48:> HICHARD SWANN LULL ON 



Systematic Descriptions. 



Class REPTILIA. 



Subclass DiAPSiDA Osborn.' 



Superorder Diaptosauria Osborn/ 



Order"! PROTEBOSAUBIA Seeley. 



Ordinal chdruetersr Quadrupedal in gait ; nianus generally much smaller tlian the 

 pes and five fingered though all may not always impress. Pes with four digits, generally 

 (linosauroid in form, though plantigrade. Limbs generally long. 



These forms seem to represent survivoi's of the ancient stem from which the dino- 

 saurs arose ; they may, however, represent primitive quadrupedal dinosaurs which had 

 not yet acquired the erect gait. 



Family BATRACHOPODIDAE 



Family characters. The same as those given for the order. Digits of the pes with 

 acuminate claws. 



Genus Batrachopus E. Hitchcock. (Frog foot.) 



Batrachopus E. Hitchcock, '45b, p. 25. 



Anisojms E. Hitchcock, '48, p. 226. 



Anisichwif! C. H. Hitchcock, '71, p. xxi, (to replace Anisopus preoccupied). 



Generic characters. Mauus probably with five, always with four broad clawless 

 digits, generally directed forward. 



Pes four toed ; the hallux non-rotated ; all of the digits bearing slender acuminate 

 claws; that of tlie fourth toe may be absent in the impression, possibly also in the foot; 

 third toe the longest. Manus and pes tracks close together and nearly in a right line. 

 Ratio of track to step, one to seven nearly. 



This genus was included by Hitchcock under tlie Loricoid marsupialoids from its sup- 

 posed likeness to an armored mai'supial. Type species, B. deweyanus, E. Hitchcock. 



'O.sborn. :03a. 



^The charactei-s here given arc based entirely upon the tracks; for further definition of tlie orders, etc., the stiulent is 

 directed to Zittel's Palaeontologie. 



