ON RECENT POLYZOA. 597 
7. Hornera foliacea, Maegil., op. cit. pl. xiii. figs. 1, 2; pl. xix. 
= Retihorneri, id., Busk, op. cit. 
Geogr. Distrib.: South Australia. 
8. 5 robusta, Macgil. Australia. 
Since the early—and now classical—labours of Mr. Busk on this 
peculiar genus, much has been added to our knowledge respecting species 
of the genus, but rather by way of suggestion as to its classificatory 
position. In the ‘Crag Polyzoa,’ 1859, Hornera takes its place as the 
first genus in the Idmoneide of Busk. In his descriptions (p. 95) Mr. 
Busk speaks of both recent ramose and fenestrate species. 
Ramose 1. Hornera frondiculata, Lamz. 
2. 5 borealis (MS.), Busk. 
3. 1g tridactylites (MS.), Busk. 
” 
” 
The first a Mediterranean form; the second collected on the coast of 
Norway by Mr. McAndrew; and the third by Mr. Darwin on the shores 
of Patagonia and Tierra del Fuego, and by Mr. Macgillivray in the 
Australian seas. 
Of the fenestrate kinds Mr. Busk at that time was acquainted with 
-two forms—‘ apparently distinct species, both of which I believe to be, 
and one certainly is, Australian. No account of this species, of which 
very perfect specimeus were brought by Mr. Gould from South Australia, 
has yet been published, although figures of it have been prepared. I 
propose to call it Hornera Gouldiana’ (Busk, ‘Crag Polyzoa, p. 95). 
The Hornera borealis of above is the H. lichenoides, Linn., of the Cyclo- 
stomata (‘ Brit. Mus. Cat.’ p. 17). 
In the ‘ British Marine Polyzoa’ Mr. Hincks established the family 
Horneridz for the reception of the two British species already given, 
remarking that that ‘ Hornera is connected with the Tubuliporide through 
Idmonea, to which it bears in many points a very close resemblance. It 
embraces two very characteristic groups, one of which may be repre- 
sented by H. lichenoides, in which the zocecia are covered in front by a 
calcareous crust, which takes the form of wavy longitudinal ridges,’ and H, 
violacea, in which the superficial crust is wanting (op. cit. pp. 469, 470). 
In remarking on the fossil species of Macgillivray’s Hornera folicea 
Mr. Waters (‘ Quart. Jour. Geol. Soc.’ p. 688, vol. xl.) draws attention to 
the ‘ transverse tubules’ of the species, but his remarks on his sections 
are too brief for special work. After examining some very fine speci- 
mens of the Australian Hornera both in the bulk and in section, I may 
be allowed to say that for other purposes than for the mere description 
or diagnosis of recent forms these Australian species may be con- 
-veniently studied, more especially so if only to dispel the idea of the 
supposed identity of species of Fenestella or Polypora with recent Hornera. 
The structure is most peculiar and interesting, whether we select for 
illustration the superficial features only or the tubular cells with their 
intervening tubules, as referred to by Mr. Waters. 
Family IV. Lichenoporide, Smitt. 
Hincks, ‘ Brit. Mar. Polyzoa,’ p. 471 
= Discoporellide, Busk, op. cit. p. 30. 
Lichenoporide, Vine, ‘ Fifth Brit. Assoc. Rep. Foss. Polyzoa’ for special 
details and fossil species. 
