1878.] 523 ; {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 epioticand 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. discophorus* 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 irregular from the presence of a deep fossa on the outer side 
within the inner alveolar border. 
Measurements. M. 
Lengthrot fra smient). mv siictie ds staisierinrew 6 pioislore crocatateysyeaie .018 
Width ‘“ SEP | abstr std ceotttens Spek eetiemitassseas 7 OLS 
s¢ a so Al MEGAN STLOOME Wieioxchetore.shet-ieiers's sai . .002 
Length of prominences beyond alveolar border......... 008 
Diameter of a tooth basis......... 6 O.d oC GC On CeCe OEE EAL. 
PRINS SME ELI Mii jo ic ned crusts inde oie artieurbderenolexed ge & miaturalslsbssere 5} 4s OE 
* Proceed. Amer. Philos, Soc., 1878, p. 186, 
