126 Proceedings of the Biological Society of Washington. 



quitz, Alta Verapaz, Guatemala, altitude 350 meters, August, 1900, by 

 H. von Tiirckheim (John Donnell Smith, no. 7806). There are at hand 

 three additional specimens from the type locality, collected by von Tiirck- 

 heim in October, 1906 (II. 1454); these agree perfectly with the type and, 

 like that, are wholly fertile. There are also referred here four specimens, 

 consisting of large sterile pinnae, collected near Cordoba, Veracruz, Mexico, 

 1889 to 1891, by Hugo Fink (no. 5). They differ slightly in having more 

 numerous bullate scales at the base of the segments beneath and the veins 

 mostly with two pairs of branches; but these doubtless are only vegetative 

 characters directly associable with sterility. 



Alsophila scabriuscula is nearest related to A. mexicana Mart, and A. 

 bicrenata (Liebm.) Fourn., of the same general region. The former species, 

 usually known as A. Godmani Hook., differs in having the segments truly 

 pinnatifid, and both the primary and the secondary rachises furnished 

 with occasional large, flat, persistent, white scales; and the latter species, 

 has much smaller, narrower pinnules, the segments glabrous above, and 

 the costules beset with numerous persistent, white, bullate scales beneath. 

 It is hardly to be doubted that the trunks and stipes would furnish good 

 diagnostic characters also, but these are the parts usually neglected by 

 collectors. 



