50 
VICTORIA MEMORIAL MUSEUM. BULLETIN NO. I 
where the types were collected by W. A. Johnston. The holo- 
type is No. 7839, and the paratype 7839a. 
Tetradium racemosum, sp. nov. 
Plate VI, fig. 2, 
Corallum consisting of elongate, irregular, bifurcating bundles 
of tubes which are square in section. The bundles vary from 
oval to rectangular in section, and often have a very irregular 
shape. Typically, the section shows the cells arranged four 
deep, and about 30 corallites to the bundle. The corallites in 
places vary widely from the typical square section. They seem 
to be rather thin -walled, and the septa are thin and usually 
short. Tabulae are scarce, or perhaps entirely absent. The 
corallites measure from 1 to 1*25 mm. in diameter, and, in sec- 
tion, one of the bundles is 11 mm. in greater diameter and 4*5 
mm. in lesser. 
Tetradium cellulosum 1 has never been properly described, but 
it would appear that the bundles contained fewer corallites than 
do those of the present species. The type-locality of Hall’s 
species was Watertown, New- York, and the writer has before 
him specimens from the Lowville at that locality. There seem 
to be two forms present, in both of which the bundles are smaller 
than those of Tetradium racemosum. In the larger form there 
are about 15 corallites to the bundle, and the corallites are very 
much smaller than those of T. racemosum . In the other form 
there are only 4 corallites in a bundle, and the bundles are only 
1 * 75 to 2 * 25 mm. in diameter. This same form occurs in Canada 
in the township of McNab, and a photograph of a specimen from 
that locality is introduced for comparison (Plate VI, fig. 4). 
This can hardly be the typical cellulosum , however. 
1 HaII, Palaeontology New York, Vol. I, p, 30, 1847. 
