NOTES ON THE LEPIDOCARPACEAE 559 



Cantheliophorus and Lepidocarpon 



A substantial addition to the Lepidocarpaceae was made by Harvey BassJer 

 (1919) in his description of twelve species under the generic name of Canthe- 

 liophorus, although he misinterpreted the structure of his material. 8 Bassler 

 recognized that his species were highly specialized and his statement (1919, 

 p. 97) that "members of a group with structure as intricate and diverse as this 

 will have high stratigraphic value if treated with great systematic refinement" 

 seems more than ever warranted. 



Lepidocarp sporophylls in shale are preserved differently, depending upon 

 whether the plane of rest is determined by a broad lamina or by the form of 

 the seed body itself. The seed body generally is higher than broad, and if the 

 lamina forms too narrow an appendage, the height of the seed body is most 

 likely to parallel the bedding. All of Basser's species seem to have been pre- 

 served in this position and those he illustrates are compressed parallel to the 

 organic longitudinal plane. Thus they appear much different from most speci- 

 mens of Lepidostrobophyllum in which the laminal breadth more consistently 

 parallels the bedding planes. Although characters of size and proportion of 

 sporophyll laminae are generally considered to be of specific importance, they 

 probably lack generic significance. 



The features Bassler considered to be unique in Cantheliophorus were, (1) 

 two sac-like sporangia per sporophyll, borne on short sporangiophoric stalks; 

 (2) a plate of sterile sporophyll tissue ascending from the ventral midline of 

 the pedicel and to which the sporangiophores were attached laterally and dis- 

 taily. The structures ilustrated, however, do not support this morphologic 

 interpretation of them. They are instead more satisfactorily explained by com- 

 parison with Lepidocarpon, and according to this interpretation they comply 

 entirely with the essential diagnostic characters of that genus. Bassler has not 

 presented evidence proving the existence of two sac-like bodies on any single 

 sporophyll - — he has not shown the "median" plate to be other than the 

 compressed form of the Lepidocarpon integument. 



The "sporangia" of Cantheliophorus agree precisely with seed megaspores 

 of the lepidocarps, and they must be interpreted in this light. It is understand- 

 able how Bassler and others failed to note this resemblance because no lepido- 

 carp megaspores had been isolated previously and they are remarkable objects 

 e.uite different from the common free-sporing forms in general outline and size. 

 Nevertheless the single fertile lepidocarp seed megaspore is clearly recognizable 

 from Bassler's figures for most of the Cantheliophorus species. They agree in 

 habit with those the writer has illustrated from Lepidocarpon corticosum 

 (Schopf 1938a, 1938b, 1940) and also with seed megaspores obtained from L. 

 mazpnense. The agreement with seed megaspores Bocheriski (1936) obtained 



8 Bassler's descriptions are given in terms of his hypothetical interpretation of the 

 sporophylls, but there is no reason for preserving this terminology because his specimens 

 are easily described by other terms that were previously and still are in good technical 

 usage. 



