20 



bodies from the Sardinian Cambrian rocks as Siphonema, re- 

 ferring it to the calcareous Algae ! 



The further history of Oirvanella has been admirably worked 

 out by Prof. H. A. Nicholson* and Mr. E. Wethered,t but it 

 does not bear on tlie subject now before us. 



In one of the sections of the limestone occur a number of 

 vermiform bodies represented in PL II., fig. 8, consisting of tubes 

 intertwined and crossing one another in all directions. Some are 

 seen in longitudinal section, others obliquely so, and others again 

 transversely. No absolutely clear connection can be traced 

 between the tubes and the ca\'ity of the ^Jthniophyllum or Coscin- 

 ocyatlLUS within which they are nestling. Without unduly 

 asserting these tubes to be those of Girvanella, which they very 

 closely resemble, and taking the whole circumstances into con- 

 sideration, the identity is even probable, and I do not see any 

 other solution of their structure. I have only studied them so 

 far by means of thin sections prepared for the microscope, and 

 even in this condition there are certain anomalous features difficult 

 of explanation. Chief amongst these are the large circular tubes 

 seen here and there, and which are certainly foreign to the struc- 

 ture of the original Oirvanella, but the want of organic connec- 

 tion with either of the corals described renders it in my mind 

 quite possible that the tubes may be those of Girvanella. The 

 general appearance of this organism, when magnified, closely re- 

 sembles that of E. (Siphonema) incrustans, Bornemann. ;]: 



Geological Position. 



So far as I am aware the age of the fossiliferous rocks at Kanyka 

 and the Blinman has not been investigated [The siliceous lime- 

 stones of the Flinders Range are known to overlie unconform- 

 ably the metamorphic rocks which occupy the country to the east- 

 ward bordering on the New South Wales frontier. — Ed.], or at 

 any rate published. As already pointed out, however, Mr. Otto 

 Tepper, acting on the suggestion of Prof. Tate, has classed the 

 Ardrossan limestone as Lower Silurian, a point later confirmed 

 by Prof. Tate.§ himself. Mr. Gavin Scoular, in his paper on 

 " The Geology of the Hundred of Munno Para,"|| states the age 

 of the rocks forming the Adelaide chain and Munno Para Hills 

 as Pre-Silurian. Again, Dr. Henry Woodward, when describing^ 

 the Trilobites found by Mr. Tepper, under the names of Dolicho- 



-Ihid, 1888, v., p. 22. 



j-Ibld, 1889, VI., p. 199. 



XLoc. cif., t. 2, f. 2. 



§ Jour. R. Soc. S. Austraha for 1883-8^ (1885), YII., p. 76. 



il Ibid for 1879-80 (1880), III., p. 110. 



HGeol. Mag., 1884, UL, p. 344. 



