10 THE VOYAGE OF H.M.S. CHALLENGER. 



any other part. There seems to be considerable zooecial differences between Urceoli20ova 

 nana and Urceolipora dentata, making it doubtful whether they should be placed 

 together, especially as the aperture is in the one case with a sinus, and in the other 

 without. 



Habitat. — Victoria ; New South Wales. 



Ichthyaria oculata, Busk (PI. I. fig. 4). 



Ichthyaria oculata, Busk, Zool. Chall. Exp., part xxx. p. 46, pi. xiii. fig. 7. 



The ovicell consists of two very distinct layers, and the inner one is calcareous, and 

 has an ornamentation of radiating lines, each of which is formed of what may be called 

 fine rulings. At the side of the zoarium in the lower part there is a bundle of fine 

 chitinous tubes, and from these chitinous radicals are given off. There is sometimes a 

 pore on the front, though not median, which will be a cameral pore, and the species 

 should probably be placed with Calwellia. The dividing membrane extends up to the 

 pore by the side of the aperture. 



Flustra cribriformis, Busk (PI. I. fig. 10). 



Carbasea cribriformis. Busk, Zool. Chall. Exp., part xxx. p. 58, pi. xxxiv. fig. 8. 



In a paper on some Australian Bryozoa^ I pointed out that a fine specimen in my 

 possession has no radical tubes, and in those examined from Station 186, 8 fathoms, 1 did 

 not see any, but the specimens from Station 188, 28 fathoms, have them abundantly. 

 This radical tube is very wide and annulated, giving off numerous fine tubes, and it is 

 these secondary tubes which attach themselves to the grains of sand or small shells. 

 These secondary tubes are usually simple but sometimes divide. There is a good speci- 

 men in the British Museum from an Australian locality without these radical tubes. 



Monoporella (?) capensis. Busk (PI. II. figs. 16, 17 ; PI. III. fig. 25). 



Amphiblestrum capense, Busk, Zool. Chall. Exp., part xxx. p. 67, pi. xxiii. fig. 3. 

 Monoporella capends. Waters, Quart. Joum. Geol. Soc, vol. xliii. p. 49. 



A specimen sent to me from Simon's Bay is very interesting, as it throws light upon 

 what I called strengthening plates in Membranipora spinosa, Quoy and Gaimard.' 

 These plates form lateral chambers for the opercular muscles. 



Similar chambers occur in Membranipora spinosa, Quoy and Gaimard, Membrani- 

 pora annulus, Manzoni, Membranipora cervicornis, MacGillivray, but not so marked in 

 Membranipora annulus and Membranipora cervicornis as in the other two. 



' Ann. and Mag. Nat. Hist, ser. 5, vol. xx. p. 93. 



'^ See Quart. Joum. Geol. Soc., vol. xliii. p. 48, pi. viii. fig. 32. 



