600 NEW YORK STATE MUSEUM 



to Fontaine's Sapind op sis variabilis; and Prof. 

 Ward 1 appears inclined to concur in this opinion. The plant 

 from the upper Devonic of America evidently is neither con- 

 generic with Sternberg's type nor in conformity with his 

 diagnosis. 



Since the virtual abandonment of Sternberg's original type, 

 Goppert's species, Haliserites dechenianus, which 

 presents a far closer resemblance to the living Haliseris 

 (Dictyopteris) has generally been made to serve as the type of 

 the genus not only among Paleozoic forms, but even among 

 Mesozoic species. 



The name Haliserites dechenianus was first ap- 

 plied 2 to a plant from the Spirifer sandstone, lower Devonic, 

 of Nassau. With his final description of the species Goppert 8 

 quotes Sternberg's generic diagnosis verbatim. The Nassau 

 species he describes as having flat fronds, alternately dicho- 

 tomously ramose, the branches and branchlets linear, of equal 

 width, and sometimes ciroinnate, the costae being median. 

 The form and proportions of Goppert's plant, specially in the 

 fragments shown in pi. 2, figs. 3 and 4 of his Flora are so similar 

 to the corresponding features ofThamnocladus clarkei 

 as at first to make it seem that the plants are specifically iden- 

 tical. Against this, however, stand the apparently membrana- 

 ceous texture, and the generally sharply prominent costa, which 

 even appears to be partially torn free in one 4 of the Nassau 

 types. With these differences in mind it becomes apparent 

 that, as artificial genera are commonly understood, Goppert's 

 plant can hardly be considered as congeneric with that from 

 Meshoppen except we conclude it was wrongly described, and 

 that it is not membranaceous, not circinnate, and probably not 

 flat. 



1 U. S. geol. sur. Monogr. 1895. 26:96. 



2 N. Jahrb. f . Min. 1847. p. 686. Jahresb. d. Ver. f. Naturk. in Herzogth. 

 Nassau. 1851. 7th Heft, 1st Ajbth. p. 141. 



3 Fossile Flora des Uebergangsgebirges. 1852. p. 88, pi. 2; see also Nova 

 Acta Acad. C. D.-C. Nat. Our. Sup. 1859. 27:442. 



4 Loc. cit. fig. 3. 



