BY A. B. WALKOM. 701 



Ohs. — This species is most closely allied to F. cjotlandica 

 (Lam.), described from Tamworth by R. Etheridge, Junr.* 

 There are, however, differences in several of the specific 

 characters — the corallite tubes are generally larger, the 

 tabulae are more closely spaced than in F. goflandica, the 

 septa are more regularly arranged and shorter, and the mural 

 pores are generally in three vertical rows. 



Most of the corallite tubes are filled with fine, granular 

 calcite, and sometimes partly with fine, crystalline quartz- 

 grains. On account of the type of filling, internal structures 

 ore seen much better in weathered specimens than in thin 

 sections. 



Locality and Horizon. — Silurian beds of Derrengullen 

 Creek, near Yass. 



Two other species of Favosites, viz., F. gotlandica Lam., 

 and F. basaltica Goldfuss. var. salehrosa are found in the 

 same beds. 



I have to thank Mr. W. S. Dun for much advice and help 

 in connection with the preparation of this note. 



EXPLANATION OF PLATES XXX.-XXXL 



Plate XXX. 



Fig. L — Two specimens of F. tiipora{ x f ). 



Figr.2. — Part of weathered surface showing disposition of septal spines and 



shape of corallites { x 3). 

 Fig. 3. — Transverse section, showing occasional spiiiose septa ( x 10). 



Plate xxxi. 



Fig. 1.— Longitudinal section of corallites, showing bending down of 



tabulae, short spinose septa, and thickening of walls ( x 10). 

 Fiu.2— Enlargement of walls showing disposition of mural pores ( x 2^). 



* R. Etheridge, Jr., "The Corals of the Tamworth District." Records 

 Geol. Surv. N. S. Wales, Vol. vi., p. 151. 



