G. R. Wielancl — Upper Cretaceous lurtles. 437 



The Plastron. 



Greatest length on Greatest 



medium line. width. 



Epiplastron 



Entoplastron 4*3 4*5 



Hyoplastron .. 6*0 10* 



Hypoplastron .__ .6*2 9*5 



Xiphiplastron 7* ± 3*3 



(Greatest thickness of the hyoplastron measured on interior 

 border 2*7 cm , of the hypoplastron 3'l cm . Least width of hyo- 

 plastron measured across axillary border 5*6 cm , of the hypoplas- 

 tron across the femoral border 5 cm , — whence least width of 

 bridge, 10'6 cm .) 



7 



Figure 7. — Agomphus tardus (type), x %. Outline of sutural faces (or 

 transverse sections) of the hyoplastron, the hypoplastron, and the 5th mar- 

 ginal, h. h. posterior and internal sutural face of hypoplastron ; hp, inter- 

 nal sutural face of hypoplastron, which placed tandem to h yields the median 

 transverse section of the plastron, exclusive of the epi-, the ento- and xiphi- 

 plastron ; 5, anterior face, 5th marginal. The arrows orient to the vertical 

 and median lines. 



Agomphus masculinus Wieland (sp. nov.) — (Figure 8). 



The beautifully fossilized plastron accompanied by various 

 marginals, a nuchal and fragmentary pleurals of a smaller 

 turtle than the preceding, received at the Yale Museum from 

 the West Jersey Marl Co.'s pits, at Barnsboro, Gloucester 



