846 MR. A. W. WATERS ON 
I. hochstetteriana of MacGillivray * is clearly Hornera? fissurata, 
Busk. 
The name Jdmoneat is used in the sense it has been used for 
a long time, although recognising that im some cases it is difficult 
to ball distinctions Tatween Idmonea and Tubulipora, and that it 
is possible they may have to be merged. 
But Tubulipora spreads out continuously, whereas Jdmonee 
continues of the same width; also 7’wbuliporw has a more or less 
central ovicell with a central occiostome, while Jdmonea usually 
has the oceciostome near to the series at one side. Perhaps 
further study of the primaries and early growth, as well as the 
ovicells, may establish the position, but for the present no harm 
is doue by waiting until the whole of the group is better under- 
stood. 
Loc. New Zealand, Wanganui, ete.; Tongatabu, 18 fath. ; Hon- 
olulu, 20-40 fath.; Victoria ; Port Jackson (H.), Adelaide (4. Wy 
Sydney ; Port Stephens, 5-6 ‘fath.; Green Point, 8 fath.; Darnley 
Island, Torres Straits, 10-30 ea ; Cape Capricorn, B.M. coll. ; 
Lifu (Ph.); Port Elizabeth (in Miss Jelly’s collection). Both the 
small and the var. erecta forms from Ras Osowamembe, Zanzibar 
Channel, 10 fath. (504), and Prison Island, Zanzibar Channel, 
8 fath. (505), collected by Crossland. 
Fossil. Orakei Bay, N. Z.; Mount Gambier, S. Aust.; Bairns- 
dale, Gippsland. 
IpMONEA INTERJUNCTA MacGillivray. (PI. IT. fig. 5.) 
Idmonea interjuncta MacG. Trans. Roy. Soc. Vict. vol. xxii. 
p- 137, 10 (sep.) (1886); Waters, “ Austral. Bry.,” Ann. Mag. 
Nat. Hist. ser. 5, vol. xx. p. 256, pl. vi. fig. 29 (1887). 
Idmonea pedleyi Haswell, ‘‘ Cyclos. Polyzoa of Port Jackson,” 
Proc. Linn Soc. N.S. Wales, vol. iv. p. 351 (1880). 
Idmonea pulcherrima Kirkpatrick, ‘“‘ Hyd. and Poly. from the 
China Sea,” Ann. Mag. Nat. Hist. ser. 6, vol. v. p. 22, pl. iv 
fiz. 6 (1890). 
The zocecial aperture is about 0°12 mm., and the oceciostome is 
the same'size. 
Some specimens from Ras Osowamembe have faint ridges on 
the dorsal surface, and by the side of these ridges are rows of 
pores, transverse to the zoarium. Lines of pores, though not as 
marked, are also found on Jdmonea milneana d’Orb., a species in 
many respects similar, but milneana is a larger species having the 
zocecial aperture larger. 
Loc. Port Phillip Heads (MacG.); Green Point, Port Jackson, 
8 fath. (Waters). Ras Osowamembe, Zanzibar Channel, 10 fath. 
* “Tert. Polyzoa of ee as Trans. Roy. Soc. Vict. vol. iv. p. 120, pl. xvi. 
figs. 12-16 (1895). 
“+ See my re-deseription “ On some Oviceils of Cycl. Bry.”, Jonrn. Linn. Soe., Zool. 
vol. xx. p. 275, pl. xiv. figs. 1, 3, 4, 7 (1888). 
ose Harmer, “ Devel. of Tubulipora,” Quart. Journ. Micr. Sc. vol. xli. n.s. p. 88 
