KNOWLTON] KOOTANIE PLANTS FROM GREAT FALLS, MONTANA 117 



The genus Hausmannia, instituted by Dunker, 1 in 1846, from an 

 imperfect leaf from the Wealden of North Germany, is also involved 

 in the present complication. The type species, and apparently the 

 latest species to be referred to Protorhipis, is Dictyophyllum roemeri 

 Schenk, which is recorded by Seward 2 from the Wealden of Bernis- 

 sart, Belgium, under the name P. roemeri. It is a mere fragment 

 and can have no value one way or the other. 



H. dichotoma is very different in appearance from Protorhipis 

 buchii, the type of the former genus being palmate and deeply divided 

 into lobed linear segments, which are traversed by forked main veins 

 from which anastomosing branchlets are given off. A number of spe- 

 cies were subsequently described under this generic name and which 

 conform to the original generic diagnosis, but in 1892 Bartholin 

 described from Bornholm, as Hausmannia forchhammeri, a number 

 of specimens that were obviously the same as Protorhipis buchii. 

 In commenting on this paper, Zeiller 3 took occasion to state that he 

 had received additional material from the type locality of Protorhipis 

 buchii Andrae, which he identified with that species ; this material he 

 illustrated by a number of good photographs. He states, and the 

 figures certainly bear him out, that this new material shows the 

 species to be deeply bilobed or cut quite after the manner of living 

 Dipteris fronds, to which they are certainly most closely related ; 

 and, further, that while apparently differing markedly from Andrae's 

 type specimens, it simply proves that species to be polymorphous, 

 some leaves agreeing with the type and others showing more or less 

 lobing or cutting. If this be true, there is obviously no ground for 

 maintaining the genus Protorhipis, as Hausmannia has priority, and 

 this is the view adopted by Moller, 4 who has recently worked over 

 the Bornholm flora. He describes and figures at length the Haus- 

 mannia forchhammeri of Bertholin, and specially a new form of it 

 which he denominates subspecies dentata. The latter is evidently 

 similar to the type of Protorhipis bucJiii, while the other forms re- 

 ferred to H. forchhammeri exhibit to a greater or less extent the 

 lobing supposed to be characteristic of Hausmannia. It may be that 

 we really have here a highly polymorphous aggregate, as indeed 

 Saporta suggested, one portion of the plant, or one stage in its 

 growth, showing rounded, unlobed, and at most dentate-margined 



1 Monog. Norddeutschen Wealdenfl., 1846, p. 12, pi. v, fig. 1. 



- Mem. Mus. Hist. Nat. Belgique, vol. 1, 1900, p. 18, pi. in, fig. 34. 



3 Rev. Gen. d. Botanique, vol. 9, 1897, p. 51 (reprint), pi. xxi, figs. 1-5. 



4 Kongl. Fysiogr. Sallsk Handl., vol. 13, 1902, p. 48. 



