169 



THE SILURIAN TRILOBITES OF NEW SOUTH WALES, 



WITH REFERENCES TO THOSE OF OTHER 



PARTS OF AUSTRALIA. 



By R. Etheridge, Junr,, Paleontologist to the Australl\n 

 Museum, and Oeological Survey of N. S. Wales, and John 

 Mitchell, Public School, Narellan. 



Part IT. — The Genera Proetus and Cyphaspis. 

 (Plates vi.-vii.) 



Genus Proetus (continued). 



Since the appearance of our first paper"^ on the Silurian Trilo- 

 bites of N. S. Wales, certain disjointed pygidia, glabella, and 

 other portions of cephalic-shields have attracted attention in the 

 Australian Museum Collection. These are from the black Cave 

 Limestone, of Cave Flat, Murrumbidgee, and were collected by 

 Mr. Charles Jenkins, L.S. Although not sufficiently complete to 

 enable us to give a detailed description, or to warrant the proposal 

 of a specific name, they yet appear distinct from either of those 

 characteristic of the Bowning Series, and are of interest as showing 

 the existence of Proetus at a higher stratigraphical horizon than 

 previously surmised. 



The fossils in question consist of portions of glabellse, pygidia, 

 and a free cheek or two. On the glabella the edge of the limb is 

 very finely concentrically lined, and the surface of the glabella 

 itself minutely granular. The pygidum has a pronounced axis of 

 seven rings, each bearing a row of tubercles. The pleuro3 consist 

 of four or five coalesced segments. 



* P.L.S.N.S.W. 1892, vi. (2), pt. iii. p. 311, t. 25. 



