INDIANA PALEONTOLOGY. I85. 



HELIOPHYLLUM SULCATUM. 



Plate 55. Figs. 1, 2, 3, 4, 5, 6. 



Caninia Sulcata D'orbigny, .Prodr. d, Palaeontology, T, 1, P. 105, 1850. 



Aulacophyllum Sulcatum, E. & H. Polypiers Fossiles, des Terr. Palsoz., page 355, plate 6, 

 figure 2, 1851. 



Aulaeophyllnm Sulcatum, Hall. Indiana Geological Survey, Page, 279, Plate 17, Figures 7 

 to 10, 1882. 



Corallum simple, turbinate, or elongate turbinate, acute at the point of at- 

 tachment. Gradually enlarging in diameter to the calyx. Height of the longest 

 example seven inches. Calix oblique, three inches in diameter. Depth forty- 

 five millimeters. Number of lamellae, one hundred and seventy, very fine and 

 equal in size at the margin, alternating below, gradually sloping to the bottom 

 of the calix where the short ones terminate, the longer ones continue, coalescing 

 and fasciculating and abruptly end before reaching the center of the calix, 

 leaving a smooth depressed oblique space in the bottom of the cup, ten millime- 

 ters wide and twenty-five millimeters long. Denticulations are very fine, and 

 can only be seen in places where the lamellae has been protected from weather- 

 ing. Fossette conspicuous, consists of a deep depression at the margin of the 

 smooth space in the bottom of the calix, and continues as a deep broad groove 

 to the anterior margin of the cup, when the long smooth space in the bottom of 

 the calix is absent, by decay or otherwise it makes the fossette appear like one 

 long deep groove, extending almost the entire diameter of the corallum. 



Found in the Middle Devonian(Upper Helderberg group) at the Falls of the 

 Ohio. All the specimens illustrated are in my collection. 



HELIOPHYLLUM GRADATUM, N. Sp. 



Plate 56. Fig. 1. 



Corallum composite, rapidly increasing by calicular gemmation. Stems 

 growing loose, never in contact for any distance. Corallites are deeply con- 

 stricted, somewhat regularly, giving them the appearance of rough circular 

 swellings, or strong rounded annulations. Each cup puts forth four or five 

 buds, they again bud and a repetition of gemmation is often repeated. Buds 

 at the margin of the parent cup have a diameter of five millimeters, gradually 

 enlarging to the calix. Height from one cup to another varies in the 

 same corallum from twenty to forty millimeters. Diameter of the calix 

 ten to fifteen millimeters. Depth five to eight millimeters. A smooth 

 convex space in the bottom of the calix, occupied by the tabula^, four 

 millimeters in diameter. Number of lamellae fifty in the circumference of a ca- 

 lix ten millimeters in diameter, equal in size at the margin, alternating below. 



