INDIANA PALEONTOLOGY. J80. 



ulae and gradually disappear, the longer ones continue on the tabulae to the cen- 

 ter of the calix ; for the last three or four millimeters they become flexuous, 

 4ind in some cups they fasciculate, and sometimes the ends of the lamellse is 

 broken up and gives to the bottom of the cup a rugose appearance. Fossette 

 consists of a broad, deep depression at the margin of the tabulae, but gradu- 

 ally disappears before reaching the margin of the calix, position on the long- 

 est side of the curviture of the coral. 



Found in the Upper Devonian (Hamilton group) near Charlestown, and in 

 the strippings above the cement rock at the different cement quarries through- 

 out Clark county, Indiana. Now in the collection of the author. 



HELIOPHYLLUM PARVULUM. N. Sp. 



Plate 53. Figs. 7, 8, 9. 



Corallum simple, turbinate, straight or regularly curved, with a broad scar 

 at the point of attachment. Height varying in different examples from fifteen 

 to thirty millimeters. Exterior frequently very rugged with rough irregular 

 annulations, and deep constrictions, and rough wrinkles, caused by intermit- 

 tent growth. Calix in some examples badly constricted, in some others broad- 

 ly bell-shaped. Diameter from twenty to thirty millimeters. Depth fifteen 

 millimeters, an oblique convex space in the bottom of the calix occupied by the 

 tabulae, from ten to fifteen millimeters in diameter. Number of lamellae, eighty 

 in the circumference of a calix, twenty-five millimeters in diameter, sharp and 

 unequal in size at the margin, alternating below, gradually, or in some exam- 

 ples rapidly sloping to the bottom of the calix, where the short ones gradually 

 disappear, the longer ones continue to within three or four millimeters of the 

 center, and abruptly ends, leaving a smooth concave space in the bottom of the 

 calix, from six to eight millimeters in diameter. Fossette consists of a slight 

 depression at the margin of the tabulae, but gradually disappears before reach- 

 ing the anterior margin. Denticulations moderately fine, twelve in the space 

 of eight millimeters. 



Found in the Upper Devonian (Hamilton group) at Charlestown, and at 

 the different cement quarries, throughout Clark county, Indiana. Now in the 

 collection of the author. 



ARACHNOCRINUS EXTENSUS, W. <k Sp., Rowley. 

 Plate 54. Fig. 1. 



The specimen we have figured, although somewhat weathered, preserves 

 the arms to near their distal ends. The whole lies upon a slab with the calyx 

 imbedded in the matrix. 



