PALiEOZOIC CORALS AND FORAMINIFERA. 71 



space between this inner area and the outer wall is regularly 

 radiated with from sixty-three to sixty-nine equal, thin, rather 

 distant lamellse connected by numerous delicate, transverse, 

 vesicular plates ; terminal cup deep, lined by the vertical la- 

 mellse, and having a large oval prominent boss in the centre 

 traversed by a sharp mesial crest ; about one-half or one-third 

 of the radiating lamellse ascend the central boss, always in a 

 direct line, those at the sides of the mesial crest being at right 

 angles to it, the others joining at a more acute angle as they 

 approach the extremity, and opposite one end of the crest we 

 generally observe one or two of the radiating lamellse shorter 

 than the rest, producing a sort of siphon-like irregularity such 

 as we see in Caninia : vertical section indistinctly triareal ; 

 outer area defined, about one- sixth of the width on each side, 

 composed of small, much-curved, vesicular plates, forming 

 small semicircular cells arranged in very oblique rows upwards 

 and outwards, about seven in a row ; inner zone about equal- 

 ling the outer one in width, passing gradually into the central 

 structure, formed of slightly larger and less curved vesicular 

 plates than the outer zone, and having a nearly horizontal di- 

 rection ; central area composed of large, thin, close, little- 

 curved, vesicular plates, forming a strongly arched series of 

 narrow, elongate cells, the convexity of the arch upwards, con- 

 forming to the shape of the central boss in the cup ; if the ver- 

 tical section be at right angles to the medial fissure or crest of 

 the central boss, there is a line visible down the middle of the 

 section. 



This coral is interesting to the physiologist from the combi- 

 nation of the bipartite or symmetrical with the radiated type of 

 structure, as in some Fungice, &c. It nearly equals the Caninia 

 gigantea (Mich.) in size and cylindrical form, but is easily distin- 

 guished by the strong longitudinal strise of the surface, the want 

 of transverse septa in the central area, &c. 



Rather common in the carboniferous limestone of Derbyshire. 



{Col. University of Cambridge.) 



Clisiophyllum prolapsum (M^Coy). 



Sp. Char. Elongate- conic, much curved and twisted on its axis, 

 terminal cell oblique, deep, with steep sides, a narrow flattened 

 or concave space at bottom, from which protrudes the central 

 boss, which is about one-third the diameter of the cup, nearly 

 as high as wide, cylindrical, obtusely rounded above, and with 

 a deep umbilical cavity in the middle (in partially decomposed 

 or weathered specimens a rough vertical fracture frequently 

 shows the central area as a thick, smooth, persistent tube) ; 



