CORAtLINE LIMESTONE. 



323 



680. 1. COLUMN ARIA INEQUALIS (n. sp.). 



PL. LXXII. Fig. 3 a, b, and 4 a, b, c. 



Coral in hemispheric or irregular masses composed of angular (5 or 6-sidecl) tubes, which 

 open on the surface in a eel) more or less deep ; rays twenty to thirty ; lamellae apparently 

 equal, often undulating ; interspaces showing numerous connecting plates; lamelte uniting in 

 the centre without any apparent axis ; full grown terminal cups often very deep, with num^erous 

 young ones interpolated ; structure prismatic, walls of cells separable, outer surface deeply 

 striated; vertical section showing an exterior cellular structure, the interior showing lamellffi 

 diverging upwards and outwards. 



This coral presents so many characters in common with the specimens of Columxaria 

 figured and described by Goldfuss and Lonsd.\le, that I can not hesitate to refer it to this 

 genus, though not possessing fully the characters given by Prof. Dana. In the specimens 

 examined the masses have not attained any large size, though one or two of them may have 

 been five or six inches in diameter. The cells opening upon the surface are very unequal in 

 size, a large number being those of small or young polyps which appear to be interposed be- 

 tween the walLs of contiguous cells. The full grown cells are distinctly angular, of five, six or 

 seven unequal sides ; while the young cells are often triangular, and sometimes distinctly oval, 

 the walls being usually more or less curved. Solid specimens sometimes separate in prisms, 

 the exterior walls of which are deeply striated or fluted, arising from the arched union of con- 

 tiguous lamellae ; thus leaving the more prominent parts of the surface representing the spaces 

 between the lamellce, while the narrow indentation represents the place of the lamella. When 

 the exterior surface is weathered, it presents a cellular structure, from the intersection of the 

 lamellcB and connecting dissepiments, as in fig. 4 b. When the columns are still farther 

 weathered, this external cellular portion is sometimes worn away, and the interior portion 

 alone remains, as in fig. 4 c, the natural position of which is reversed. 



Fig. 3 a. A part of the surface of a small irregular mass, showing fewer j'oung cells than is usual. 

 Fig. 3 b. Several of the same enlarged. 



The elevated point in the centre gives a wrong impression as to the character of 



the cup. Such elevated points, where they do exist, are apparently accidental or 



unnatural. The transverse dissepiments connecting the lamellte are not well shown 



in these figures. 

 Fig. 4 a. A portion of a specimen, showing the prismatic structure of the coral. 

 Fig. 4 i. A weathered portion enlarged, showing the cellular exterior structure. 

 Fig. 4 c. A reversed figure, the lower extremities of several columns enlarged, showing the 



mode of weathering, and the structure after the removal of the exterior cellular area. 



Position and locality. In the Coralline limestone at Schoharie. 



(Collection of Juhn Gebhard junior.) 

 [PAL.fiONTOLOGV — VoL. II.] 41 



