178 



industry have almost solely contributed to bring out the rare and beau- 

 tiful exhibition of fossils from the rocks surrounding his native valley. 

 Those, therefore, who desire- to contribute specimens may feel assured 

 'that in the hands of Mr. Gebhard, every fossil will be fully appreciated 

 and carefully preserved. 



BUTHOTREPHIS? CiESPETOSA, (n. species.) 

 Plate 1, fig. 1, a, b, c. 



Plant at base composed of numerous coalescing stems which in as- 

 cending are frequently bifurcated ; branches tapering to acute points. 



The mode of growth is very peculiar in this species ; in all the indi- 

 viduals seen the base appears like a coalescing or twisted bundle of 

 stems, which separate and expand above, frequently bifurcating in their 

 extension. Several specimens of this species have been found in the 

 lower part of the Trenton limestone. It is extremely different from all 

 the other species of the genus and may perhaps be referred with al- 

 most equal propriety to the genus PalceophycuSj though when better 

 known it Will probably be separated from both these genera. 



This species has been found in the vicinity of Watertown, Jefferson 

 county, and occurs in thin layers, exposed by the action of the water of 

 the river, near the lower part of the formation. 



RETEPOB\ FENESTRATA, (n. species.} 

 Plate 2, fig. 1, a, 6, c, d, e. 



Frond much expanded, loosely retioulate; branches rounded, frequent- 

 ly bifurcating, united laterally by transverse bars ; non-poriferous sur- 

 face striated ; poriferous side of branches covered with numerous small 

 angular pores, sometimes with poriferous nodes upon the poriferous 

 side of the branches ; fenestrules irregular in size and form. 



This species is very peculiar in its character, appearing at first view 

 1 ike a reticulated coral without transverse bars. The growth and bifur- 

 cation of the branches appear to have been quite irregular and they 

 approach each other so closely as often to appear as if coalescing. In 

 the presence of transverse bars, which are apparently non-poriferous, 

 uniting the branches, it differs from Eetepora, to which it is closely 

 allied in other respects. In the rounded branches and transverse non- 

 celluliferous dissepiments it resembles Polypora, but the cells are an- 

 gular as in Retepora, and the coral has the general aspect of that genus. 



Fig. 1, a, a specimen of this coral upon the surface of a fragment 

 of limestone. In some parts the coral appears to be distinctly retic- 

 ulated, while in others the branches are united by transverse bars. 



