FERNS— PEGOPTERIDExE—PECOPTERIS. 77 



appearing oblong, somewhat oblique, sessile, contiguous, and slightly connate 

 at the base, those in the middle of the secondary pinna? 35 mm. long, aver- 

 aging 'about 2 mm. in width at base, the margins generally more or less 

 reflexed so as to make them appear sharply triangular, the laminae arching 

 between the nervils, either entire or with a few rounded, usually indistinct 

 lobes; the lower basilar pinnule of each secondary pinna generally shorter 

 and lobate, sometimes appearing auriculate ; pinnules toward the top of the 

 secondary pinnas gradually becoming confluent, passing to the entire or 

 slightly lobed apex of the pinnas; pinnules of the lower secondary pinna?, 

 near the base of the frond, 5-13 mm. long, 2-4 mm. wide, pinnatifid, or per- 

 haps pinnate, the divisions being about 1.5 mm. long and 1 mm. wide, the 

 uppermost secondary pinnae with pinnules becoming united and passing 

 into primary pinnules, pinnatifid below in rounded lolies, the succeeding 

 ones erenulate, then entire; nerves usuall}' quite distinct, the median nerve 

 passing to the top, but very slightly if at .all decurrent, emitting nervils 

 at a wide angle, the lower nervils forking, the upper ones simple, those of 

 the large pinnatifid pinnules giving off other simple nervils in the lower 

 lobes. 



Although both Pecopteris clentata Brongn. and P. jiennceformis Brongn. 

 are recorded as having been found in the vicinity of Clinton, I have not 

 yet seen any specimens that seem to me referable to the latter species. On 

 the contrary, all the examples frojn Henry County, including the large one 

 shown on PI. XLV of the Coal Flora, that were labeled Pecopteris penna- 

 formis — concerning- the characters of which there is much confusion apparent 

 in the identifications in this country — seem to agree well, most of them 

 perfectly, with specimens of P. dentcda from France and England. The 

 comparison of our American with the foreign material fully confirms the 

 views expressed in the remarks on this species in mx report on the flora of 

 the outlying basins of Missouri.' 



The common and typic,al phases of the species are shown in PI. XXV, 

 Fig. 1; PI. XXVI, Fig. 3, and PI. XXVII, the details of the nervation 

 being illustrated in the enlarged photographs, PL XXIV, Figs, la, 16, or in 

 PI. XXVI, Fig. 4. A number of specimens from Pitcher's coal mine are very 

 delicate, approaching the form distinguished by some authors as Pecopteris 



' Bull. U. S. Geol. Kurv., No. 98, 1893, p. 60. 



