24 



paljEONtology of new-york. 



413. 3. RUSOPHYCUS PUDICUS ( n. *^.). 



Pl. VIII. Fig. 6 a, b. 



General form elliptical, transversely rugose or nearly smooth ; a deep longitudinal groove 

 along the centre reaching nearly to each extremity. 



This species is evidently closely allied to the preceding ones in its generic characters, though 

 it presents no elongated stem. The smaller and younger specimen is nearly smooth, while the 

 larger is distinctly rugose. There appears to be a regular gradation from P. clavatus, through 

 the present species, into the succeeding one, which is very strongly characterized. 



Position and locality. Blackstone's quarries. 



414. 4. RUSOPHYCUS BILOBATUS. 



Pl. IX. Fig. 1 a, b, c. 

 Pucoides bilobata. "Vakcxem, Geol. Report, 1842, pag. 79, fig. 1. 



Distinctly bilobate, with the lobes often separating at one extremity ; form broadly oval or 

 subquadrangvdar, very rugose transversely, ^^•ith a deep longitudinal groove running the entire 

 length. 



This species is readily recognized by its distinctly bilobate form, appearing as if composed of 

 two separate bodies joined along a central line. It is always strongly and irregularly wrinkled 

 transversely ; the two extremities being depressed, while the centre is elevated. In several 

 specimens, there arises from between the two lobes a round slender stem, which extends to the 

 length of several inches. It is impossible to say whether this stem is supported by the portion 

 described, which is the root ; or whether the stem originally supported the larger bilobate 

 portion as a floating appendage. In most cases very little evidence of the existence of tliis stem i 



is preserved ; while in others, it appears to have been an actual portion of the plant. ' 



This species is always found on the under side of the strata, attached on one side only ; so 

 that the side presented in the \ie\v is the lower side in its position in the stratum. They are 

 extremely abundant in some thin layers, but appear to have existed, like most of the other 

 species, only during a limited interv-al, and never to have extended through any considerable 

 thickness of the strata. The preceding species, which are allied to this one, are found in a lower 

 position, and never associated in the same strata with it. 



Fig. 1 a. A well marked specimen with a stipe attached. «t 



Fig. 1 J. A flattened specimen, showing the point where a stem was broken off. , ' 



Fig. 1 c. A large and well preserved specimen, showing no marks for the attachment of a stem. 



Position and locality. Gaylord and Norton's quarry near New-Hartford, Oneida county, 

 about one hundred feet above Blackstone's quarries, which is the position of the two preceding 



species. (Stale Colleetion.) 



