Hamillon Group. 



middle; the margins of the braucli are sharp and elevated, having 

 the appearance of two striatioiis. The midrib iias thus the appear- 

 ance of having three ridges, the central one the strongest , lateial 

 branches similar; on celluliferous side the branches are snbangular ; 

 cell-apertures minute, circular, with comparatively strong, elevated 

 marfjins; ranges of apertures separated by comparatively strong, 

 sharp carina. 



Lccalitii — Eighteen Mile creek, Erie county, X Y. 



THAMXISCUS, King. 



Thamxiscus pauciramus, n. sp 



Bifurcations distant from each other from 3 to 7 mm. : branches 

 diverging at an angle of from 30 to 40 degrees, enlarging below bifur- 

 cation; width from .50 to 1 mm.; non-celluliferous side striated, gran- 

 ulose ; cells opening obliquely, apertures small, circular, or polygonal 

 from mutual pressure ; diameter .20 mm., closely but irregularly dis- 

 posed ; usually in contact. 



XocaZiYy— Monteith's Point; Oanandaigua L^t^, N. Y, 



