r 



FHE AMERICAN 



/// 



MONTHLY 



Microscopical Journal: 



CONTAINING 



CONTRIBUTIONS TO BIOLOGY. 



Volume XL 



FOU 



1 890. 



FOUNDED IN 1880, BY ROMYN HITCHCOCK, F. R. M. S, 



PUBLISHED. SINCE 1887, BY CHAS. W. SMILEY, 



WASHINGTON, D. C, 



