376 The American Geolo prist. December, looi 
0.15 mm. in diameter. The riionticules are composed of groups 
of cells larger than the average interspersed with a greater 
or less number of very minute cells (mespores). The latter 
are practically confined to the regions of the monticules. 
Tangental sections reveal the charadteristic cell structures 
of the genus, with the large and small sets of acanthopores. 
Longitudinal sections show numerous diaphragms about 
one-half cell diameter apart in the large cells and much more 
numerous in the mesopores. A peculiarly characteristic thing 
is the presence of an occasional cystiphragm, especially near 
the surface. 
Observation : This species might easily be mistaken for 
Heterotrypa sub pule hella from which it differs in the two sets ' 
of acanthopores and the presence of curved diaphragms. 
Locality : Veray in the Platystrophia lynx beds. 
Amplexopora multispinosa, n. sp. 
PLATE XXXIV^ FIGS. 7 tO lO. 
Zoarium consisting of frequently branching cylindrical or 
sub-cylindrical stems of an average diameter of from 8 to 10 
mm. Surface with inconspictuous maculae. Cells of average 
size about 0.2 mm. in diameter. 
In longitudinal sections the cells are seen to be thin walled 
in the axial region and without diaphragms. They bend some- 
what abruptly toward the surface, becoming greatly thickened 
and at the same time developing in the passage from the imma- 
ture to the mature region a considerable number of diaphragms 
many of which are curved or even coalesce giving the false ap- 
pearance of cystiphragms. Near the surface, diaphragms are 
again lacking. 
In tangental sections, cutting the mature region, the cell- 
walls are thick, with very clearly defined true walls thickly in- 
terspersed with small acanthopores and covered by a copious 
deposit of secondary schlerenchyma. 
Localiqy : Associated with Callopora communis in the upperDo/- 
manella multisecta beds, at Vevay and Milton, Indiana. 
Eridotrypa vevayensis, n. sp. 
PLATE XXXV, FIGS. 7 AND 8. 
The zoarium of this species cannot be described owing to 
the fact that all the specimens seen were fragments imbedded 
in the limestone matrix. It is however of small size. 
