GLYPTOPOMUS MINOR. 



5 



The general character of the sculpture is the same on the dorsal 

 as on the ventral scales. On the right side of the body some few 

 of the scales in the position of the lateral line exhibit a grooved 

 character, which is somewhat more prominent in the figure than it 

 appears to my eye to be in nature. 



The impression of the anterior dorsal fin {D) commences at 

 seven inches and three-tenths from the anterior extremity of the 

 muzzle ; that of the second dorsal (D^) at about nine inches and a 

 half from the same point. 



The fin rays of the ventrals (V) are visible on one side in 

 the dorsal impression (fig. 1), and, on both vsides, in the ventral cast, 

 just in front of the second dorsal. They seem to have been 

 broad, but far shorter than the pectorals, and the impressions 

 are so indistinct that I cannot say whether they are lobate or 

 not. 



The pectoral fins (P, P,) are exquisitely displayed; each has- 

 a broad scaly lobe, subacute at the extremity, and more than an 

 inch long, by half an inch wide. The scales exhibit the same 

 sculpture as those on the body, but are much smaller, and 

 diminish in size towards the apex of the lobe. The many-jointed 

 fin rays are attached all round the margins of the lobe, and 

 become longer towards its apex, wliere they form fully half of the 

 length of the fin. 



I see no trace of the anal fin in either slab. The impression 

 of the well-defined upper lobe of the caudal ( C) commences at 

 eleven inches and a quarter from the anterior extremity of the 

 muzzle. The lower lobe is not well shown in either slab ; but 

 I suspect from the size of the upper, that the tail is diphycercal. 



The only tooth of Glyptopomus I have seen, fig. 4, is stout, 

 conical, slightly curved, and deeply grooved longitudinally. 



The jugular plates and the mandibles have a coarsely pitted 

 and ridged sculpture (PI. I., fig. 3). 



These facts leave no doubt as to the })osition of Glyptopomus 

 in the Glyptodipterine family of the suborder Crossopterygidcs 

 among the Ganoidei. 



Description of Plate I. 



Fig. I . The cast of a specimen of Glyptopomus minor. In Dr. Taylor's Collection. 

 Nat. size. 



Fig. 2. The skull of a larger Glyptopomxis viewed from above. It is described in 

 Decade X. " Introductory Essay," p. 4. In the British Museum. Two- 

 thirds of the size of nature. 



Fig. 3. A fragment showing the sculpture of the jugular plates (G) and the man- 

 dible {Mn). In the Museum of Practical Geology. Nat. size. 



Fig. 6. A slab with well preserved scales and a tooth of Glyptopomus. Nat. size. 



The tooth and one of the scales are represented separately and magnijSed. 



