64 



Tlie animal has the mantle lobes free all round to the dorsal 

 line ; in life the anterior margijis of the lobes are lai-gely expanded 

 in a funnel form. The foot is somewliat disk shaped, very volumin- 

 ous, and constitutes a broad locomotory surface. 



This genus is separable from Galeonima and ScintiUa by pos- 

 sessing t^vo cardinal teeth in each valve, which are in apposition. 

 The free mantle-lobes distinguish it further from Galeomma ; the 

 animal of ScintiUa appears to be undescribed. 



The animal of both species of Epliippodonta has the creeping 

 habit of Galeomma, the valves are flexible and spread out flat 

 when the animal is in motion ; indeed, while in life the valves 

 cannot be brought to a less angle of divergence than about 70 

 degrees. 



Both species live on the mud-formed burrows of a shrimp, shel- 

 tering beneath large stones between tide-marks at Edithburg, 

 Yorke Peninsula, South Australia. 



Ephippodonta McDougalli, spec. nov. Plate xi., figs. ^a^<^b. 



Shell small, with each valve approximately semicircular in 

 outline, subequilateral, flat, yellowish-white, dull. 



Umbo inconspicuous. Surface of the valves with numerous 

 compressed slender ridges, radiating from the umbo, about 21 

 principal ones regularly disposed with one or two smaller ones 

 interposed, all bearing papillary scales ; the margin of the valves 

 with about 60 equal and equidistant square and deep crenatures. 



Dimensions. — Length of dorsal line, 10; umbo-ventral diame- 

 ter, 6 millimetres. 



Locality. — Edithburg, St. Yincent Gulf (McDongall ). 



This species differs from its congener by its inconspicuous 

 umbo, by its conspicuous radial ribs, the indented free margin 

 of the valves, and more regular outline. 



Voluta Adcocki, spec. nov. Plate xi., fig. 8. 



Shell oval-fusiform, spire moderately elongated terminated by 

 a papillary puUus ; whorls with a row of transversely elongate 

 tubercles on the periphery (about 11 to a whorl). Aperture oval- 

 elongate ; outer lip thickened internally, but bevelled off" to a 

 thin edge, not reflected ; columella Avith four oblique plaits in- 

 creasing in size from the front backwards. 



Colour yellowish-white with undulate, narrow, chestnut, trans- 

 verse lines — the depth of the plication of the colour lines being- 

 intermediate between Y. Angasi, Tate, and T"". nndidata, Lamarck ; 

 on the last whorl are two somewhat narrow chestnut spiral bands, 

 one in front of the row of nodulations and in an alignment with 

 the posterior angle of the aperture, the other about midway tO' 

 the front on the dorsal aspect. 



