311 
Pauline collar-like narrowing. This projection has been found in 
A. Ti lesi, A. melo, A. costata, A. juniperus, A. filkula, A. coei, 
(PI. IV, fig. 22), A. gracilis and in those forms which Kirchen- 
pauer has designated as A. abietina, var. minor, A, abietina, var. 
purpurea and A. filicula, var. tornata. 
In A. Traski the diaphragm is on each side provided witli a 
triangular, pointed, ascending portion. 
Thujaria salicornia Allman, x ) which, as far as I know, has 
not been mentioned since it was described, is identical witli SerL 
fusca Johnst., and the reason why this faet has not been earlier 
detected is, no doubt, that the hydrothecae look very different, in 
the figures given by Hincks and in those given by Allman. 
The pinna figured by Hincks is namely seen from one of the 
broad sides, while the two pinnae figured by Allman are seen 
from one of the narrow sides. 
Bioch regards Diphasia pulchra Nutt. as a synonym to 
Thuj. thujarioides (Clark), and the two forms, which have quite 
similar gonothecae, are no doubt nearly related, but a comparison 
between specimens of both has led me to the result, that they must 
be regarded as distinet species. I shall liere only point out that 
in A. pulchra the very short free distal portion of the hydrothecae, 
which is provided with an adeauline collar-like narrowing, is only 
b} a vei^ nanow interspace divided from the adjacent portion of 
the branch, while in A. thujarioides the mueh longer distal portion 
has no narrowing and is divided from the stem by a rather broad 
and deep sinus. 
The abeauline wall of Diph. digitalis (Busk) presents a feebly 
developed membranons collar, and, therefore, the aperture is pro- 
vided with two feeble lateral teeth. 
Sertularella (Cray) Hincks. 
The aperture is provided with 3—4 marginal teeth, between 
which aie found as many curves. In each curve is fixed an oper- 
culai membrane provided with a large free, valvular portion. 
>) 1, P- 
