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NEW YORK STATE MUSEUM 



Bythograptus laxus comes from the Trenton limestone 

 of Platteville, Wis. The same locality has furnished a small num- 

 ber of other forms of vegetable aspect, which are also described' on 

 good ground as marine algae in the same publication. 



In a later paper 1 Professor Whitfield created a new genus 

 Palaeodictyota, for a form from the Niagaran of New York before 

 described as a graptolite (Inocaulis a n a s to m o t i c a Ringue- 

 berg) believing the same to be a marine alga. The present writer 

 has lately [N. Y. State Mus. Mem. 11. 1908. p. 20] shown that 

 Palacodictyota has the tubular composition and the cell apertures of 

 a graptolite of the order Dendroidea. 



These facts serve to show that there is a group of graptolites 

 that in their habitus approach so much that of the seaweeds that 

 since the time when Goeppert referred Dictyoncma to the fucoids 

 announcing the discovery of a fructification (cystocarp) like that 

 of Callithamnion on its branches, botanists have still thought it 

 possible they might be plant remains, and Dictyoncma is still cited 

 in the great standard systematic work, Engler-Prantl's " Die natiir- 

 lichen Pflanzenfamilien " [r Teil, 2. Abt. 1897. p. 554] among the 

 doubtful seaweeds. 



While searching for graptolites in the Trenton limestone of 

 Glens Falls, N. Y., the writer has discovered a congeries of 

 like character with that from the Trenton group of Platteville, 

 Wis. It is rather with the intention of recording the occurrence 

 of this rare group of fossils in the eastern Trenton than for the 

 purpose of discussing the problem of the vegetable or animal 

 character of these fossils that this note is published. We also 

 insert for this reason a form from Glens Falls that gives fair 

 evidence of being a graptolite of the order Dendroidea but has also 

 a vegetable appearance and is associated with the others, and we 

 desire to state in this connection our belief that the evidence in 

 every single case has to be weighed separately'. 



The small assemblage of Trenton fossils at Glens Falls was 

 found in thin patchy seams of very fine grained black shale inter- 

 calated in the shaly limestone forming the hanging wall of the 

 abandoned " Black marble " quarries on the south side of the Hud- 

 son river. The layer containing the fossils is about 16 feet above 

 the base of the Trenton. 



Besides the algal remains the bed has been found during this 

 investigation to contain also small fragments of true graptolites of 



'Bull. Am. Mus. Nat. Hist. 16, art. 36, p. 399 (1902). 



