166 PHOS, 



of difference, and which has more weight than any other in 

 deciding the writer to suggest its separation from Phos, properly 

 so called, is the character of the protoconch. In Phos the 

 protoconch is, typically, turbinate, the turns gradually increasing 

 in size from an exceedingly small beginning ; moreover, the coils 

 are regular, their axis being in alignment with the axis of the 

 whole shell. In Loxotaphrus, on the other hand, the protoconch 

 (Plate VI. Figs. 3«-5) has fewer turns (typically one and a half), 

 and is by no means turbinate, it commences by an obtuse inflation, 

 and quite one-half of it is oblique with reference to the axis of 

 the shell. 



Type —Phos variciferus, Tate. 



Phos (Loxotaphrus) variciferus, Tate. 



1888. Phos (?) variciferus, Tate, Trans. Roy. Soc. South Aust. vol. x. p. 169, 



pi. xi. fig. 3. 

 1893. Phos variciferus, Tate and Dennant, id. toI. xvii. pt, 1, p. 219. 



Shell turriculate, narrow, bucciniform ; protoconch (Plate VI. 

 Figs. 3ff-J) composed of one and a half smooth turns, the earlier 

 portion being inflated and implanted obliquely with reference to 

 the axis of the shell, later portion finely striated longitudinally 

 and ending abruptly ; the main features of the ornament of the 

 whorls suddenly make their appearance in the brephic stage (a 

 very unusual character), and do not apj)ear to be foreshadowed 

 in the protoconch. That ornament consists of prominent, slightly 

 oblique, longitudinal costae, with smaller longitudinal lineations 

 running between and obliquely over them ; and broad, irregular, 

 spiral threads, considerably elevated on the costae, especially at the 

 angular periphery, where the points of intersection are surmounted 

 by small tubercles, complete the sculpturing of this ornate shell. 

 The phenomena of the aperture have been sufficiently described 

 under the subgeneric heading. 



Dimensions. — Length 26 mm.; breadth 11mm.; length of 

 aperture and canal 12 mm. 



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



G. 4160. An example of the gerontic stage. 



Presented hy John Dennant, Esq. 

 G. 9377 A series exhibiting stages of growth. Purchased. 



