458 PALAEONTOLOGY OF ILLINOIS. 



fied from the author's. Our American specimens evidently 

 prove that the scars were left by the petioles of large fronds, 

 and not of branches. This genus is thus, as Prof. Geinitz has 

 already remarked, nearly related to Caulopteris. If the name 

 of Megaphytvm should be appropriated to represent stems bear- 

 ing scars of undeveloped or adventive branches, following Gol- 

 .denberg's description of his Megaphyturn giganteum, a new 

 genus should be established for the classification of our species. 



Mega/phytvm protuherans, Sp. nov. PI. 47, fig. 1 and 2. 

 Scars convex, elevated, square-oval, slightly emargenate above, 

 marked in the upper part by vascular lines of nearly the form 

 of a reversed horse-shoe; stem irregularly striated and pointed; 

 points of various size and placed without apparent order. Fig. 

 1 represents a large specimen one-third of natural size ; fig. 2 

 two scars of natural size. It is a beautiful species found in 

 the sandstone under the upper Chester limestone at Carroll's 

 place, Pope county. 



Megajphytiim McLayi, Sp. nov. PL 48, fig. 1. Scars very 

 large, nearly contiguous, flattened, surrounded by a broad, 

 smooth margin, broadly square, somewhat rounded, separated 

 in two by a broad, irregular rib, and marked on both sides by 

 the irregular auriculate impressions of the ducts. I have seen 

 of this remarkable species another specimen similar to the one 

 figured here, and having four scars still larger than these. It 

 was found at St. John, by Mr. John McLay, to whom the spe- 

 cies is dedicated, and who fell at the battle- of Shiloh, in Ten- 

 nessee, in defending the cause of his adopted country and 

 human liberty. 



Genus Caulopteris, Lindley and Hutt. Stems tree-like, 

 bearing on the surface large, oval, peltate scars, showing the 

 point of insertion of petioles of large fronds of ferns; scars dis- 

 tant, disposed in spiral or in a quincuncial order, surrounded 

 by a broad, simple or double margin (annulus) diversely marked 

 by oval or curved above, and horn-like vascular impressions. 



