MARYLAND GEOLOGICAL SURVEY 799 



structure (e. g., Androvettia} their reference to this genus would seem 

 hazardous. The entire specimens are strikingly like some of the forms 

 of Protophyllocladus subintegrifolius (Lesquereux) Berry of the Magothy 

 formations, or like Protophyllocladus polymorphus (Lesquereux) Berry 

 from higher western American horizons, and even the compound specimens 

 have an unlobed apical portion of comparable length which is also similar 

 in appearance to the two species just mentioned. The compound forms 

 are superficially like Thinnfeldia rhomboidalis Ettingshausen, 1 the type 

 of the genus Thinnfeldia, whose systematic position has been the occasion 

 of so much controversy and which has been variously regarded as a fern, 

 a cycad, or a conifer. The present species shows important differences, 

 however, aside from its much younger age, and it is confidently believed 

 to be unrelated to the various older Mesozoic species of Thinnfeldia that 

 have been described. 



It may also be compared with various forms from the Upper Cre- 

 taceous of Dalmatia which were discussed at great length by Kerner, 2 who 

 refers them to the genus Pachypteris. This he regards as cycadaceous in 

 nature, but it is believed to be closest to Protophyllocladus subintegri- 

 folius, a species which is abundant in the Atane beds of Greenland, the 

 Dakota group of Kansas and Nebraska, the Raritan of New Jersey, and 

 the Magothy from Marthas Vineyard to New Jersey, and which often 

 assumes a sublobate form. This is especially shown in unreported col- 

 lections made by the writer in the Magothy formation of New Jersey. 



The present species is present in the Magothy formation and frequent 

 in the Middendorf beds of South Carolina. The latter occurrences will 

 be fully described and illustrated in a forthcoming professional paper of 

 the U. S. Geological Survey. 



Occurrence. MAGOTHY FORMATION. Round Bay, Anne Arundel 

 County. 



Collection. Maryland Geological Survey. 



1 Ettings., Abhl. Geol. Reichsanstalt, Bd. iii, p. 2, pi. i, figs. 4-7, 1852. 



2 Kerner, Jahrb. Geol. Reichsanstalt, Bd. xlv, p. 39, 1896. 



