INDIANA PALAEONTOLOGY. 200. 



in diameter. Number of lamellai seventy in the circumference of a calix twen- 

 ty-five millimeters in diameter, slightly unequal in size at the margin, alterna- 

 ting below; the short ones descends to the bottom of the cup and gradually dis- 

 appear, the longer ones continue to the margin of the horseshoe-shaped 

 area in the center of the calix and abruptly end. Exterior rugged with sharp 

 constrictions and strong rounded annular lines of growth, denticulations mod- 

 erately coarse, four in the space of two millimeters. 



Found in the Upper Devonian, (Hamilton g^roup) at Speed's cement quarry 

 and in the strippings above the cement beds throughout Clark county, Ind. 

 Now in the collection of the author. 



HELIOPHYLLUM INFLEXUM, N. Sp. 



Plate 59. Figs. 1, 2, 3, 4. 



Corallum simple, turbinate, straight or regularly curved. Acute, or some- 

 times there is a broad scar at the base of attachment. Height varying in dif- 

 ferent examples, from fifteen to sixty millimeters or more in some corallums. 

 Calix oblique, circular or broadly oval, from twenty to thirty millimeters in di- 

 ameter. Depth ten to fifteen millimeters. The bottom of the calix is oblique, 

 more strongly pronounced in some cups than in others. Number of lamellae 

 ninety-two in the circumference of a cup twenty-five millimeters in diameter, 

 thin and somewhat sharp, and alternating in size at the margin, getting thin- 

 ner and alternating in length, gradually sloping to the bottom of the calix 

 where the short ones terminate; the longer ones continue to the bottom of the 

 cflklix, and from five to eight of the principal ones extend across the bottom of 

 the cup connecting with the opposite ones, generally at right angles, or slight- 

 ly oblique to the principal fossette. The intermediate lamella? converge to 

 those that extend across the bottom of the cup. There are two lateral fossettes 

 situated on either side of the principal one; the position of these is variable, 

 and occasionally there is one that is poorly defined. The exterior is very ru- 

 gose, with numerous sharp constrictions giving to the corallum the appearance 

 of a series of invaginated calices. The denticulation are absent in worn or 

 weathered specimens, but they are well defined in well preserved examples. 



This species is common in the Middle Devonian, (upper Helderberg group) 

 Falls of the Ohio. Now in the collection of the author. 



HELIOPHYLLUM O B LIQ U UM, N. Sp. 



Plate 59. Figs. 5, 6, 7. 

 Corallum simple, turbinate, or elongate turbinate, straight or regularly 



