206 Mr, R. Etheridge and Dr. H. A. Nicholson 
embryos, which would prevent any spermatozoa finding their 
way up from the vulva. ‘This and the fact that the embryos 
in an oviduct are always (at least in my experience) in dif- 
ferent states of development, convince me that the organs in 
question are testes, and not receptacula seminis, which is also 
contradicted by their cellular structure. The oviduct proceeds 
from the posterior end of the ovary, and not from the anterior 
end as shown in Mr. Moseley’s figure. It also lies above the 
intestine, and not below it. 
My observations of the development of this animal are not 
yet sufficiently extended for publication ; but up to the present 
I have seen nothing to make me alter my views or accept those 
of Mr. Moseley. 
Dunedin, Dec. 16, 1877. 

XXVI.—On the Genus Paleeacis, and the Species occurring tn 
British Carboniferous Rocks. By R. Erueripcs, jun., 
F.G.S., and H. ALLEyNe Nicuorson, M.D., D.Sc., &e. 
[Plate XII.] 
1. History of the Genus and Species. 
In 1836 the late Prof. Phillips, F.R.S., described a peculiar 
and anomalous coral, to which he gave the name of Hydno- 
pora ? cyclostoma* ; but, beyond the few words which form his 
diagnosis, he offered no remarks. It is needless to say that 
the coral in question has no affinity with the genus Hydno- 
pora, a fact which Phillips himself appears in some degree 
to have surmised. Following in the footsteps of Phillips, 
M‘Coy, in 1844, described his Astreopora antiqguat, and 
pointed out its close relationship with Hydnopora? cyclostoma, 
Phill.; indeed he considered the two might be congeneric, 
although specifically distinct, and he further indicated that 
the name Astrwopora was more appropriate than Hydnopora. 
The same author in 1849, in a paper, ‘‘On some new Genera 
and Species of Paleozoic Corals and Foraminifera’, gave 
Hook Point as the locality of his species. 
Messrs. Milne-Edwards and Jules Haime, in their magni- 
ficent work ‘ Polypiers Fossiles des Terrains Paléozoiques,’ 
refer H.? cyclostoma, Phill., and Astraopora antiqua, M‘Coy, 
with some doubt, to their genus Propora §, with the remark 
* Geol. Yorkshire, ii. p. 202, pl. 2. figs. 9 and 10. 
+ Synop. Carb. Foss. Ireland, p. 191, pl. 26. fig. 9. 
} ‘Annals,’ 2nd ser. vol. iii. p. 183. § Pp. 224, 225. 
