CATALOG OF THE FOSSIL FISHES IN THE CARNEGIE MUSEUM. 395 



"Portions of the fin-membrane or shagreen-covering of the pectoral pair, as 

 well as the greater part of the pelvic, anal, and caudal fins are preserved. The 

 anal is nearly opposite the posterior dorsal, and except for being more sharply 

 pointed, resembles it in form and proportions. The pelvic pair is decidedly acumi- 

 nate, and placed midway between the anal and pectoral pair. The pelvics slightly 

 exceed the second dorsal in size, which latter is somewhat higher and longer than 

 the first dorsal; and the depth [width] of the pectorals is about one third greater 

 than that of the pelvic pair. Nearly the entire front margin of the right pectoral 

 fin is preserved, but the distal portion of the left pectoral is either concealed or 

 broken away. The same is true of the terminal part of both lobes of the caudal."^ 

 The general outline of body and position of all the fins is shown in Plate LVII, 

 fig. 1. The shaded area immediately behind the head and thoracic region indi- 

 cates a fracture in the containing rock. 



The configuration of the head is well shown by a continuous mass of calcified 

 cartilage and closely crowded shagreen granules preserved in natural position. 

 Teeth are not visible, the head being exposed from the dorsal aspect without indi- 

 cations of mouth-parts. Two forwardly placed openings are probably to be 

 interpreted as nasal and orbital respectively. 



Fine shagreen granules bearing each a single acuminate recurved spine occur 

 in regular series everywhere over the surface of the body, and cover the fin-membranes 

 as well. Just above the vertebral column and evidently indicating the median 



c s b 



Fig. 1. Surface view of the dermal denticles of Scyllium sp. (From Bridge after Klaatsch, 

 Cambridge Natural History, Vol. on Fishes, p. 184, fig. 99.) b, basal plate; c, canal which perforates 

 basal plate and becomes the axial pulp-cavity of the spine; /.6., intersecting fibrous bands of the dermis; 

 s, spine; in the spine of one scale the dentinal tubules are shown. The smaller denticles are those most 

 recently formed. 



line of the back is a longitudinal series of spinules corresponding to ridge-scales, 

 which extends from the anterior dorsal fin caudad nearly to the base of the upper 

 lobe of the tail. 



6 Eastman, C. R., I. c, pp. 401-402. 



