""^mo"'"] PROCEh:D[NGS OF THE NATIONAL MUSEUM. 9 



fragments of molds or casts which do not show any characters iudi- 

 catiug even approximately the form of the plant to which they belong, 

 and Nathorst remarks, that to the gronp Cylindrites are referred all 

 the fossil bodies more or less regular, cylindrical, simple, or rarely 

 branched, straight or sinuous, or spirally twisted, from one-half to 2*'"^ 

 in thickness, which are supposed to belong to algiie. He considers 

 some of them as tracks or borings of some kinds of animals creeping 

 within the deposits of muddy, clayey matter or upon the surface, while 

 others are referable to sponges. Hence the genus has no precise char- 

 acters, and though I have used the name for the description of tubu- 

 lose fragments, which in my opinion belongs to marine vegetables, I 

 admit that I do not know to what kind of fucoidal plants described by 

 botanists this fossil may have distinct affinity. 



Habitat. — Portage group, in cliffs bordering Lake Erie, near Cleve- 

 land, Ohio. Collector, Eev. H. Herzer. 



Physophycus bilobatus sp. no v. 

 PI. I, Figs. 4-9. 



Frond, utricular, rounded, oblong in outline, strangled above the middle, inflated 

 on one side, couipiessed, obtusely bilobate at the other, traversed inside by a medial 

 axis emitting bundles of filaments passing toward the borders aud apparently con- 

 stituting the internal structure, sometimes exposed by erasion of the smooth cortical 

 tegument. These bodies are represented in relief upon the surface of large, smooth, 

 concretionary pebbles of soft-grained argillaceous iron ore, upon which they appear 

 superposed aud incrusted by one side without trace of roots. They are raised above 

 the surface of the pebbles from 3 to 10'"'", according to their size, being convex and 

 therefore gradually higher toward the middle, indicated sometimes by a thin vertical 

 line traced upon the surface. 



These bodies, thirty-six in number, are all irregularly disposed at va- 

 rious distances from each other upon fourteen specimens, some of them 

 bearing only one of the organisms, others a few ; eight of them, the 

 greatest number on a single specimen, being scattered upon a surface 

 of about 150 square centimeters. 



Considering their texture, as far as it can be determined by the 

 traces of curved filaments traversing from the axis to the borders, these 

 fossil remains may be compared to the vesicular or undevelo[)ed frag- 

 ment of a leaf of Physophycus marginatus Schp. Pal. Veg., Vol. i, p. 206,* 

 wliich as seen in Fig. 4, I. c, seems to be the primary utricle from the 

 development of which are derived the other leaves or forms rej)resented 

 upon the plates. Though the relation between the leaves of Physophy- 

 cus marginatus and the bodies described as Physophycus bilobatus is dis- 

 tant, I regard it as an evidence of their organized nature. And indeed 

 those fossils of peculiar forms which appear with mere trifling varia- 

 tions upon a large number of specimens can not have been produced 



* Caulerpites marginatus Lx., Trans. Amer. Philos. Soc, vol. 13, 1869, p. 314, pi. vii; 

 reproduced as Taoniinis marginatus Lx., Coal Flora, Second Geol. Survey Penn., P, 

 1880, p. 7, pi. A, figs. 1-6. 



