38 PALZONTOLOGY OF NEW-YORK. 
Genus PHYTOPSIS. 
[Greek, gurov, a plant, and ois, resemblance.] 
Stems cylindrical or subcylindrical, straight or flexuous, erect or procumbent, branched ; 
branches diverging and anastomosing ; structure cellular, consisting of thin lamine with 
transverse divisions ; other portions presenting a reticulated structure. 
64. 1. PHYTOPSIS TUBULOSUM (an. sp.). 
Pu. VIII. Figs. 1, a, 6, ¢, d, e. 
Fucoides demissus. Emmons, Geol. Report, pp. 109, 110, 383 & 384.* 
Stems subcylindrical, sometimes obtusely angular or compressed, branched ; branches 
inosculating obliquely, or in an ascending direction ; external covering thin, calcareous? ; 
centre usually filled with softer materials, or crystallized. 
This very remarkable fossil forms one of the most prominent features of the Birdseye 
limestone along the Mohawk valley. In vertical sections of the strata, it presents the 
appearance represented in figs. 1 and 1 a. Where the rock is not too crystalline, the internal 
substance of the fossil is argillaceous, and presents a contrast in color to the surrounding 
rock. The general direction of the stems is vertical ; but the anastomosing branches diverge 
at all angles, uniting with the contiguous stems, thus forming a connection throughout the 
mass for many feet in extent. 
Sometimes these tubes are filled with crystalline calcareous matter, and the surface of 
the rock presents numerous crystalline points or round spots, and, in a vertical section, 
lines of this crystalline matter, the structure of the fossil having been obliterated. This is 
true in many parts of the Mohawk valley, and in the Black river valley, where the other 
species prevails. In Kentucky and Tennessee, this rock is marked by numerous crystalline 
points and lines indicating the existence of this fossil, but I have never been able to detect 
its structure in any specimens from these places. The species is known to us in its greatest 
perfection along the Mohawk valley. 
The figures on Plate VIII. present the usual aspect under which this fossil appears. 
* This fossil has usually been referred to the Fucoides demissus of Conran ; but I regard it as by no means certain 
that Mr. C. intended to apply this name to the fossil under consideration. In his report of 1838, he enumerated no 
less than six new species of Fucorpes in the lower strata, and it is therefore safer to describe under a new name, than 
tisk confounding with other species. 
Dr. Emmons has given illustrations of this fossil in his Report above quoted. Those on page 109 correspond with a 
very common appearance of this fossil and the succeeding species (Pl. ix.). I have not been able to discover specimens 
showing the anastomosing of the connecting branches, as represented on page 110 of that report. The specimen figured 
on page 384, fig. 3 (Emmons, G'eol. Report), showing the structure of a coralline, doubtless arises from a Favosites 
or Chetetes, which has fixed its residence upon one of these stems ; for it is unlike any structure I have been able to 
detect, in the examination of several hundred specimens of the fossil in all stages of decay and exposure. 
