594 NEW YORK STATE MUSEUM 



and sertularians, whose structure was so much better suited 

 to preservation as to establish a presumptive hypothesis that 

 the resemblant forms must embrace the animal characters of 

 structure and would not have been preserved but for the pres- 

 ence of the latter. Still another reason is the close resemblance 

 of the impression of partially macerated algoid fragments to- 

 the markings, trails and burrows of organisms moving on or 

 in the sea bottom. A final reason, and one undoubtedly not the 

 least in importance, is the very great scarcity of specimens suf- 

 ficiently complete to show at once the form of the individual 

 while at the same time affording some hint as to its internal 

 structure. The material described below includes two of these 

 extremely rare and important examples. 



The principal specimens described in this paper are exposed 

 on a slab from the Chemung strata at East Windsor, Broome 

 co., and presented to the state museum by E. B. Hall of Wells- 

 ville N. Y. The slab is of greenish gray micaceous sandstone, 

 and is rectangular, being about 73 cm long, 32 cm wide and 1 cm 

 thick. The lower surface (with reference to its original depo- 

 sition) reveals the ferruginated remains of two or more strik- 

 ing and beautifully displayed algoid- fronds, one of which (pi. 3) 

 appears to be nearly complete. The lower end of the slab also 

 reveals portions of four segments that >may either belong 

 to a single frond or to the same tuft. Evidence of current 

 action and rapid deposition of sand is seen both in the dragging 

 of the large frond, and in the burial of the basal and lower por- 

 tions of all the fronds before the more distant segments were 

 covered by the sand. Accordingly we see the fragments in 

 another of the fronds traversing the entire thickness of the 

 slab, while the basis of the segments is not represented on this 

 slab, having been contained in the underlying rock. All the 

 segments lying at the plane of cleavage of this surface of the 

 slab show effects of current dragging in a direction slightly 

 oblique to the longer diameter of the slab. In the fine fragment 

 shown on pi. 3, the deformation is more pronounced, while in 

 both the peripheral and the thicker portions the lamina show 



