194 FLORA OP LOWKR GOAL MEASURES OF MISSOURI. 



which seems continuous with the keel of the bolster, is sometimes sliglitly 

 compressed at the point of attachment, so as to convey the idea of a small, 

 flat, triangular area somewhat like that figured, but I have not yet seen any 

 distinct cicatricial evidence connected with it. Usually, on the other hand, 

 the keel passes to the point, as seen in our figure, so that the vertical width 

 of the scar is not much greater than in Lexiidodendron lycopodioides. It 

 difi'ers from the latter, liowever, by the straight or nearly straight sides 

 forming an angle. The siirface of the shield is divided from apex to base 

 !:»}- the medial narrow keel, which is distinct, though low. The lower lateral 

 margins of the bolster are slightly raised and separated from the nearest 

 field of the next bolster by a nari'ow zone in which is occasionally seen the 

 narrow, faintly depressed line of the suture of the bolsters. 



The two halves of each shield are generally slightl)'' concave, perhaps 

 on account of the constantly raised upper end of the keel. The latter in 

 tlie decoi'ticated or abraded specimens is marked by a rounded apex, in the 

 center of which is a pore corresponding to the jiassage of the vascular 

 strand. This condition 1 find in Nos. 5461-5464 of the Lacoe collection, 

 which come fi'om the same locality and were labeled as Lepidodendron (Ber- 

 gerici) marc/inatum Presl by Professor Lesquereux. I fail to find the slightest 

 reason for separating from Lepidodendron lanceolatum either these specimens 

 or No. 5460 from the same' vicinity, which is illustrated in fig. 3 on pi. cvii of 

 the Coal Flora. Apparently the last-mentioned specimen is but the Bergeria 

 condition of the species with which we are engaged. 



All the examples labeled as the former species are older and larger 

 stems with larger bolsters. Most of the fragments referred to the latter 

 species are smaller branches and twigs. The leaves iii all the fragments 

 before me are slender and taper from near the base to an acute point. At 

 the base they are directed upward, but a little higher they are flexed out- 

 ward at a very open angle, from which they pass with a slight upward 

 turn, or often straight, to the apex. Most of them are at an angle of 70° 

 or more to the axis of the branch or twig. The central zone is frequently 

 concave on the ventral surface, while the margins are slightly turned back- 

 ward. The slender midrib usually forms a very narrow, low, round keel 

 on the dorsal surface, and meets the apex of the keel on the shield of the 

 bolster. The oblong respiratory appendages, which are occasionall}^ seen, 

 lie close to the apex of the keel and are but slightly outward inclined. 



