Tertian/.'] PALEONTOLOGY OF VICTORIA. IMolIusca. 



This very beautiful species most nearly resembles the living 

 H. ovina of North Australia and the Philippines, which has a 

 nearly similar arrangement of radiating rounded ridges, stopping 

 short of the tubular openings ; l)ut the fossil is easily distinguished 

 by the strong spiral sulcation and the greater proportion of the 

 diameter which is occupied by the spire. It is nearly related to 

 the H. Flemw f^fotiensis^ from which it is easily distinguished by 

 its comparatively regular, prominent, strong, straight, rounded, 

 radiating ridges, and the rather larger spire. 



Abundant in the Upper Miocene yellow and pink limestone of 

 (T'" 4) east bank of Moorabool River, near Maude. 



Explanation of FicnKES. 



Plate XXV. — Fiff. 2, average specimen, natural size, view from above. Fig. 2a, side view 

 of same specimen. Fig. •2b, tubular apertures, radiating ridges, and spiral sulci, magnified. 



Plate XXV., Figs. 3-3*. 

 HALIOTIS MOORABOOLENSIS (McCoy). 



Description. — Broad, ovate, depressed, preatly and even]}' convex ; spire close 

 <o posterior eilp-e, smnll, of 1-i turns, not raised above the "eneial siutiice ; apertuies 

 small, oval, numerous, about tlieir own Ienf;tli apart, a iiearlj' concave vertical space 

 intervenes between tliem and the left margin: entire surface covered with coarse sub- 

 equal slightly irregular ridges, separated by narrower sulci, and crossed by lines of 

 growth. Length of average specimen, 4§ inches ; in proportion thereto, diameter 

 of spire from posterior edge, -f^^ ; greatest width, ^^/^ ; depth, -f^-^ ; about 5 sulci in 

 5 an inch near margin. 



In form this most nearly resembles the recent H. Craclicrodi 

 of California, but is much more coarsely and distinctly ribbed or 

 sulcated, and has the very small close numerous apertures of the 

 living H. Californiensis ; it is also allied to the living H. splendens 

 of California, but has smaller apertures, is more depressed, and has 

 smaller sulci. Two living Australian species, the H. scnhricnsta 

 and H. Roei, approach most nearly in sulcation, but are distinguished 

 by theii" far larger sj^ires. 



[ 25 ] D 



