BY W. N. BENSON. 623 



Fig.3. — Magnetite-keratophyre with secondarily introduced magnetite 



(1148); xl3. 

 Fig.4. — Magnetite-keratophyre-breccia with inclusions of dolerite (1122); 



xl3. 

 Fig.5. — Breccia of various types of keratophyre, dolerite, spilite, and 



chert (1355); x 13. 



Plate liii. 



Fig. 6. — Similar to Plate Hi., fig.5, but with large grains of quartz (1163); 

 xl7. 



Fig. 7. — Crystals of felspar and fragments of microcryptocrystalline kera- 

 tophyre in radiolarian mudstone(N.S. W.G.S. 627); x 17. 



Fig. 8. — Intrusion of felspathic tuflfinto radiolarian mudstone. The clear, 

 colourless casts of radiolaria can be seen in abundance (N.S. W. Geol. 

 Survey, 1190); x2. 



Fig. 9. — Felspathic tuff of the same character as that in Fig. 8; x 16 

 (approx.). Polarised light. 



Fig. 10, — Intrusion of breccia into banded tuffaceous mudstone; one-half 

 natural size. See Text-fig. 5. 



Corrigenda to Part iv. (this Volume), pp. 121-170. 



Page 127.— /or " Text-fig. 1. Spilite intrusive into radolarian clay." re«rf, 



*' Spilite intermingled with chert." 

 Page 143, line 12.— /or "fig.3", read '* fig.4". 

 Page 160, lines 17-18.— /or "From the nature of the case", read "For 



topographical reasons (see Map (1), Plate xxii.)" 



Postscript {added October 2Sth, 1915). — M. Giraud's descrip- 

 tion of the peperites, (basaltic tuff-breccias) of the Auvergne, has 

 come under the writer's notice while the above was in the press 

 (Bull, des Services de la Carte Geologique de la France, No. 87, 

 1902, pp. 299-367). The author reviews an extensive literature, 

 and concurs with M. Michel Levy in considering that the peperites 

 are instrusive into the Oligocene marls in the Limagne. They form 

 selvedges to basalt-dykes, developed where the dykes traverse weak 

 structures, such as marls, but not wTiere they invade strong struc- 

 tures, such as granite or limestone. Contact-effects are visible 

 above as well as below the peperites. Where the overlying strata 

 are sufficiently thin, the peperites broke through to the surface, 

 and were deposited in water; such sedimentary peperites contain 



