FEKNS— PECOPTEKIDB.E— PECOPTERIS. 93 



are comparable to those seen in tig. 6, pi. xliii, of tlie Atlas to the Coal 

 Flora. In this case the specimen is macerated enough to permit the satis- 

 factory discovery of the nervation over a considerable portion of its area, 

 although in the darker portions traces of the villosity are expressed on tliis, 

 the dorsal, aspect. The lowest pinnules of the fragment are slightly crenu- 

 late, representing the beginning of the transition to the pinnatifid stage 

 illustrated in Fig. 2, the further development of which is seen in Fig. 3, 

 PI. XXVI. The phase shown in Fig. 2, PL XXXIII, is the most common 

 aspect of the fragments in the collections. Specimens with pinnatifid 

 pinnules as small as those shown in fig. 7 of the plate in the Coal Flora are 

 very rare in the collection. In Fig. 4, PI. XXXIII, are shown the small 

 lateral pinnae of a villous fragment in which the course of the nerves can 

 be dimly discerned among the crowded scalelike hairs. 



Simple pinnse of the type seen in Fig. 1, PI. XXXIII, and Fig. 6 or 

 Fig. 7, are not rare in the collection. In the last figure, which is somewhat 

 suggestive of Pecopteris arborescens Brongn., the position of the immature 

 sori is indicated on the upper surface by a row of small, rather distant 

 points on either side of the midrib. 



Fertile pinnse of Pecopteris vestita are not rare in the recent collections 

 from Henry County, though I have seen none that show the details of the 

 sporangia structure. As noted in the descriptions, the groups of sporangia 

 are a little distant and well within the margin. The sporangia, which are 

 somewhat smaller than in P. p)seudovestita, are usually four to the sorus, 

 oval-lanceolate, acute, about 1 mm. long and .4 mm. wide in the lower part 

 From their deep-seated position on the lamina and the apparent absence of 

 pedicels, I am inclined to regard them as referable to the Asterotheca type. 

 A number of specimens of the form described above, identified as this species 

 by Lesquereux, are in the Lacoe collection, Nos. 3141 and 3146 being 

 among the clearest and best. Many fertile fragments labeled as this species 

 by Professor Lesquereux should be referred to Pecopteris psemlovestita, as is 

 remarked in the discussion of that species. 



Pecopteris vestita may nearly always be quite easily distinguished from 

 P. pseuclovestita by the more slender, more rigid, and muchi more tapering 

 pinnse, hardly contracted at the base; by the much more regular, parallel, 

 and decurrent pinnules, tapering more from the base upward, with apices 

 not so rounded; by the lamina, clothed on tlie upper surface with minute 



