72 Proceedings of the Royal Society of Victoria. 



was able to obtain evidence of the existence of the T. cadnceiis 

 zone with a dip to the east. From this evidence I looked for 

 and found Z. Logatii a mile to the south as above indicated. 

 L. Logani is abundant in this zone, and I have a doubtful 

 frao;ment from the zone below. 



This species has been confounded with two others from which 

 it, however, is quite distinct. In its method of branching it is 

 truly dichotomous, excepting as an abnormality, when a branch 

 is occasionally suppressed, and the branches arise at no great 

 distance from the centre. The genus with which it has been 

 confused is Gotiiograptus (McCoy), in which true dichotomy does 

 not occur, but as described by Professor McCoy,* each of the 

 four main branches is angularly bent, and from the salient angles 

 secondary branches are given off, which alone are celluliferous. 

 A branch stripped of its hydrotliecje would have the appearance 

 of Thaninograptus. Goniograptus Thureaui (McCoy), the type 

 of tlie genus, has about forty-eight branches, is rather rare, and is 

 contined to the T. fruticosus zone. Another species has from 

 twelve to sixteen branches, and is common in the same zone but 

 occurs, though i-arely, as high as the Burns' Keef beds. An 

 examination of a large number of specimens of the latter species 

 leaves no doubt in my mind that it is congeneric with G. 

 Thureaui., but specitieally distinct. Herrmanj describes and 

 figures a species as Dichograptjis Kjerulfi which has a similar 

 aspect to the pi-esent form. I have not seen the central disc he 

 describes, and the constant differences in the number, form and 

 arrangement of the hydrothecfe show that our form is distinct from 

 Herrman's. The method of branching is so striking" in McCoy's 

 genus that, in spite of Herrman's objection, I think it should stand, 

 and, moreover, that Herrman's species should rank under it. 

 The horizon he (juotes for Sweden, is Lower Phyllograptus shales, 

 just where it occurs with us, and there, as here, it is not associated 

 with L. Loga?ii. Mr. R. Etheridge, Junr.,J figures two examples 

 which he calls L. Logani, but both are evidently referable to 

 Go?iiograpius, tlie clinacters of wliich had not then been pointed 



» Proa. Pnl. Vic, Dec. V., jil. 50, also A.M.N.H., vol. xviii. (187G), p. 129. 

 t Geol. Mag. 1866, pp. 13, rf seij., tvaiisl. and abrd. by W. S. Dallas from Nyt. Mag. for 

 Naturviil, vol. xxix. 



I A.M.X.H., vol. xiv., 1874, pi. iii., figs. 11 ami 12. 



