110 Mr. D’Arcy W. Thompson on new ITydroid 
close to the main stem ; oblong, much elongated, about eight 
times the length of the hydrothecas, having two long divergent 
spines at the top ; orifice small, inconspicuous. 
Locality. George Town {Dr. Harvey). 
This singular and beautiful species is at once distinguished 
by the abnormal arrangement of the hydrothecae, which marks 
it out as widely separated from every other species of Sertu- 
larian with which I am acquainted. The Dynamene sertxda- 
rioides of Lamouroux (a species of which I can find no further 
mention in more recent authors) is defined by him as u D. cel- 
lulis saepe subalternisbut though somewhat approaching 
my species in this character, it differs from it entirely in many 
other points, e. g. in height, in colour, and in the absence of 
teeth on the margins of the hydrotheca} (“ bord entier; gran¬ 
deur 2 h 3 centimetres ; couleur brune ”). 
The long upright stems and short pinnae, almost perpen¬ 
dicular to the main stem, give this species a handsome and 
conspicuous appearance. 
Thuiaria, Allman. 
Thuiaria subarticulata , Coughtrey. 
Thuiaria articulata, Hutton, Trans. N.Z. Inst. vol. v. p. 258. 
Thuiaria bidens, Allman, Journ. Linn. Soc. vol. xii. p. 269. 
A few specimens of this species are contained in the collec¬ 
tion. They agree admirably with Prof. Allman’s excellent 
figure, and with the descriptions given both by him and Dr. 
Coughtrey. These descriptions differ in one single important 
point only : according to Dr. Coughtrey the pinnae are sub¬ 
alternate ; according to Dr. Allman and Captain Hutton they 
are alternate. The latter is distinctly the case in my speci¬ 
mens. Dr. Coughtrey has precedence of Prof. Allman by 
only a few months in regard to the naming of this species. 
Thuiaria dolichocarpa , Allman. 
The present collection contains a single specimen only of 
this rare and handsome species, obtained by Dr. Jolliffe at 
Hokianga, New Zealand. 
It differs in no particular, except in the slightly less con¬ 
spicuous marginal teeth, from the only other known speci¬ 
men, figured by Prof. Allman in the 1 Journal ’ of the Linnean 
Society, vol. xii. p. 270. 
My specimen was found in October 1851, probably in about 
15 fathoms water. 
