NEW FACTS CONCERNING BOTHRIOLEPIS. 



WILLIAM PATTEN. 



In the following paper, I shall present a preliminary account 

 of my observations on a large collection of Bothriolepis recently 

 obtained in New Brunswick. A more complete and fully illus- 

 trated account will be presented later. 



This new material shows structural features heretofore un- 

 known, and much that one could hardly hope to see preserved in 

 any fossils, especially in ones so old as these. 



The trunk, Fig. i, was very slender and covered with a soft 

 skin devoid of scales or of any other markings except those men- 

 tioned below. In spite of its delicate structure it is often only 

 moderately compressed, or distorted. In the region of the pos- 

 terior dorsal, it may present a somewhat triangular cross section, 

 resembling that of CcpJialaspis in a corresponding region, but 

 without any traces of a lateral fold or of fringing processes. 



A few small irregular plates, with the typical sculpture of the 

 buckler, are imbedded in the skin along the dorsal surface, im- 

 mediately in front of the anterior dorsal, and numerous minute 

 ones are scattered irregularly over the flanks in the same region. 



One specimen shows indications of a lateral groove, and, dorsal 

 to it, a few oblong folds suggestive of segmentation. 



The anterior dorsal fin is low and elongated, the posterior one 

 very high and rounded. Both fins are often preserved with won- 

 derful clearness, but show no other detail than a faint striation 

 probably due to the presence of delicate subdermal rays. 



The elongated tail, with its axis slightly curved, terminates in 

 a narrow band. The dorsal margin consists of a delicate mem- 

 brane, strengthened by a row of curved rods lying close together 

 and arranged with great regularity. The basal ends of the rods 

 are swollen, and one is turned a little to the left, and the adjacent 

 one, to the right, of the median line. The rods extend on to the 

 ventral margin of the terminal band, into the ventral lobe. The 

 latter is faintly striated like the dorsal fins. Its anterior ventral 

 margin appears to divide, as though it were continued forward 



