292 



A natural grouping of the species is, however, possible, and the 

 American species can naturally be united into well defined groups 

 (subgenera or even genera), the peculiarities of which are found in 

 a row of common characters; some of these seem to be of small 

 importance, but their stability is without question. 



In a later paper I shall try to group the American species of 

 Drt/opteris, here I shall only point out, how minute and very often 

 overlooked characters may be used as generic marks, when several 

 of them constantly occur together. Among the American species of 

 Dryopteris I find a little series of species, which are so uniformly 

 different from all others that I am convinced that they must be 

 separated from Dryopteris and referred to a new genus, which I 

 have here the pleasure to propose. Below I shall in some details 

 mention the generic characters, which are not, as will be seen, 

 characters, which hitherto have been considered of generic value. 



Stigmatopteris gen. nov. 

 {Phegopteris § Stigmatopteris Mett. msc. in Hb. Berol.) 



Genus Dryopteridearum soris superficialibus dorsalibus, globosis 

 vel parum oblongis, exindusiatis; venis liberis vel irregulariter ana- 

 stomosantibus marginem non attingentibus apicibus supra promi- 

 nulis clavatis. Lamina pilis omnino destituta sed ad stipitem, 

 rachin costasque ^ squamosa, pellucido-punctata. Sporangiis longe 

 pedicellatis, sporis ovalibus vel subreniformibus, maturis anguste 

 episporiatis. 



To this short diagnosis I shall add the following remarks. 



All species of the genus, known to me, are exindusiate, thus 

 belonging to the old genus Phegopteris. In some andine forms are 

 found, however, a "false" indusium, a lacerated scale, in structure 

 hke those of the costse, but fixed laterally to the receptacle and 

 protruding beyond the sporangia. Sodiro, who mentions this 

 pseudo-indusium (Cr. vase. quit. 295, under P. ichtiosmum), com- 

 pares it to the inferior indusium of Cystopteris, which however is 

 a true indusium covering the sporangia before maturity, which is 

 not the case in Stigmatopteris. In S. Michaelis the receptacle 

 bears a number of articulated, brown paraphyses, which are 

 longer than the sporangia. These paraphyses have fully the aspect 

 of being undeveloped or rudimentary sporangia. The sporangia 

 are furnished with a long, articulated pedicel, and they show a 



