EEEOET ON THE POLYZOA. 
119 
This form appears to be closely allied to Retepora contortuplicata and Retepora 
cavernosa. 
(12) Retepora hirsuta, n. sp. (PL XXVI. fig. 4). 
(?) Retepora monilifera, Macgilliv., Hincks. 
Character. — Zoarium of large size, irregularly folded or crateriform, without any 
distinct peduncle. Fenestras small, oval, uniform, and fringed, as it were, with the oral 
spines or cilia. Zooecia in the older portions quite immersed ; when 
young subcylindrical, with a glistening surface. Orifice suborbicular or 
triangular, with rounded angles. Peristome raised in front and on the 
sides ; a short sublateral labial fissure, which is merged more or less 
completely into a very large round suboral pore nearly as large as the 
orifice. Usually five long clavate antenniform oral spines (often 
absent), except in the marginal zooecia. Ooecia conspicuous, with a 
trifoliate stigma. Anterior avicularia with a long delicate acuminate 
mandible (fig. 4ck) pointing transversely, and a bifid beak. Similar 
dorsal or rather fenestra! avicularia. Besides these, on every lateral 
zocecium, a minute conical avicularium (fig. 4c.) -which projects into 
the fenestra, and has a bifid beak and a sharp pointed retentive mandible. Dorsal surface 
smooth and polished, indistinctly areolated. 
Habitat. — Station 186, off Cape York, lat. 10° 30' S., long. 142° 18' E., 8 fathoms, 
coral mud. 
Mr. Hincks (Ann. Nat. Hist. May 1878, p. 360, PI. XIX. figs. 1-5), in describing 
Mr. Macgillivray’s Retepora monilifera, remarks upon the great diversities in the habit 
of growth, and the remarkable variety of avicularian appendages which it exhibits. And 
Mr. Macgillivray (Proc. Roy. Soc. Viet., part. v. p. 4), notices several forms which he 
regards as varieties ; and in my own collection I have several specimens doubtfully 
referrible to apparently the same generic type. In the Challenger Collection the only 
one referrible to this type is that above named, but to which, if any, of Mr. Hincks’ or 
Macgillivray’s supposed varieties I am quite unable to determine from the published 
descriptions or figures. To judge from Mr. Macgillivray’s figures of the chitinous parts, 
it is, however, pretty certain that Retepora hirsuta does not represent either his typical 
Retepora monilifera nor any of its varieties as there depicted. Nor in the absence of 
the evidence afforded by those parts can it be determined whether it is the Retepora 
monilifera of Mr. Hincks or either of the varieties he alludes to. The trifoliate 
fissure on the ooecium and the moniliform or antenniform oral spines are common 
to several other quite distinct forms. So far as my observation extends I believe, 
Fig. 29 . — Retepora 
hirsuta. 
