i8o University of Texas Bulletin 



9-12. The principal difference between our species and the Triassic 

 species is that the latter shows a serrated first lateral lobe in a speci- 

 men of about 16 mm. diameter, while the lobes in ours are apparently 

 all rounded. 



The different species of Paraiecanites described by Diener-* are all 

 less evolute and the dorsal portion is broader, which would account for 

 the difference in the suture. 



Age: 



Leonard formation, Permo-Carboniferous. 



Number of specimens examined: 



Fourteen. The species appears to be very frequent at the locality 

 but it is never very well preserved. 



Locality: 



South of the intrusive plug on Capt. James's ranch, Altuda Moun- 

 tain, near Marathon." 



'Diener, Amm. u. Orthoc. i. siidtirol, Bellerophonkalk, p. 68-71, pi. 1, fig. 3-8. 



