FOSSIL FOOTPRINTS OF THE JFRA-TRIAS. 



489 



Tin 111. Length of foot exclusive of hallux, .168 m. ; with the hallux,? .195 m. Length 

 of step, .440 ni. Other specimens than the type show measurements somewhat in excess 

 of those given above. 



This is a very numerous and variable type, in .size between Aurhisaiirijjus danumis 

 and A. exsertii.'i, with no marked peculiarities other than size to distinguish it from either. 

 The type specimen, no. f^, of the Hitchcock cabinet, a superb track, has unfortunately 

 been trimmed in such a way as to destro}' the 

 impression of the first claw, but the Imsal pad of 

 the hallux is clearly impressed. It is figured in 

 the Ichnology on plate 57. figure 8. Specimen 

 no. ^, while somewhat larger, gives all of the 

 characters, including the hallux. 



Type, no. ||, of the Hitchcock cabinet, on red 

 shale from Turner's Falls, Massachusetts (fig. 6) . 



Anchisauripus exsertus (K. Ilitchcotk). 



Bronfozoiim exaertidn E. Hitchcock, '58, p. 07, 

 pi. l-l, fig. 1 ; pi. 40, fig. .3. 



Specific characters. Based on no. ^. Divari- 

 cation of digits I and II, 75° ; of II and III, 20° ; 

 of III and IV, 20°. Length of digit I, .075 m. ; 

 of II, .117 m. ; of III, .161 m.; of IV, .15.S m. 

 Length of foot, exclusive of hallux, .226 in. ; 

 including the hallux, .265 m. Length of step in 

 uo. ^ (a somewhat larger specimen), .922 m. 



The real distinction between this species and 

 A. tuherosus seems to be one of size only, for 

 the character which gives the name " exsertus,'" 



that of the unusual projection of the middle toe Fi-. 7. Anchisauripus exsertus E. Hitdifiock. 



beyond the lateral ones, is not always manifest. luipiint of tiie left pes. x k. From no. ii. of the 

 This species is correlated with A)n»iosai(n(s inajor 

 Marsh ('96. p. 147, pi. o, fig. .3-6). 



Type specimen, no. ^, of the Hitchcock cabinet, on gray micaceous sandstone from 

 Smith's Ferry, Massachusetts (fig. 7, of no. — ) . 



Hitclifock cabinet. The bone re.storation is after 

 that by Marsh of Amniosaurns major Marsli. 



