NOTES ON THE LEPIDOCARPACEAE 553 



characters by which it can be recognized, but at present its true distinguishing 

 characters are not known. More thorough examination of Lanarkian forms will 

 probably also result in additional species being recognized, as suggested by Scott 

 and others who have examined many "Lower Coal Measures" specimens. 



For convenience L. lomaxi, L. wildianum, and closely related but as yet 

 undistinguished forms of Lower Carboniferous and Lanarkian age will be 

 referred to as the lomaxi group. Because they possess certain characteristics 

 reminiscent of those of free-sporing lycopsids and, in addition, because of their 

 antecedent stratigraphic position relative to the American species, they are 

 regarded as examples of the more primitive lepidocarp stock. 



In 1914 Kidston described Lepidocarpon westphalicum from the Yorkian 

 age ironstone deposits near Dudley. The type consists of an axis with scars 

 of sporophylls previously shed and a central portion on which parts of about 

 twenty attached sporophylls are visible. The cone is of compact construction 

 and is preserved without crushing, but only surface features were observed and 

 these are not all that might be desired The laminae may be of moderate length 

 and appressed to the cone, judging from Kidston's Figs. 1, 3, 4, and 5, where 

 they seem to appear in lengthwise fracture on both sides of the specimen. 

 Kidston states that the "whole of the bracts have disappeared" and so the 

 laminae, apparently seen, may be illusory. The laminae, however, may have 

 been membranaceous distally, similar to those of L. lomaxi described by Scott. 

 The particular feature that decided Kidston on the generic identification of 

 this species was the sporangial integument, but he did not note a micropylar 

 slit. So far as known the integument appears generally similar to that of L. 

 lomaxi. Most of the sporangia have their disal ends exposed, and on many of 

 these a small terminal irregularity appears which should be opposite the trilete 

 apparatus of the seed megaspores inside them. 4 No remnants of the se.ee! 

 megaspores have been reported in Lepidocarpon westphalicum although they 

 may be present. There are no very definite biological characters distinguishing 

 L. westphalicum from members of the lomaxi group except for differences in 

 size. The cone is about 15 mm. in diameter in contrast to 20-30 mm. for L. 

 lomaxi; tn*» sporangia are smaller and have a height-breadth ratio of l 1 ^ to 1 

 whereas in L. lomaxi the ratio is slightly less than 2 to 1. 



Records of American Lepidocarpaceae 



Lepidocarpon was first reported in America by Noe (1931) in a list com- 

 piled from investigations by certain of his students. A discussion of this 

 material was included in Miss Krick's (1932) report on seed-like fructifica- 

 tions from the Harrisburg (No.5) coal in Illinois. Later Fredda Reed (1936) 

 described other isolated Lepidocarp sporophylls from the same source. The 

 presumptive evidence that these specimens belong to Lepidocarpon is good, 

 but it can not be considered entirely conclusive because the manner of pedicel 



4 These may be the "smooth pits at the basal end" which Darrah (1941, p. 87) 

 refers to as sporangial attachment marks but this interpretation is not indicated by Kid- 

 ston's discussion. 



