LYCOPODIALES— EUSIGILLAEIxE— SIGILLAEIA. 243 



many paleontologists, among- whom is Professor Zeiller,^ the two species 

 are nnited by most authors, including Professor Lesquereux. The latter, 

 however, seems to have so interpreted the character of the species as to 

 make it include a number of forms placed by European paleobotanists in 

 other S]Decies, while assigning to S. mammillaris Brongn. certain tyj^es which 

 appear to harmonize better with the European S. tessellata. 



The genus SigiUaria offers perhaps the best illustration of the difficulty 

 of identifying the fossils of one continent in accordance with the insufficient 

 descriptions, imperfect or often misleading figures, and frequently erroneous 

 nomenclature and synonymy in the earlier literature of another and some- 

 what distant continent. It is no cause for wonder if many of the iden- 

 tifications of material in America made in dependence on the European 

 literature of the first three-quarters of this centurj^ are found on a compari- 

 son of specimens to be faulty. 



Locality. — Jordan's coal mine, U. S. Nat. Mus., 6214. 



SiGILLAEIA OVATA Sauv. 



1848. SigiUaria ovata Sauveur, Veg. foss. terr. houill. Belg., pi. li, fig. 2. 



1886. SigiUaria ovata Sauv., Zeiller, Fl. foss. bassiu houill. Valenciennes, Atlas, pi. 



Ixxix, figs. 4, 5, 5a, 6, 7 (fig. 3 1); text (1888), p. 522. 

 1883. SigiUaria Ussenia AchepoliI, Niederrh.-Westfal. Steink., p. 118, pi. xxxvi, fig. 9. 



Several fragments of stems belonging to the subgenus Bhytidolepis 

 exhibit oval scars of the proportions illustrated by Sauveur under the above 

 name. They are also closely related to forms determined by Professor 

 Lesquereux as 8. mammillaris var. latior and 8. orbictdaris, or still more closely 

 to a new species^ from the Anthracite series of Pennsylvania. 



Until the American material in this genus is somewhat revised it seems 

 impracticable to attempt to point out the specific differences between 

 examples referred to the above-named species and others found in this 

 country. 



Locality. — Jordan's coal mine, U. S. Nat. Mus., 6215. 



■ Fl. foss. bassin houill. Valenciennes, p. 561. 

 -In unpublislied MSS. 



