SOME NEW DEVONIC FOSSILS 



209 



umbonal region the lines are close together but they spread out- 

 ward and the primar}' interspaces become broad. The body of the 



Pterin ea brisa 



valve shows few concentric lines but these are strong on the wings 

 and those on the posterior wing are cancellated by the radii near 

 the hinge. 



Lower Devonic. Edmunds Hill, Chapman Plantation, Me. 



Pterinea brisa var. vexillum nov. 



A right valve is suberect with a semicircular lower margin, deep 

 byssal sinus, short but well defined anterior wing and broad pos- 

 terior wing extended to an acute posterior angle. Its surface is 

 flat or slightly concave in the pallial region. The sculpture con- 



^: 





y 



Pterinea brisa var. vexillum 



sists of fine radial riblets of subequal size moderately distant and 

 numerous over the body of the valve, very obscure on the posterior 

 wing, which is entirely covered by concentric crowded lamellose 

 lines ; the latter are extremely faint over the rest of the shell. A 

 less complete specimen in which the left valve is impressed upon 

 the right shows that the surface of the latter was crossed by very 

 strong radial and very distant ribs, the broad flat interspaces some- 



