20 



PALEONTOLOGY. 



not always solitary, or merely in groups; some species of 

 Cyatlwpliyllum constantly form compound masses, with cups 

 rendered polygonal by contact, like G. regium of the Bristol 

 limestone. The allied genus Acervularia (fig. 4, 8) resembles 

 an Astrcea, and exhibits, in a remarkable manner, the multi- 

 plication of its corallites by calicular gemmation. The genus 



Fig. 4. 

 Palaeozoic Corals (Anthozoa). 



i. Amplexus Sowerbyi, Ph. ; Carboniferous, Ireland. 



2. Cyathophyllum turbinatum, Lin. ; U. Silurian, Wenlock. 



3. Cyathophyllum subturbinatum (section) ; U. Silurian, Wenlock. 



4. Cystiphyllum Siluriense, Lorisd. ; U. Silurian, Wenlock. 



5. Zaphrentis Phillipsi, M. Edw. ; Carboniferous, Somerset. 



6. Lithodendron irregulare, Ph. ; Carboniferous, Europe. 



7. Lithostrotion striatum, Flem. ; Carboniferous, Europe. 



8. Acervularia luxurians, Eich. ; U. Silurian, Europe. 



9. Heliolites interstincta, Wahl. ; U. Silurian, Europe. 



10. Syringopora ramulosa, Goldf. ; Carboniferous, Europe. 



11. Halysites catenulatus, L. ; Silurian, Northern Regions. 



12. Favosites Gothlandica, Lam.: Silurian, North. 



Lithostrotion (fig. 4, 7) of the carboniferous limestone is also 

 compact and astraeiform, but the new corallites are produced 

 by lateral gemmation. Corals, with the same structure, but 

 not compact, are known by the name Lithodendron (fig. 4, 6). 



