3-4 
Journal of the 
of close opposite or sub-alternate pinme, curved towards tlie tips. 
Hydrothecae cup-shaped, tapering towards tlie base, set at an 
angle of about 50°; aperture with three slightly everted teeth on 
each side, and a slender incurved tooth in front: three or four 
minute denticles in a group at the base of the hydrotheca, and a 
similar group a little above. Mesial sarcotheca, a long slender 
tube, not tapering, rising from the pinna to double the height of 
the liydrotheca, to which it is adnate up to the margin; upper 
part curved and generally produced forwards parallel with the 
pinna; two orifices, lateral and terminal. Lateral sarcothecse 
short, ovate, pointed behind, truncate or sub-tubular in front, 
canaliculate. Cauline sarcotheca? similar to the laterals, two on 
the stem at the base of each pinna. 
Gonotheca?, borne in rows at the bases of the pinnae, smalb 
membi’anous, somewhat pyriform, truncated above. 
Colour, light brown. Ilab. Griffiths’ Point (Mr. Goldstein); 
S. Australia (Mr. Smeaton). 
I have named this species after Mr. D’Arcy W. Thompson, who 
has described a number of Sertularians from Australia and New 
Zealand. The mesial sarcothecse are rather variable in length, 
often being produced fonvards like those of the last two species. 
The gonotlieca? resemble those of A. pennatula. 
A. PROLiFERA. n. sp. Plate XIY, fig. 5. 
Stems thick, six or seven inches in height, pinnate, sometimes 
giving oft' small branches, especially near the summit; pinna3 
close, straight, ascending, alternate or sub-alternate, two on each 
internode. Hydrothccie deep, cup-shaped, tapering towards the 
base, set at an angle of about 35°; aperture with a nearly erect 
tooth in front, and three on each side, the first and second from the 
front everted; two series of minute denticles in the basal part of 
the cell. Mesial sarcotheca generally somewhat longer than the 
hydrotlieca, rising mainly from it, but continuous with the pinna 
by a small part of its base; adnate to the hydrothecre up to its 
margin, and projecting from it, tapering, with lateral and terminal 
apertures, which are sometimes united. Lateral sarcotheca? flask¬ 
shaped, adnate by their base to the hydrotlieca, with a tubular 
orifice directed downwards at right angles to it; the front margin 
