148 THE INCLUSIONS OF THE VOLCANIC ROCKS 



In conclusion the writer desires to express his thanks to Professor David and 

 Mr. Raymond E. Priestley for unfailing kindness and assistance in the preparation of 

 this report, and to Messrs. Priestley and G. Burrows for assistance in the preparations 

 of the illustrations. 



EXPLANATION OF THE PLATES 



PLATE I 



Figure 1. — Olivine nodule, Hut Point, x N.* x 34 diams. 



Figure 2. — Anorthoclase in glass at edge of sanidinite, Mount Cis. x N. 



Figure 3. — Sanidinite in trachyte, Mount Cis ; showing eegirine-augite moulded on 



felspar. Not x N. 

 Figure 4. — iEgirine-augite in druse cavity in sanidinite, Mount Cis. Not x N. x 27 



diams. 

 Figure 5. — Microlitic ground-mass of sanidinite in Mount Cis trachyte. x N. x 37 



diams. 

 Figure 6. — Microsanidinite in trachyte, Mount Cis. x N. x 34 diams. 



PLATE II 



Figure 1. — Sanidinite in Cape Royds kenyte. x N. x 27 diams. 



Figure 2. — Sanidinite in Cape Royds kenyte showing rounded character of anortho- 

 clase and titaniferous augite on the margin. Not x N. x 14 diams. 



Figure 3. — Zoned plagioclase of microtinite in the kenyte of Tent Island, x N. x 12 

 diams. 



Figure 4. — Sanidinite from Mount Cis suggesting an aggregation of phenocrysts. 

 Hand-specimen. 



Figure 5.— An erratic from Cape Royds. Probably a partially remelted sanidinite 

 showing sanidine, leucite, magnetite, and brown glass. Not x N. x 18 diams. 



Figure 6. — Camptonitic inclusion in trachyte, Cape Bird, showing analcite and calcite 

 in an amygdule. Not x N. x 37 diams. 



PLATE III 



Figure 1. — A doleritic inclusion in trachyte, Mount Cis. x N. x 27 diams. 

 Figure 2. — A doleritic inclusion in trachyte from Mount Cis, showing augite and 



glass with idiomorphic felspars. 

 Figure 3. — A quartz pyroxene inclusion in the trachyte of Mount Cis. x N. x 18 



diams. 

 Figure 4. — A quartz xenocryst in the trachyte of Mount Cis, surrounded by a zone 



of glass with segirine needles, x N. x 37 diams. 

 Figure 5. — A sandstone inclusion with slaggy exterior in the trachyte of Mount Cis. 



Hand-specimen. 



FIC4URES IN THE TEXT 



Figure la. — Augite in camptonitic inclusion of Mount Bird trachyte, magmatically 

 resorbed with separation of magnetite and formation of a hornblende rim. Enlarged. 



Figure lb. — Ditto : Hornblende replacing augite on one side only. 



Figure 2. — Sketch of polished face of orbicular augite syenite ; erratic from near 

 Mount Cis. Enlarged. 



* x N = Xicol prisms crossed. 



