72 
BULLETIN OF THE LABORATORIES 
I. Rhombopora multipora, sp. n. 
(Plate VII, Pig. I, a, b, c) 
Branches doubtlessly dividing; in a length of 25 mm. no such 
division has taken place, but traces in the rock about 10 mm. beyond 
seem to indicate that some method of branching has occurred. 
Branches of medium size, 1.4 mm. wide. Cells arranged in diagonal 
intersecting and in longitudinal rows; at least 7 cells are found in a 
distance of 2 mm. in the vertical rows, and about 9 cells in the 
same distance in the diagonal series. About 20 longitudinal rows sur- 
round the stem. Mature region of the cells short, strongly deflected 
laterally, but not reaching the surface at right angles to the same ; im- 
mature region much longer, departing from the centre of the branch 
at a low angle, suddenly bending into the mature portion. The vesti- 
bule in well preserved regions has sloping sides and an hexagonal oval 
outline; the ridges separating the cells are rather narrow and are cov- 
ered with low, indistinct closely arranged granules, which do not 
seem to be arranged in well defined rows, as in other species of this 
genus; in worn portions of the specimen the ridges seem broader and 
lower, and the granules are indistinct, and scattered. Towards the 
base the vestibule is more inclined, lengthening its outline; at or just 
within its border there is frequently a low, rounded node, easily over- 
looked. 
From most species of this genus this form may be readily distin- 
guished by the size of the branches and the more numerous cells. Rh. 
lepidodendroidea., Meek., has branches 1.75 to 3 mm. wide; from 5.5 to 
6.5 cells occupy the oblique rows (using a standard length of 2 mm.). 
Rh. crassa, Ulrich, has branches 2.5 to 4.5 mm. wide; from 5 to 5.6 
cells occupy the oblique rows. Rh. persimilis, Ulrich, has branches 
.88 mm. wide ; 4.4 cells occupy the vertical rows, and 8 cells the ob- 
lique rows. Rh. pidchella, Ulrich, has the same measurements as the 
last. Rh. armata, Ulrich, has branches perhaps slightly wider than 
the last two, about 5.5 cells occupy the vertical rows, and 9.5 cells the 
oblique rows. Rh. elegantula, Ulrich, has branches 2.5 mm. wide, 
from 3 to 4 cells occupy the vertical rows, and almost 5 cells the di- 
agonal rows. Rh. Wortheni, Ulrich, has branches from 1.3 to 3 mm. 
wide ; 6 cells occupy the vertical rows, and almost 9 cells the oblique 
rows. 
The nearest ally of this species in external features seems to be 
