Little-known Victorian Fossils. 105 



worms, likewise, often resemble the form or outline of a seaweed 

 impression. On the other hand the evidence of a vegetable origin 

 for these remains is strengthened where we have a distinct 

 •carbonaceous stain on th« rock matrix ; or as in these Victorian 

 specimens, a bleached impression, resulting from the leaching of 

 the limonite out of tlie sandy foundation immediately under the 

 impression, by the decomposition of the vegetable substance, and 

 the formation of an organic acid. And further, the nodose form 

 of parts of the outline in our fossils, as well as their irregular 

 branching habit, is strongly indicative of their plant origin. 



This species was recorded by James Hall from the Trenton 

 Limestone of Herkimer County, New York. 



Description!. — The main stem in this species of Bythotrephis 

 throws off branches and branchlets slightly decreasing in width. 

 Towards their extremities the branchlets have a crispate tendency 

 of growth. Here and there nodosities occur, usually under the 

 branches at the axils, but also along their general surface. 



A somewhat analagous species in regard to the angle which 

 the branches make with the main stem, is Brongniart's Fucoides 

 targionii', but the more flexuous and slender habit of growth of 

 the Victorian specimens renders the two forms distinct. 



Occurrence. — The present examples occur in a fine-grained 

 ferruginous sandstone containing some mica and argillaceous 

 inaterial ; the rock resembling in structure an excessively fine 

 arkose, and probably having originated from the finer portion of a 

 granitic detritus. The fossil impressions are pale in colour, or 

 almost white, in contrast to the ochre-coloured matrix, and 

 appear to have been bleached in the manner suggested above. 



Locality and Horizon. — Botanical Gardens, South Yarra. 

 Silurian. 



ANIMALIA. 



Class ACTINOZOA. 



Genus Pleurodictymn, Goldfuss, 1829. 



Pleupodictyum megastomum, Dun. (PI. XVI, Figs. 2-5). 



Pleurodictymnl sp. ind. R. Etheridge, jun., 1896, descr. Tas- 

 manian Sil. Foss., Secretary of Mines Rep., p. 31, pi. 1, fig. 1. 



1 Histoire des V^g^taux fossil es, 18'2S-36, p. 56, pi. iv., fig. 2. 



