74 NEW PALEOZOIC VERTEBKATA. [Feb. 5, 



half as wide or more, than the width of the tract of coarse ridges. 



In this character and in the finer and less inosculating coarse ridges 



it differs from the H. inflexiis. 



Measurements. mm. 



Vertical diameter of scale 46 



Longitudinal diameter of distal ridged area 22 



'' " *' proximal tubercular area. . . 11 



Five coarse ridges in 5 



Five rows of tubercles at base of tract in 4 



Seven tubercles in. 5 



From the collection of Mr. R. D. Lacoe. 



HoLOPTYCHius LATUS, sp. nov. PL II, Fig. 2. 



Represented by the two scales from the greenish clay rock of 

 Factory ville, Pa., said to be of Catskill age. The species prob- 

 ably belongs to the section Glyptolepis Ag., and is the first one 

 found in this country. The distal part of the scale presents eight 

 coarse ridges, which are separated by grooves narrower than them- 

 selves, and which do not inosculate. One of them appears to be 

 interrupted. The central part of the scale is smooth, being only 

 interrupted by the tube of the lateral line. The circumference 

 from one side of the tract of coarse ridges to the other presents 

 a wide band, which is primarily sculptured by fine ridges which 

 radiate to the margin, and which are cut by concentric ridges of 

 different degrees of coarseness, but which are coarser than the radi- 

 ating lines. These characters are more exactly defined by the fol- 

 lowing : 



Measurements. mm. 



Vertical diameter of scale 20 



Transverse diameter of scale 17 



Three distal coarse ridges 3 



Seven proximal concentric ridges 3 



Width of border of concentric ridges 6 



Eight radiating ridges in i 



The scales of this species differ from all those hitherto described 

 in the coarseness and small number of the distal ridges. Their par- 

 allel course distinguishes them from some species, and their failure 

 to reach the center of the scale separates them from others. In size 



