560 THE AMERICAN MIDLAND NATURALIST 



from lepidocarp cones in the Lower Silesian coal field is just as striking. 9 



This striking agreement is by no means limited to the seed megaspores but 

 continues in remarkable detail to all other portions of the lepidocarp sporo- 

 phylls and is perhaps best illustrated by comparison with a larger species of 

 Lepido car port (as yet undescribed) represented by numerous examples in the 

 Illinois Survey collections from near Wyoming Hill (Muscatine County) 

 Iowa. The latter specimens are compressed in a dark fissile shale and thus 

 entirely agree with Bassler's in mode of preservation, even showing similar 

 lengthwise folding of the sporophyll laminae. Where the shale is intact these 

 sporophylls contain well preserved lepidocarp seed megaspores. On mild macer- 

 ative treatment the fibrous megaspores of cystosporean type are easily isolated; 

 they show the characteristic trilete commissure at the apex and are associated 

 with abortive tetrad members. The "plate" Bassler described is represented in 

 these specimens (just as it is shown in his illustrations of Cantheliophorus) by 

 a very definite micropylar crest which is similar to that unmistakably shown in 

 Ltpidocarpon mazonense. The coaly and external integumentary impression 

 surfaces of Wyoming Hill shale specimens agree absolutely with Bassler's 

 figures and characterization (op. at., p. 79) as "usually granulose to the 

 unaided eye and minutely rugulose-bullate under the lens." Observation under 

 the Greenough microscope shows the surface rugosity is due to the type of 

 sclerotic cells present on integumentary surfaces. Lepidocarpon corticosum 

 (Lesq.) although preserved a little differently also is similar to Bassler's 

 material in many respects. 



Such precise agreement and the absence of any conflict in generic characters 

 indicate that species of Cantheliophorus Bassler must be referred to the older 

 genus Lepidocarpon Scott, and this has been proposed in an earlier publication 

 by the writer (Schopf, in Janssen, 1940). The geologic time range of Canthe- 

 liophorus species is entirely that of Lepidocarpon, and there is no reason for 

 concluding that Cantheliophorus is in any biological way distinct or distinguish- 

 able from Scott's genus. 



Darrah (1941, p. 89) recently has stated, that "a number of sporophylls 

 of the Cantheliophorus type . . . bear many megaspores of the familiar 'Tri- 

 letes' type" and on this account he does not accept the synonymic reference of 

 Cantheliophorus to Lepidocarpon. It is difficult to understand how any sporo- 

 phyll bearing numerous Triletes-type megaspores can justifiably be assigned to 

 Cantheliophorus or to Lepidocarpon. Bassler found none in the examination 

 of a large suite of specimens, and in failing to definitely recognize spores of 

 any sort, concluded (op. cit., p. 81) that the plants probably were homospor- 

 ous. It would seem that no matter what apparent similarities there may be 

 between the superficial form of the sporophylls, no free-sporing plant can be 

 assigned to Lepidocarpon (or to Cantheliophorus which is in complete synony- 



9 Bochenski assigned these specimens to Lepidostrobus and compared the spores with 

 Trileles giganteus Zerndt and Sporites varius Wicher, but his specimens also must be 

 identified with Lepidocarpon. There is a great difference between the spores he isolated 

 from these specimens and the free-sporing Trileles and Sporites genotypes, and lepido- 

 carp megaspores now may best be compared with Cystosporites, a genus which, in part, 

 was proposed for reception of Zerndt's and Wicher's species. 



