1878.] 52d [Cope. 



which are widely separated on the anterior part of the muzzle, and which 

 converge in front of the orbits, which they barely reach. Another groove 

 occupies the inferior margin of the dentary bone. There is a deep auricu- 

 lar fossa beneath the epiotic and posterior part of the pterotic bones. There 

 is but one series of teeth on each maxillary and dentary bone exposed by 

 the present condition of the specimen. The teeth are subequal, gradually 

 increasing in size anteriorly where their long diameters are transverse to 

 the axis of the dentary bone. The surface of the cranial bones is not 

 strongly sculptured. Posteriorly it is rather closely, and anteriorly it is 

 sparsely, punctate. The sculpture of the lower jaw is similar, except that 

 it is smoother posteriorly. 



As this species has been already described, further detail is not now 

 given. The present specimens show that the species was founded on a 

 caudal intercentrum, and that the C. discopliorus* was founded on dorsal 

 intercentra. They also show that my original reference of loose phalanges 

 to this genus was correct. 



Zatrachys serratus. Gen. et sp. nov. 

 Char. Gen. The existence of this genus is demonstrated by various 

 fragments, the most characteristic of which is a portion of a maxillary 

 bone. This probably belonged to a species of the order Stegocephali, but 

 whether to the Ganocephalons or Labyrinthodont division is uncertain, 

 though the evidence is in favor of the former. The teeth are in a single 

 series, and their bases are anchylosed to the bottom of a shallow groove. 

 The external boundary of this groove is more prominent than the internal, 

 so that the attachment of the teeth is shortly pleurodont. The teeth have 

 conic crowns, and have basal grooves indicating the dentinal inflexions 

 common to this group. The maxillary and other bones are characterized 

 by their strong sculpture, in the former the ridges being developed into 

 prominent tubercles in various places. 



Char- Specif. The horizontal expansion of the maxillary bone is a char- 

 acter of this species, so that its plane forms an obtuse angle with that of 

 the long axes of the teeth. It presents no palatal lamina. The teeth are 

 separated by intervals of greater width than the diameter of the base. 

 The border of the bone above the teeth is thickened, and the ridges are de- 

 veloped into numerous tubercles. These project externally so as to form 

 a prominent serrate margin entirely overhanging the external alveolar 

 border. The ridges diverge inwards in a radiating manner. The surface is 

 otherwise irregnlar from the presence of a deep fossa on the outer side 

 within the inner alveolar border. 



Measurements. M. 



Length of fragment 018 



Width " " 018 



" " alveolar groove 002 



Length of prominences beyond alveolar border 003 



Diameter of a tooth basis ". . . .001 



Three teeth in 005 



* Proceed. Amer. Philos. Soc, 1878, p. 186. 



