740 CRETACEOUS PALEONTOLOGY. 



1876. Pyropsis elevata Gabb, Proc. Acad. Nat. Sci. Phil. 



(1876), p. 284. 

 1876. Pyropsis Richa\rdsoni Gabb, Proc. Acad. Nat. Sci. Phil. 



(1876), p. 284. 

 1883. Pyropsis perlata Tryon, 'Struct, and Syst. Conch., vol. 2, 



p. 141, pi. 51, fig. 61. 

 1892. Pyropsis elevata Whitf., Pal. N. J., vol. 2 (Monog. U. 



S. G. S., vol. 18), p. 35, pi. i, figs. 11-13. 

 1905. Pyropsis elevata Johns., Proc. Acad. Nat. Sci. Phil. 



(1905), p. 23. 

 1905. Pyropsis perlata Johns., Proc. Acad. Nat. Sci. Phil. 



(1905), p. 23. 

 (Not P. richardsoni or P. perlata Whitfield, Pal, N. J., 



vol. 2 (Monog. U. S. G. S., vol. 18), pp. 37 and 39, 



pi. i, figs. 8-10, and pi. I, figs. 14-16.) 



Description. The dimensions of the type specimen of P. per- 

 lata are : total height, restored, about 50 mm. ; maximum diam- 

 eter of body volution, 35.5 mm.; approximate length of anterior 

 canal as restored, 26 mm. Shell somewhat pyriform, spire low, 

 the apical angle about 135. Body volution very wide, the upper 

 surface flat or slightly concave towards the periphery ; periphery 

 carinate, the keel uneven, being produced at intervals into low 

 somewhat compressed tubercle-like processes; lower side of the 

 volution convex above, becoming concave below where it is pro- 

 duced rather abruptly into the long anterior canal. Surface 

 of the outer volution marked with revolving costae, about seven 

 or eight of which, alternating in size, occupy the upper flattened 

 surface; below the periphery and about one-third the height of 

 the body volution, exclusive of the canal below it, is a strong 

 revolving, subcarinate ridge, elevated at intervals into low 

 tubercle-like processes ; between this strong rib and the periphery 

 are three costse, the middle one of which is the stronger, all of 

 which are more or less crenate; below the strong subperipheral 

 rib a series of more or less crenate revolving costae continue 

 downward to the anterior canal, gradually becoming smaller 

 below. The surface is also marked by more or less conspicuous, 

 transverse lines of growth. 



