Fig. 41. 



Fig. 42. 



Figs. 41, 44, and 45, magnification, 72 x . Figs. 42 and 43, magnification, 300 x . Fig. 41, 

 etched with ammonia and hydrogen peroxide, followed by acidified ferric chloride. Figs. 

 42, 43, 44, and 45, etched with acidified ferric chloride. 



Am. Jour. Sci. — Fourth Series, Vol. XL, No. 240. — December, 1915. 

 41 



