58 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8o 



whereas the hindfoot is directed straight forward (see fig. 26). The 

 relative lengths of the digits are given in the table of comparative 

 measurements (see p. 57). The form of the elongated hindfoot im- 

 pression has a considerable resemblance to the pes track of Baropus 

 lentus Marsh (see fig. 10), but is distinguished from that genus by 

 the presence of five toes and in having the forefoot considerably 

 smaller than the hind, and its much smaller size as a whole. 



Genus COLLETTOSAURUS Cox 



CoUettosaiinis Cox, E. T., Fifth Ann. Rep. Geol. Surv. Indiana, 1874, p. 247, 

 one plate. 



In reviewing the literature relating to Carboniferous footprints it 

 became at once apparent that many of the authors gave but scant 

 attention to the work done by their predecessors, a procedure that has 

 resulted in the creation of a number of synonyms. While it is far 

 beyond the scope of the present paj3er to attempt a revision of the 

 entire subject, in order to secure a working basis for the proper 

 classification of the specimens here considered it becomes necessary 

 to make the nomenclatural changes herewith suggested. 



In 1874 Cox proposed the genus Collcttosaurus based on an ade- 

 quate specimen from the Carboniferous of Warren County. Indiana. 

 No attempt was made to characterize the genus, but from his rather 

 meager description and illustration it may now be defined as follows : 



Generic characters. — Qliadrupedal. Five digits on both manus and 

 pes. Toes relatively slender, acuminate, radiating, with fifth some- 

 what set ofif from the others ; feet about equal in size ; hindfoot placed 

 behind forefoot. 



Genotype. — Collettosaurus indianacnsis Cox. 



In February 1891, Butts* described the new genus and species 

 Notalacerta missouriensis (see fig. 30) from the Upper Coal Mea- 

 sures of Kansas City, Missouri, and in March of the same year he 

 established a second genus Notamphibia magna (see fig. 29), each 

 having five slender sharply pointed toes on both fore- and hind feet. 



A critical comparison of these three genera fails to disclose dift'er- 

 ences of genetic importance, and on the grounds of i^riority Notala- 

 certa and Notamphibia are considered synonyms of CoUettosaiinis, 

 the species to be known hereafter as Collettosaurus Diissouriensis 

 (Butts) and C. magna (Butts). 



' Butts, Edward, The Kansas City Scientist, Vol. 5, 1891, p. 18. 



