Il6 SMITHSONIAN MISCELLANEOUS COLLECTIONS [vol. 50 



This form was placed by its author among the ferns and compared 

 especially with the living Platycerium, 



The next species in point of time is Protorhipis asarifolia, de- 

 scribed in 1865 by Zigno, 1 from the Jurassic (Oolite) of Italy. It 

 is very much smaller than the type species, being only about 3 cm. 

 in diameter. It is nearly circular in outline, deeply kidney-shaped 

 at base, and has the margins perfectly entire ; it was also placed 

 among the ferns. 



In 1878 Nathorst 2 described two small forms from the Jurassic 

 (Rhetic) of Bjuf, Sweden. At first he inclined to refer one to P. 

 buchii of Andrae, but later described both as new, under the names 

 P. crcnata and P. integrifolia. They are much smaller than the type 

 species, and were also regarded as belonging among the ferns. 



Two years later Heer 3 described his P. reniformis from the 

 Oolite of Siberia, this being a small reniform, entire-margined species 

 strikingly similar to Zigno's P. asarifolia. In 1882 the same author 

 described another species, under the name of P. cordata* from the 

 Koine beds (Urgonian) of Kome, Greenland. It also belongs to 

 the same group with P. reniformis and P. asarifolia. 



In his final paper on the Mesozoic floras of Portugal, published in 

 1894, Saporta gave complete descriptions and figures of his curious 

 and in some ways anomalous Protorhipis choffatif which comes 

 from the Urgonian of Cereal. It is very different from the forms 

 previously referred to Protorhipis, and, as he suggests, has a rather 

 striking resemblance to certain bracts, stipules, or involucral expan- 

 sions of some angiosperms, as well as to certain ferns, such as Platy- 

 cerium. Its nature and position can hardly be considered as settled. 

 In the same paper 6 Saporta took occasion to describe and figure a 

 very fragmentary specimen from Bjuf, Sweden, submitted to him by 

 Nathorst, under the name of Protorhipis uathorstii. It is too im- 

 perfect to admit of very careful diagnosis and may very probably 

 belong to some of the forms of this or the related genus, Hausmannia, 

 alreadv described from those beds. 



1 Fl. Foss. Form. Oolithcae, vol. 1, 1865, p. 180, pi. ix, figs. 2, 2ei. 

 2 F1. v. Bjuf, pt. 1, p. 42; pt. 11, p. 57, pi. xi, figs. 2, 4. 



3 Mem. Acad. Imp. d. St. Petersbourg (7 ser.), vol. 27 (Fl. Foss. Arct., vol. 

 6, Abth. 1, pt. 1), 1880, p. 8, pi. 1, fig. 4<j. 



4 Fl. Foss. Arct., vol. 6, Abth. 2, p. 10, pi. 111, fig. 11. 



5 F1. Foss. Portugal, 1894, p. 144. pi. xxn, figs. 9-1 1 ; pi. xxvi, figs. 17, 18; pi. 

 xxvii, figs. 1-5. 

 6 Op. cit, p. 143, pi. xxn, figs. 14, 14a. 



