NOTES ON THE LEPIDOCARPACEAE 549 



(Lepidocarpaceae) and the other groups of Paleozoic lycopsids because the 

 differences between lepidocarp fructifications and fructifications of all the ftee- 

 spcring lycopsids appear to be valid criteria for at least family differentiation. 

 The foregoing diagnosis of this family is, nevertheless, incomplete because 

 definite knowledge of the vegetative characters is still lacking. It is hardly 

 conceivable that the vegetative organs are wholly unrecognized in the fossil 

 flora, but they are probably classified erroneously at present in some other 

 family. 



The writer suspects that plants classified as Lepidophloios Sternberg 3 may 

 be vegetative correlatives of genera belonging in the Lepidocarpaceae. Lepido- 

 phloios scoticus Kidston is the only species of this genus whose fructification 

 characters have been even partially ascertained. Its cones are borne on special- 

 ized branches, an advanced mode of fructification not characteristic of Lepido- 

 strobus or lepidodendrids in general. Nothing whatever is known, however, 

 of the spores produced by these cones. L. scoticus is restricted to the Lower 

 Carboniferous, the cones being known from oil shales of the Calciferous Sand- 

 stone series in Scotland. At other localities and horizons the only evidence as 

 to Lepidophloios fructifications still has to be deduced from association of 

 disconnected fruiting structures. The lepidocarps, although they generally have 

 passed unrecognized, appear to be among these associated types. In America 

 Lepidophloios seems to be the only well represented group of lycopsids whose 

 mode of fructification is so obscure. The lepidocarps, on the other hand, do 

 not seem to have as plausible affinities with any other group based on vegeta- 

 tive characters. 



The fact that the Lepidocarpacaceae and Lepidophloios coincide in their 

 time range, both being limited to the Carboniferous and both being reasonably 

 well represented throughout these beds, is perhaps as definite a point of 

 evidence as can be cited now. Lepidophloios aff. L. laricinus (Sternb.) Stern- 

 berg is a characteristic species found in roof shales over the Herrin (No. 6) 

 coal which, in addition to the Mazon horizon, has also provided specimens 

 assigned to Lepidocarpon mazonense Schopf. A form identified by Lesquereux 

 as Lepidophyllum auriculatum (probably Lepidocarpon), was found at St. 

 John (Perry County, Illinois, above No. 6 coal) closely associated with a 

 species of Lepidophloios which Lesquereux (1870, p. 432, 439; 1880, p. 422, 

 450) identified by the same specific name. He considered that the two species 

 probably were correlated. Lepidophloios ranges through the English Lanarkian 

 (which includes the "Lower Coal Measures") and is characteristic of the 

 Lower Carboniferous where it is associated with Lepidocarpon (Walton 1935; 

 Walton, Wier & Leitsch 1938). Other occurrences need not be cited here but 

 the apparent association of these fossils may be significant. 



Correspondence that passed between the late Professor A. C. Noe and W. 

 Hemingway of Derbyshire, England, concerning a shipment of sections sent 



3 Sternberg's original spelling of this name was "Lepidofloyos." There is a question 

 whether the original spelling, or the now accepted "correction" of it should be used. I 

 am indebted to Dr. F. C. MacKnight for calling this to my attention. 



