106 



V. pseudoUrata ; but the shell differs from them in being devoid 

 of longitudinal costas and by the development of the spiral striae 

 alluded to. 



Dimensions. — Length 42 mm. ; breadth 1 7 mm. Professor Tate 

 describes a specimen 62 mm. in length. 



Form, and Loc. — Eocene : Muddy Creek, Victoria. 



G. 4255. An example of the neanic stage of growth. 



Presented hy John Dennant, Esq^. 



Voluta (Aulica) macdonaldi, Tate. 



1888. Voluta macdonaldi, Tate, Trans. Eoy. Soc. South Aust. vol. x. p. 176, 



pi. xii. fig. 11. 



1889. Voluta macdonaldi, Tate, id. vol. xi. p. 123, pi. iii. fig. 5. 



The only specimen in the Museum is a very young example in 

 which many interesting characters are not brought out, though the 

 unique larval shell is well preserved. The following abstract of 

 Professor Tate's description may therefore be given : — " "Whorls 

 three, excluding pullus; the two posterior whorls angulated in the 

 posterior third, the front parallel with the axis and costated, the 

 posterior area concavely sloping upwards; the costae terminate at 

 the shoulder in high- vaulted spinous scales ; on the first spire- 

 whorl the spines are about twenty in number, and terminate each 

 a pair of costse. The body-whorl is somewhat ventricose, with 

 a high shoulder, concavely sloping upwards to the suture ; the 

 angulation crowned with sixteen spinous scales, which terminate 

 broad undulations, not ribs, rapidly becoming obsolete. Columella 

 with four distant plaits . . . whole surface [of shell] is sculptured 

 with striae and growth-lines ; the only spiral sculpture is confined 

 to the last whorl of the pullus. The pullus is not sharply separated 

 from the ordinary spire-whorls, as there is a gradual change in 

 the shape and ornament of the whorls ; the actual junction being 

 somewhat indicated by a slight eccentricity of the first spire- 

 whorls." 



The depression of the initial portion of the protoconch is not 

 a point of much systematic value, and the species is here included 

 in Aulica, though it is by no means a typical example of that 

 subgenus, on account of the general agreement of the earlier patt 

 of the larval shell with certain forms of Aulica. The first three 



