FOSSIL VERTEBRATES— REPTILIA 523 
to a pointed rostrum in front; the orbits were large and the 
anterior nares very small; the posterior part of the skull shows 
the presence of the fossae already mentioned. The teeth are 
the most striking features of the skull, the anterior incisors were 
chisel-like and prehensile; the mawillaries were broad and flat ; 
there were five on each side; besides the maxillary teeth there 
were three large palatine teeth on each side, so large that they 
covered nearly the whole roof of the mouth. The broad, low 
teeth of both this and the succeeding forms seem to indicate 
that the animals were accustomed to a molluscan diet. 
Cyamodus was very similar to Placodus, but there were no 
prehensile incisor teeth and there were five palatine teeth, the 
posterior pair far exceeding the anterior ones in size. 
ie Gy CASE, 
REFERENCES. 
ZITTEL, KARL VON: Handbuch du Paleontologie. Paleozoologie III. Bd. 
Cork, E, D.: Origin of the Fittest. New York, 1887. 
Cork, E. D.: Primary Factors of Organic Evolution. Chicago, 1896. 
OWEN, RICHARD: Description and Illustrated Catalogue of the Fossil Reptilia 
of South Africa. London, 1876. 
LYDEKKER, R.: Catalogue of the Fossil Reptilia and Amphibia of the British 
Museum, Vols. I-IV. London, 1888-1890. 
