same, showing the helmet-shaped calicine boss. Lower Car- 

 boniferous, Thirdpart, Beith, Ayrshire. 



Fig. 3. A young example of the preceding species, showing the helmet- 

 shaped boss ; 3 A, transverse section of the same. Lower Car- 

 boniferous, Brockley, Lesmahagow, Lanarkshire. 



Fig. 4. Aspidophyllum, sp., transverse section. Lower Carboniferous, 

 Brockley, Lesmahagow. 



F^g. 5. Aspidophyllum, sp., external aspect, showing the calicine bosa in 

 profile ; •'3 A, transverse section of the same. Lower Carboni- 

 ferous, Brockley, Lesmahagow. 



