194 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvii. 



METOPOSAURUS FRAASI, new species. 



Type. — An episternuiu, No. 2152, catalogue of fossil vertebrates, 

 U. S. National Museum, from 5 miles east of Tanners Crossing, Little 

 Colorado River, Arizona. This locality is about 25 miles above the 

 junction of the Little Colorado with the Colorado. The specimen is 

 shown on Plate III. 



The species is characterized by the coarseness of the sculpturing of 

 the episternum and the fact that the markings of the center of the 

 plate consist of irregular pits which, toward the margin, are trans- 

 formed into radiating grooves. These grooves are most marked on the 

 anterior portion of the bone. The portions of clavicles present also 

 have the ornamentation in the shape of pits rather than as grooves, and 

 in this respect and in the greater coarseness of the sculpture the present 

 species differs from the European Metoposaurus dlagnostlcus of von 

 Meyer. It is furthermore characterized b}^ the extent of the articu- 

 lation of the clavicle with the episternum, the posterior end of the 

 clavicle being well behind a line drawn through the center of the plate. 

 The postero-internal angle of the clavicle is very much rounded instead 

 of being decidedly angular, as it is in Metoposaurus dlagnostlcus. 



The episternum is 43 cm. (16f inches) long and 30 cm. (11|^ inches) 

 wide. 



The only other specimen that can be referred to this species is the 

 anterior portion of a left mandible, somewhat weathered, found at the 

 same locality as the episternum. This mandible is coarsel}' sculptured 

 on the external face, and bears indications of two large teeth at the 

 very front of the ramus, and behind these 15 small teeth. These 

 seem to have been largely attached to the external wall of (he alveolus 

 in a manner somewhat suggestive of the pleurodont dentition of an 

 iguana. 



From the same Triassic beds, though at some little distance from 

 the locality where the episternal plate of Metoposaurus was obtained, 

 Mr. Brown secured a number of fragments which, when put together, 

 proved to be the humerus of a large Anomodont, or, more sti'ictl}^ 

 speaking, Cotylosaurian. This represents a new species and new genus 

 for which the name of Plucerlus liesternus is proposed, the generic 

 name being given on account of the breadth of ])ody indicated b}- the 

 short, broad humerus. 



PLACERIAS, new genus. 

 PLACERIAS HESTERNUS, new species. 



•' Type. — A right humerus, No. 2198 catalogue of fossil vertebrates, 

 U.S.N.M., from 3 miles north of Tanners Crossing of the Little 

 Colorado River, Arizona. The specimen is figured on Plate IV. The 

 characteristic features of the genus and species are the great and sudden 

 expansion of the deltoid ridge, the contraction of the humerus at the 



