Dictyonema crassibasale Gurley
Dictyonema crassibasale Gurley,
sometimes attaining a great size
0.5 m!), usually, however, of more
moderate dimensions, is the most
common species of
Dictyonema in the
chert-dolomite series at Hamilton,

   To the right is the specimen (ca. 32
cm in diameter) originated from the
Hamilton, Ontario, Lockport limestone
(Silurian), illustrated by
Ruedemann (1947).
   Ruedemann (1925) recorded this
beautiful form also from the Gasport
lens of the  Lockport limestone in which
two portions of broadly cyathiform
rhabdosome overlap in such a way as
to suggest that the rhabdosome hay
have grown upward in a flat spiral
(Ruedemann 1926).

The New York State Museum has a
perfect specimen of this species with a
diameter of 10 inches.



Ruedemann, R. 1947. Graptolites of
North America. - Geol. Soc. Amer.,
Mem. 19, 1-652, pl. 1-92.