an 
BIRDSEYE LIMESTONE. 39 
Fig. 1. A fragment of rock, showing several stems of this fossil with their anastomosing branches. 
Fig. 1 a. A similar vertical section where the stems have been divided, showing that they were origin- 
ally hollow. 
Fig. 1 6. A bulb of stony matter, embraced by the stems or rootlets of this fossil. The stems apparently 
proceed from such a bulb or root, as the radicles converge below, and diverge above, as 
represented in the figure. 
Fig. 1c. A horizontal section, presenting the ends of several stems, most of which are less than the 
, ordinary size. The rock is discolored for some distance around these stems, as if deprived of 
its coloring matter by the carbonaceous character of the fossil. 
Fig. 1 d. A horizontal section of stems larger than the usual size. These stems are cellular, with apparent 
longitudinal dissepiments in two of the four presented in the figure. 
Fig. 1 e. A horizontal or transverse section of the stems, showing a concretionary arrangement of the 
calcareous matter around them, which, on weathering, presents the appearance here re- 
presented. This concretionary arrangement evidently took place during the deposition of the 
calcareous matter and the growth of the plant, and appears to have constantly formed a little 
eminence around the stem during the progress of the deposition. 
Position and locality. Throughout the Birdseye limestone, in various localities along the 
Mohawk valley ; near Amsterdam ; Fort-Plain ; St. Johnsville ; Canajoharie, &c. 
(State Collection.) 
65. 2. PHYTOPSIS CELLULOSUM (n. sp.). 
Pu. IX. Figs. 1, 1 a, 0, c, d. 
Stems subcylindrical or compressed, diverging from a centre or root, procumbent or 
ascending, branching ; branches irregularly anastomosing, forming a close strong network; 
crust or covering thin; substance cellular; cells oblong, quadrangular or stellate. 
The difference in the structure presented in these figures, appears to be due, in a great 
measure, to the direction of the section. A longitudinal section of a stem presents a simple 
fibrous structure, with more or less distant interlacing transverse fibres, forming oblong or 
quadrangular cells, as in part of 1 a, 16 and 1c. In oblique sections of the stem, square 
or rhombohedral cells are presented, as in part of 1 a ; while in others, these cells present 
a cruciform or stellate appearance, as in 1 d. Almost innumerable varieties of structure are 
presented by the surfaces of weathered specimens, where sections of stems in every possible 
direction, as well as in all stages of preservation, are presented. The form of mineralization, 
varying from calcareous through all stages to perfectly siliceous, produces also some variety 
of appearance in the fossil. The base of an individual, as fig. 1, is rarely seen, and only 
where the matter of the rock is argillaceous. The portion represented is a small part only 
of an individual; for the branching and diverging stems extend at least several feet, and 
we know not how much farther. 
While the first species appears to be the prevailing form in the Mohawk valley and some 
other parts of the State, the latter species prevails almost exclusively in the valley of the 
Black river and in Canada. The two are usually confounded, but their mode of growth and 
their internal structure are sufficient to distinguish them. When crystallized, however, and 
