144 



THE EXTINCT BATRACHIA, KEPTILIA 



In. 



Lin. 



2 



1.5 



1 







7 



2 



4..", 



1 









!) 



1 



9 



1 





5 





1 



11 





2.5 



The vascular grooves are quite distinct, forming short, straight and zigzag, sometimes crossing grooves. In the 

 posterior or wider marginals, the upper inner margin is produced inwards above the lower. The rib pits are round. 

 None of the marginal hones have recurved edges. 



Measurements. 

 Width of a posterior marginal, 

 Depth " " " within, 



Depth " an anterior " at edge, 



Length " " " 



Width " 



Width of dermal scute; on same, 

 Width of middle marginal, above 

 Width " " below 



Length of costal bone on curve, 

 Width " 

 Thickness of costal bone at middle margin, 



The specimens on which this species are based were obtained from the pits of the West Jersey Marl Company, 

 near Bamesboro, Gloucester county, New Jersey, and were presented to the author by I. C. Voorhees, Superin- 

 tendent there. 



LYTOLOMA, Cope. 



This genua is more like Chelone than any of tin; Chelydrine forms here described. 

 The characters are derived solely from portions of the carapace which are preserved, and 

 arc as follows : 



The marginal hones free from the carapaee except at the anterior and posterior por- 

 tions, narrow anteriorly, expanded behind. 



The evidence for these characters consists : first, of a median and a first marginal bone 

 of a species from the green sand of Bamesboro ; second, of two marginals and a mandi- 

 bular arch from Birmingham ; third, of four consecutive posterior marginals from Mullica 

 Hill; fourth, of parts of a skeleton from Hornerstown. The first represents the Chelo- 

 nioid freedom of all but the nuchal marginal plate, in front, by the entirety of the margins of 

 the first. The second presents a, free anterior marginal, and a narrow middle marginal 

 with rib pit. The third probably belonged to the same species as the last, and presents 

 in the inner margins an absence of the disposition to expansion, which exists in the genus 

 Osteopygis, where the union of disc and marginals is extensive. It appears to have been 

 similar to the genus Propleura in the posterior part of the carapace. 



Two species of the genus appear to be indicated by the material at my disposal, which 

 can be thus distinguished. 



The anterior (first and probably second) marginals with entire convex margin. 



L. JKANKKII. 



The anterior (second and probably first) marginals with openly emarginate margin. 



P. ANGUSTA. 



