76 
previously recognised in the Stegocephalian jaw, but Watson believes ~ 
that an anterior bone usually called „Splenial“ is really the Coronoid 
and has named the posterior bone the Epicoronoid. The condition 
in Eryops and Trimerorachis clears up the confusion. In Eryops 
there is a typical Coronoid round the front of the supra-meckelian 
fossa. It carries a large number of small teeth and passes forward 
half way to the symphysis. At its anterior end it articulates with a 
second flat bone which passes forward to near the symphysis, between 
the Splenial and the tooth bearing portion of the Dentary. In 
Trimerorachis the Coronoid is very similar to that in Eryops, but the 
anterior bone, though present, is very much smaller. Its position and 
S === Part. 
\ 
A, 
Fig. 3. Mandible of Sauripteris taylori, Hatz. About !/, nat. size. The front 
half of the jaw is restored from Fraquair’s figure of the closely allied genus 
Rhizodopsis. A. Outer side. B. Inner side. 
size are indicated in the figure given. This anterior bone is the one 
that has been confused with the Splenial. Branson in his figure of 
Eryops jaw shows it attached to the Prearticular. In Anaschisma 
he shows it extending backward to supra-meckelian fossa. There can, 
I think, be no doubt that the bone regarded by Branson as the 
Coronoid is rightly identified. Warson’s objection that it is difficult 
to imagine the small Coronoid of such a type as figured by Branson 
extending far forward may be answered by pointing out that even 
in Eryops the Coronoid is not a small bone as figured by Branson, 
