Mr. A. W. Waters on Australian Bryozoa, 255 



a specimen from New Zealand has the opening of the ovicell 

 low down on the dorsal surface. 



Log. Patagonia ; Tierra del Fuego (?) ; New Zealand ; 

 Victoria ; La Perouse ; Botany Bay, New South Wales, 

 washed on shore. 



77. Idmonea radians (Lamk.), non Defr. 

 (PI. VI. figs. 27, 28.) 



Retepora radians, Lamk. Anim. sans Vert. ii. p. 183. 



Idmonea radians, M.-Edw. Ann. Sc. Nat. 2nd ser. vol. ix. p. 217^ pi. xii. 

 fig. 4 ; Stoliczka, Foss. Bry. der Orakei Bay, p. 116, pi. xviii. figs. 9, 10 ; 

 Busk, Oat. Mar. Pol. pt. iii. p. 11, pi. vii. figs. 1-4 ; Waters, 

 Quart. Journ. Geol. Soc. vol. xl. p. 684; MacG. Zool. Vict, 

 dec. vii. p. 30, pi. Ixviii. fig. 3 ; Haswell, Proc. Linn. Soc. New South 

 Wales, vol. iv. p. 351 ; Busk, ' Challenger ' Report, pt. ii. p. 10. 



I have already {he. cit. p. 676) referred to a structure of 

 the ovicell which seems to have been overlooked by other 

 writers, and now give a figure showing the finely perforated 

 lateral plates. The ovicells are elongated raised protuber- 

 ances, occurring at a bifurcation, divided up by irregular 

 ridges, between which are large pores deeply pitted, and on 

 each side there are usually two, but sometimes one or three, 

 plates, distinctly bordered and with numerous extremely fine 

 perforations. 



The ovicells of the Cyclostomata have nearly always the 

 surface covered with much more numerous pores than the 

 rest of the zoarium ; and it is therefore most interesting, 

 and no doubt a fact of considerable physiological importance, 

 that in some cases it is only a part of the ovicell which is 

 provided with these numerous pores. 



Log. Fossil : Mount Gambler (?) ; Orakei Bay. Living : 

 New Zealand ; Tongatabu, 18 fath. ; Honolulu, 20-40 fath. ; 

 Victoria; Port Jackson (/i.) ; Adelaide {A. W.) ; Vaucluse 

 Point ; Port Stephens, 5-6 fath. ; Green Point, 8 fath., New 

 South Wales, and Darnley Island, Torres Straits, 10-30 

 fath. (all dredged by Brazier). 



78. Idmonea Q) irregularis^ Meneghini (non Beissel). 



Idmonea im-egularis, Menegh. " Polipi della fam. del TuhuL," Accad. di 

 Sc. di Padova, vol. vi. 1844, p. 12 ; Waters, Ann. & Mag. Nat. Hist. 

 ser. 5, vol. iii. p. 270 ; Busk, Chall. Rep. p. 14 ; Haswell, Heller. 



Tervia Folini, Jullien, " Dragages du TravaiUeur," Bull. Soc. Zool. de 

 France, t. vii. p. 5, pi. xiii. figs. 8, 9. 



Specimens from Holborn Island have the oral aperture O'l 

 millim. wide. I do not consider that this can remain under 

 Idmonea. seeing that the ovicell is dorsal, occurring near a 



18* 



