64 



surface ornamented with longitudinal lirae and faint striae, and 

 obliquely transverse striae and wrinkles of growth. There are 

 six or seven prominent lira? on the penultimate whorl with a 

 finer one occasionally interposed between them. On the last 

 whorl the lirae in front of the periphery are less pronounced. 

 Operculum horny, concentric, with the nucleus nearer the 

 columella margin. The embryonic shells are diaphanous, pale- 

 green, carinated on the periphery of the last whorl, on the 

 posterior part of which are interstitial striae between the lirae ; 

 the base is strongly striated ; the nuclear whorls are depressed 

 faintly striated longitudinally ; there is no umbilicus. 



The animal is oviviparous, so also is P. subline ata, P. Han- 

 leyi, Melania Tatei and 31. Balonnensis, giving birth to six to- 

 eight embryos of about three millimetres diameter. 



Dimensions. — Total length, 18 ; greatest width, 18 ; height of 

 aperture, 13 ; width of aperture, 10. 



Locality. — Cooper's Creek at Innamincka, Central Australia, 

 (Mr. James McLeocW). 



The species is quite unique among Australian congeners. 



Aspergillum multangulare, spec. nov. Plate iv., figs. 4a — b. 



Disk roundly oblong, laterally sub-compressed, ventral and 

 anterior sides prolonged into two rows of longish tubes ; par- 

 ticles of coarse sand or shell are usually agglutinated to the 

 disk, or it is adherent by one valve. 



Yalves oblong, inequilateral, translucent ; umbones anterior, 

 prominent ; surface with distant concentric growth-folds, and 

 rayed with microscopic lines. 



Tube short, straight, or slightly bent, rather constricted at 

 the proximal end ; octagonal, obtuse, not keeled at the angles ; 

 transversely irregularly striate. 



Dimensions. — Disk, antero-posterior diameter, 8 ; umbo- 

 ventral, 5 ; sectional diameter, 3'5. Tube, length, 6; diameter, 

 3 millimetres. 



Locality. — Not unfrequently cast up on the sandbeach of 

 Holdfast Bay, St. Vincent Gulf. 



This species belongs to the section of the genus correspond- 

 ing with Humplireyia of Gray, which includes two other species 

 only, both Australian ; from those it differs conspicuously by 

 its small size and many- angled tube. 



Hemimactra versicolor, spec. nov. Plate iv., figs. 12a— b. 



Shell cuneiformly ovate, solid, equivalve, very inequilateral, 

 moderately convex : colour, white, yellowish, brown, purplish, 

 bluish-white ; shining, ornamented with rather fine growth 

 ridges ; umbos distinct, incurved, approximate ; anterior side 

 very short, its margin regularly rounded ; posterior side pro- 

 duced, with a narrow dorsal area limited by an ill-defined um- 



