MEDINAN, NIAGARAN, AND CHESTER FOSSILS 
69 
portrayed under the name ButhotrepMs gracilis, a name previously 
used by Hall in for a Clinton form of New York. In the 
second volume of the Paleontology of New York (p. 18) Hall 
corrected this error and introduced the name Buthotrephis tenuis 
for this genotype. 
In describing Buthotrephis tenuis Hall states that carbona- 
ceous film is all that remains of the fossil/^ and also that this 
fossil is found ^^upon a shaly carbonaceous film on the lime- 
stone.” 
In his original description of the genus Hall defines the latter 
as follows: Stems subcylindric or compressed, branched; branches 
numerous, divaricating, leaflike; structure vesicular? 
Little appears to be gained by a study of the Trenton type. 
In his study of two species from the Kokomo member of the 
Cayugan, at Kokomo, Indiana, however. Dr. David White makes 
some observations which may prove illuminating in connection 
with the structure of the genus Leveilleites. He describes the 
fronds of Buthotrephis divaricata White^^ as rugulose or minutely 
granulose, and marked, especially along the medial portion, 
by very delicate, irregularly, but more or less obliquely, arranged 
trichomatose or filamentose impressions. Without a cen trial 
axis or strand. Vague globular bodies near or at the apices 
of the branches. Similarly he describes the texture of Butho- 
trephis newlini White^^ as slightly rugose, marked by irregular, 
very slender, intermingled and tangled trichomatose or filamen- 
tose elements, those near the center being coarser, often thread- 
like, and more or less longitudinal in their arrangement. Simi- 
lar filamentose texture occurs in Buthotrephis lesquereuxi Grote 
and Pitt, from the Bertie member of the Cayugan at Buffalo, 
New York. Here there is an irregularly woven or cloth-like 
mesh. 
More recently, specimens referable to Buthotrephis lesquereuxi 
Hall, James, Geology of New York, part 4 (fourth district), p. 69, fig. 14. 
White, David, Two new species of Algae from the upper Silurian of Indiana: 
U. S., Nat. Mus., Proc., vol 24, pp. 265-270, pi. 16, 1902. See also Proc. Biol. Soc. 
Washington, 15, 1902, p, 86. 
Idem. p. 266, pis. 17, 18. 
