36 THE OLDEE MESOZOIC FLOEA OF VIEGIFIA. 



of the ultimate pinnae of both sterile and fertile plants, always much larger than the 

 rest, broadly spatulate in shape, deflexed along the principal rachis, and never con- 

 taining fructification. Middle nerve dissolving into branches towards its summit, 

 lateral nerves going off obliquely, the lower ores more freely branched than the upper 

 ones, which branch once or twice, lateral nerves "of the crenulated lowest pinnules 

 branching several times so as to fill the crenulations, or lobes. Nerves of the deflexed 

 heteromorphous lowest pinnules branching and diverging in a flabellate manner. 

 Fructification consisting of large, prominent globose sori, which are composed of five 

 or six sporangia arrranged radially around an axis ; sori confined usually to the lower 

 half of the pinnules, forming a row on each side of the middle nerve and placed about 

 half way between the middle nerve and the margin of the piuuules, inserted on one of 

 the branches of the lateral nerves, usually the lowest one, in pinnules with few sori, 

 the pinnules then being broader than those that are fully fructified. The latter, or 

 the fully fructified pinnules, are narrower than those which have their tips free from 

 sori, or that are partially fructified, and they have the lateral nerves reduced to a 

 single pedicel which bears the sorus. The sori are more numerous on the pinnules of 

 the lower part of the frond and on the pinnules that occur midway on the ultimate 

 pinnae and toward their ends. 



The great numbers of finely preserved and large specimens of this 

 remarkable plant that I have obtained have enabled me to make a very 

 complete study of it, and to present it in nearly, if not quite all of its numer- 

 ous forms. I have very fully illustrated it, selecting typical forms from 

 many hundreds that have passed under my eyes. I hope that the peculiar 

 features of the plant will excuse the number of figures given. • I will say 

 here that were it not for the deflexed spatulate pinnule, which is unmistak- 

 able, I would have been tempted to make several species out of this single 

 plant. This is a possible error that should always be borne in mind when 

 one has only a few specimens of a plant before him. The sterile forms 

 differ from some of the fertile forms quite enough to excuse their separation 

 as a distinct species in the absence of some such guide as the spatulate pin- 

 nule. It will be noted that this deflexed spatulate pinnule is the most obvious 

 characteristic of the plant. It resembles the similarly placed heteromor- 

 phous pinnule of Odontopteris. The only plant of the younger formations 

 that has a feature like this is the Pecopteris lobifolia of Lindley and Hutton, 

 found in the Oolite of Yorkshire, England. Our plant is of course not to 

 be identified with this, on account of the numerous obvious points of differ- 

 ence. Bunbury first described the plant now in question under the name 

 Pecopteris bullata. His specimen was evidently very imperfect, and did not 



