90 PALEOZOIC CORALS AND FORAMINIFERA. 



downwards and outwards from tlie axis, and an outer zone of 

 small vesicular plates inclined in an opposite direction or up- 

 wards and outwards : horizontal section, axis thin, half a line 

 wide, surrounded by about forty- three thin, radiating lamellae 

 from the walls, half of which only reach half way ; numerous 

 small, thin, transverse connecting plates between the lamellae 

 in the outer zone. 



The bipartite mode of division of the column is frequently 

 and easily observed in this species, which commonly forms large 

 masses. It gi'eatly resembles externally the Stylastroia hasalti- 

 forrnis, but is easily distinguished by the small, but distinct, cen- 

 tral axis visible in the transverse fracture, and further by the dif- 

 ferent disposition of the lamellae of the inner zone. The small 

 size of the tubes and less number of lamellae distinguish it from 

 the Stylaxis major. 



This is probably the Lithostrotion striatum of Fleming (Brit. 

 Anim.), as he particularly says, '^ the rays of the star unite with 

 a small solid central axis." I think however with Mr. Lonsdale, 

 that he is wrong in his references. I have great pleasure in de- 

 dicating it to so admirable a naturalist, the extraordinary merit 

 of whose writings on the British marine animals is well known 

 to all who engage in the same laborious and difficult study. 



Common in the carboniferous limestone of Derbyshire. 



{Col. University of Cambridge.) 



Columnaria (Gold, as here redefined). 



Gen. Char. Corallum of aggregate, subparallel branches, either 

 round and concentrically wrinkled, or more usually by mutual 

 pressure becoming polygonal and longitudinally sulcated, but 

 always easily separable; internal structure as in Amplexus, 

 having many transverse simple diaphragms, and the walls lon- 

 gitudinally sulcated by marginal rudimentary lamellae, which 

 crenulate the edges of the transverse plates. Increase by fis- 

 sure of the parent tube or cell, as in Stylastraa (Lonsd.). Type 

 of the genus Columnaria sulcata (Gold.). 



This genus has been erroneously described by Goldfuss in the 

 first instance, and has been misunderstood by nearly every sub- 

 sequent author — all describing radiating lamellae from the walls 

 to the centre, and stating that there are no transverse plates ; I 

 was rather surprised therefore to find the characters I have given 

 above, in authentic specimens from the Eifel of the C. sulcata 

 (Gold.) ; they also exist in the C. irregularis (Miinst.), C. senilis 

 (Koninck), and the following. I deny the existence in those species 

 of radiating lamellae near the centre, and find the transverse dia~ 



I 



