500 note on the origin of 



Appendix. 



Since reading the above paper, with the exception of one or 

 two references which have been subsequently added, the author 

 has succeeded in preparing a good microscopic section of the 

 kerosene shale from Joadja Creek. Examined under the micro- 

 scope by transmitted light, the small spherical resinous-like 

 bodies, of which the shale is chiefly composed, are seen to possess 

 a decided organic structure, which appears to resemble that of 

 the minute " pin-head " bodies of the carbonaceous clay shales at 

 Hill Top, near Mittagong, and at Woodford in the Blue Moun- 

 tains, but differs somewhat from that of the objects figured in 

 the accompanying plate. Numerous aggregations of minute 

 spindle-shaped or club-shaped bodies are seen to occur in each 

 globule, and recall the appearance of zoospores in some forms of 

 Algse. It is just possible, therefore, that hereafter it may be 

 found that these spherical bodies are to be referred to some 

 variety of fresh- water Alga, which, like the Volvocinece, consist 

 of single gelatinous globules enclosing zoospores. In this case 

 the lenticular deposits of kerosene shale would have their ana- 

 logues in the deposits of "vegetable turtle fat" already referred 

 to, and to accumulations of infusorial earth, and perhaps to the 

 sheets of Coorongite, if the latter be of cryptogamic origin. At 

 all events, in the present state of our knowledge, it may be 

 asserted that kerosene shale was probably formed in lakeS; and 

 that it was formed from minute plant bod'es, probably either 

 sporangia or algae. Mr. R. Etheridge, junr,, has kindly promised 

 to assist the author in investigating this question, and the author 

 hopes that Mr. Etheridge and he will soon be able to communi- 

 cate to the Society a joint paper on this subject. 



EXPLANATION OF PLATE. 



The circular bodies are pseudomorphs in limonite after sporocarps (?), and 

 occur in yellowish-brown fireclay associated with the Fireclay Seam, 

 which overlies the Cannel Coal Seam at the Homeville Colliery, near 

 West Maitland. These sporocarps (?) average about one-fortieth of an 

 inch in diameter. 



