80 Mr. A. W. Waters on 
now ready, dealing with species growing. in a cupuliform 
shape, including Selenariade and Conescharellinidee, as the 
consequences of war may cause delay. 
The re-examination of some specimens of what Haswell 
described as Spherophora fossa show the import ance of this 
species in throwing light on certain fossils. The zoaria are 
small, and were described as subspherical “ with a circular 
pit at the upper pole,” but it does not seem that we must 
spvak of the pit bemg at the upper pole. The growth is 
towards the pit, a fact correctly shown by Haswell, although 
he does not allude to it (Pl. V1. fig. 1). Another form 
with zoaria about the same size, « described by Reuss* as 
Diplotaxis placentula, now changed by Gregory f to Biselen- 
uria, as the name Diplotazis was preoccupied, grows on one 
surface to the border and then turns over to the other 
vrowing towards the centre. Although the growth in the 
two forms considered is not quite identical, they partially 
explain one another. Canut{ in deseribing Biselenaria offa, 
Greg., says the zoccia radiate from a ‘ grande ancestrule,” 
which, however, is not shown in Canu’s figure, and, as the 
zocecia are Membraniporidan, it is difficult to understand. 
The importance of the pit was appreciated by Haswell, 
who did not attempt any explanation in his first paper, bu it 
in a subsequent one § he mentions a Cedlepora with minute 
Actinids lodged in cylindrical pits, excavated in the substauce 
of the polyzoarium. He thinks this may throw some hght 
on the pits of Spherophora fossa, aud described it as a case of 
symbiosis of Actimd with Ced/epora. liowever, as regards 
S. fossa, the definite position of this pit in recent species 
from various localities, as well as in fossils from many 
localities, makes this very improbable; nor is this all, for it 
is clear that what was described as “ aufrecht ee 
Zelle” or “primoidial Zelle’”’? by Reuss and others in Batopora 
and some allied genera is a similar pit, though much smaller. 
In both cases there is a raised ridge surrounding the border 
(Pl. VI. fig. 6), and there are in the pits large pores leading 
to the surrounding zoccia. Reuss, who had seen the tubes 
from these pores, ‘spoke of them as a hydrostatic system, but 
how he considered that the system functioned is not clear. 
Ci and Bassler also refer to a hydrostatic system. 
* Bry. des deutsch. Unterolig. Sitz. d. k. Akad. Wissen. Wien, lv. 
931, yl. i. figs. 5 oe (1864). 
ae «Brit, Pal. Bry.,” Trans. Zool. Soc. London, vol. xiii. p. 234 (1893). 
{<i Bry, ext.” ‘Aun, de Paléon, vol. ii. p- 80 (1907). 
§ Proc. Linn. ‘Soc..N.S. W Tales, vol. vil. p. G08 (1882), 
|| Marly Tert. Cheil. Bry. p. 73; Smithsonian Inst. U.S. Nat. Mus. 
Bull. 96 (1917). 
