A REDESCRIPTION OF PARJOTICHUS 

 INCISIVUS COPE. 



E. C. CASE. 



A\ unusually perfect specimen of this genus and species 

 in the paleontological collection of the University of Chicago 

 makes it possible to complete the description of the species, 

 hitherto known only from a fragmentary skull, and to add some 

 points to the characters of the genus, also known largely from 

 the skull. 



The i2ixm\y Pariotichidae was established Iw Cope in 1883 (3). 

 He says (p. 631) "Pariotichus and Paiitylus and probably Ecto- 

 cy7iodon must be referred to a special family, the Pariotichidae, 

 which has teeth like the EdapJiosaitridae but differs from it in 

 the entire over-roofing of the temporal fossae." There is no 

 mention here of the family belonging to the order Cotylosatiria, 

 but this is evidently the position in which he would have placed 

 it, as it is regarded always in later writings as belonging in that 

 order or suborder, as he then regarded it. 



In 1895 he gave a tabular statement of the characters of the 

 families in the order Cotylosauria (4) : 



I. Teeth in a single series. 



Teeth not transversely expanded ; vertebral centra 



with surfaces only ossified ; no hyposphen. . . Elginiidae. 



Teeth not transversely expanded ; vertebral centra 



ossified ; no hyposphen Pariasauridae. 



Teeth with the crowns transverse to the axis of the 



jaws ; vertebrae ossified and with a hyposphen- 



hypantrum articulation Diadectiaae. 



II. Teeth in more than one series in (one or) both jaws. 



Teeth with cylindric roots ; vertebrae ossified. . . Pariotichidae. 



In 1878 (i) the ger\us Pa7'iotichus was described (p. 508): 

 "The temporal fossae were covered by a roof continuous with 



