136 



Fossil Polyplagophora from Eocene Beds 

 OF Muddy Creek, Mornington (Schnapper 

 Point) and Mooraboo'l, Vigtoria, ^with 

 Definitions of Nine Ne^u^ Spegies, and 

 Notes on Others. 



By Edwin Ashby and W. G. Tore, LL.D,, etc. 



[Read October 1, 1901.] 



Plate IV. 



The very valuable collection of Fossil Polyplacophora dealt 

 with in this paper has been placed in our hands for description 

 by the late Professor Ralph Tate, to whom belongs the honor of 

 having brought together such an interesting series, the major 

 part having been collected by himself and Mr. J. Dennant, of 

 Victoria, One very interesting feature of this collection is the 

 close affinity so many bear to living forms. The collection numbers 

 in all 32 valves, comprising 17 or 18 species, and representing 

 seven different genera. The whole collection is deposited in the 

 University Museum, Adelaide. 



1. Lopiea eompressa, n. sp. Pi. iv., fig. 6. 



One example of median valve. 



General Ajypearance. — Strongly carinated, side slope straight, 

 color yellowish to dark-brown. The valves are produced forward 

 in an anterior beak. 



Lateral Area. — Much raised, ornamented with five, increasing 

 to eight, at the insertion plates, granulose ridges. The granules 

 near the girdle are arranged in transverse rows. 



Pleural Area. — This area is longitudinally ribbed with 16 

 strong ridges, the interspaces are deep, the anterior portion is 

 about the same width as the ridges, the posterior portion about 

 double the width. There is a suggestion that the ridges were 

 crossed by shallow transverse ridging. 



Dorsal Area. — This area is not separated from the pleural, the 

 longitudinal ridging being continued right over the jugum. 



Measurement. — Greatest width between the slopes, 24 mm.; 

 greatest width of slopes, 11 mm.; greatest length of slope, 18 mm 

 The lon£:itudinal measurement of the dorsal area is 12 mm.; 

 divergence, 85°. The insertion plates and sutural laminae are 



