[Pboc. Eoy. Soc. VicTOKiA, 27 (N.S.). Pt. L, 1914]. 



Ah'I'. X. — Victorian Grwptolltes, Part IV.; Some Neiv or 

 Little-Knoivn Species. 



By T. S. HALL, M.A., D.Sc. 

 (Lecturer in Biology, in the University of Melbourne). 



(With Plates XVII. and XVIII). 



[Eead July 9th, 1914]. 



The present paper contains the descriptions of some new species, 

 as well as of some that it seems advisable of re-figure. Most of 

 the specimens are from my own collection, others were collected by 

 the officers of the Department of Mines at localities on which I 

 have reported. Two fine specimens are the property of the National 

 Museum, Melbourne, and others were found by Mr. T. S. Hart, at 

 Daylesford. 



DiDYMOGRAPTUS KXTENSUS J. Hall. (PI XVIL Fig. 1). 



For synonymy see S. L. Tornquist, Lunds Univ., Arsskrift, Bd. 

 37 (1901), Afd. 2, No. 5, p. 14; Elles and Wood, Mon. Brit. Grap. 

 Pt. 1 (1902), p. 8; Ruedemann. Giap. N. York, Pt. 1 (1904), 

 p. 668. 



The following description is drawn up from examples from Burn's 

 Reef, Ghewton : — 



Branches diverging at 180°, so that even from the beginning 

 they are in the same straight line. Width over first theca 0.5 mm. ; 

 at 3 cm. L5 nun., the increase in width being gradual and con- 

 tinuous. Thecae 10 in 1 cm., inclined at 35° to 40o. Apertural 

 angle 100° to llOo. The gradual increase in the width of the 

 branches, and their lying in one straight line, aie very charac- 

 teristic of this species. 



Horizon. — Castlemainian. 



DlDYMO(iRAPTUS HKRDITUS, 11. sp. (PI. XVIL, Fig. 2). 



Branches diverging directly at 180^, somewhat lax, and perhaps 

 somewhat reclined. Width at fir.st theca 1 niiii.. at 4 cm. 1.3 nun. 

 Thecae 7 or 8 in 1 cm., incline*! at about 'M)^. l)roadly expand- 

 ing, so that the denticles arc boldly salient. Apertui-al mai-gin 



