A NEW FOSSIL FISH FROM DURA DEN 233 



Dr. Traquair, the skulls are similar in form, although differing 

 in minor details, and have a general resemblance to the 

 South African Dicynodon and Oudenodon, some of them 

 having small tusks in the maxillary bones. With most of 

 these skulls parts of the skeleton have been found. Two or 

 three show the position of the vertebral column and ribs, but 

 up to the present no definite centra have been traced ; besides 

 this there is evidence of scapula, clavicle, humerus, radius, 

 and ulna, the humerus having the characteristic anomodont 

 expansion of the two extremities. In two specimens the ilia 

 are preserved. These forms appear to be distinct from Dicyn- 

 odon, and probably represent at least two or three species. 



Another skull presents most of the characters of Ptycho- 

 gnathus, but has a short muzzle and no teeth. The last, and 

 by far the most remarkable skull of this series, is about six 

 inches in length, and has the outer surface completely covered 

 in by bony plates, the nostrils, eyes, and pineal fossa being 

 the only apertures. The chief feature of this skull is the 

 extreme development of horns upon the face and cheeks, 

 there being about thirty of these formidable defences, varying 

 from a fourth of an inch to nearly three inches in length, 

 besides some smaller bosses. The dentition is pleurodont, 

 and resembles very closely that of the living Iguana ; the 

 palate is lacertilian, but with the pterygoids united in front 

 of the pterygoid vacuity. This skull reminds one very 

 strongly of the living MolocJi and Phrynosoma, but it 

 probably finds its nearest ally in the Pareiasaurus from the 

 South African Karoo Bed. 



A NEW FOSSIL FISH FROM DURA DEN. 



By R. H. TRAQUAIR, M.D., F.R.S. 



Keeper of the Natural History Collections in the Museum of Science 



and Art, Edinburgh. 



SOME years ago, while looking over the magnificent collection 

 of Dura Den fishes in the Museum at St. Andrews, Professor 

 Heddle drew my attention to a specimen which, though 

 bearing some resemblance in form to a Glyptolceinus^ seemed 



