8 PALAONTOLOaY OF NEW-YOKK. 



5. 2. PALiEOPHYCUS IRREGULARIS (n.fp.)- 

 Pi« 11. Fig. 3. 



Stems numerous, cylindrical, irregularly branched ; branches flexuous, diverging ; 

 •urfacc apparently smooth. 



This species occurs covering the entire surface of large slabs of the sandstone. It is 

 always much smaller than the preceding species ; its condition is such that no definite 

 structure can be ascertained, nor is it easy to give specific characters which will, serve to 

 distinguish it from others. 



Position and locality. This species occurs in the fucoidal layers near the base of the rock, 

 and lower in position than the last described. It occurs near Chazy, Clinton county, and 

 near Kceseville in Essex county ; also between Flint hill and Amsterdam, in the Mohawk 

 valley. 



The other species occurring in this rock differs essentially from those preceding, and 

 strictly appertains to another genus, which I propose to name 



BUTHOTREPHIS. 

 I Greek, /Su^orpSipif, produced or growing in the depths of the sea.] 



Character. Stems subcylindric or compressed, branched; branches numerous, divaricating, 

 leaflikc ; structure vesicular? 



Some species of this plant have a habit like Potamogeton (see fig. 1, pi. 21). 



6. 1. BUTHOTREPHIS ANTIQU ATA (n.sp.). 



Pl. II. Fig. 6. 



Stem somewhat thickened, subcylindric ; branches numerous, flattened, leaflike, tapering 

 towards the base and apex. 



This fossil has an appearance very similar to some of the modern sea plants, and is 

 doubtless allied to the recent Fucus ; but since the term Fucoides has been applied to 

 marine plants of such variable forms and habit, I have thought best to adopt other names 

 to designate some of the older paleeozoic species. 



In the present genus, the typical form is to be found on Plate 21, fig. 1 ; and other forms, 

 referable to the same genus, appear in the higher strata. These forms present no evidence 

 of hollow or tubular stems like the preceding, though the present species is nearly coeval 

 with those, and the two forms are again associated in the Trenton limestone. 



Position and locality. This species is found in the higher part of the Calciferous sandstone, 

 or perhaps more properly in the base of the Chazy limestone, and in a situation somewhat 

 higher than either of the preceding species. A single specimen only has been found at 

 Chazy in Clinton county. (state Collection.) 



