NIAGARA GROUP. 
155 
Fig. 10 a. A fragment of a stem of the natural size. 
Fig. 10 b. A portion magnified, showing the spinulose surface and crenulated margins of the 
apertures. 
Fig. 10 c. Two small fragments showing a peculiar mode of branching. 
Position and locality. Same as the preceding. 
548. 10. TREMATOPORA SPINULOSA (». sp.). 
Pl. XL A. Fig. 11 a, b, c. 
Stems cylindrical; apertures of cells oval, more or less closely arranged, except at intervals 
where the base of the calicle is expanded and extended into a short strong spinule; internal 
structure fibrous. 
This species is easily recognized by the comparatively strong spinules, arranged at nearly 
regular intervals. 
This is probably a rare species, since few individuals have been observed, and these with a 
single exception are simple stems, showing scarcely a perceptible diminution towards the upper 
extremities. A single minute fragment is bifurcated, and the, cells somewhat widely separated 
from each other. 
Fig. 11 a. Fragment of a small cylindrical stem without branches. 
Fig. 11 b. A bifurcating branch. 
Fig. 11 c. An enlargement of the surface, showing the spinules. 
Position and locality. On the surface of the calcareous layers in the shale, and in the soft 
shale at Lockport. 
549. 11. TREMATOPORA SPARSA (n. sp.). 
Pl. XL A. Fig. 12 a - d. 
Stems cylindrical, slender, bifurcating ; cells distant from each other, opening obliquely up¬ 
wards, calicle nasiform, elongated. 
This coral usually occurs in minute fragments scattered upon the surface of the calcareous 
layers, and shows two or three rows of cells on the exposed surface, giving about five in the 
circumference. The calicles are much more prominent than in any other of the small species, 
and stand out upon the surface like minute buds. In worn specimens, however, there is little 
prominence about the apertures. 
Fig. 12 a. A bifurcating branch of this coral, scarcely worn. 
Fig. 12 b. A simple slender branch of the same species, having the surface worn. 
Fig. 12 c, d. Enlargements from the surfaces of the same. 
Position and locality. With the preceding species very abundant in the calcareous layers in 
the shale at Lockport. {State collection.) 
