PLKUROTOMA. 41 



Pleurotoma consutilis, Teiiison-"WoocTs. 



1880. Pleurotoma consutilis, Tenison-Woods, Proc. Liun. Soc. X.S.W. 



vol. iv. p. 9, pi. ii. fig. 5. 

 1889. Pleurotoma coiisuiilis, Dennant, Trans. Roy. Soc. South Aust. vol. xi. 



p. 44. 

 1893. Pleurotoma consutilis, Tate and Dennant, id. vol. x\ii. pt. 1, p. 221. 



Protoconch composed of one and a half smooth, shining whorls, 

 the anterior portion of which is obtusely keeled medially ; this 

 keel develops into a strong feature in the brephic and neanic 

 stages, but on approaching the adult is not so clearly marked. 

 Shell small, fusiform ; whorls obliquely cancellate, the transverse 

 and longitudinal lines being regularly spaced; aperture broad, 

 outer margin much produced towards the middle, sinus broad, 

 deep, and some distance from the suture ; columella distinctly 

 twisted ; anterior canal short. 



Dimensions. — Length 1 2 mm. ; breadth 5 mm. ; length of 

 aperture 5 mm. 



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



G. 9328. Three specimens. Purchased. 



Pleurotoma subconcava, sp. nov. 



[Plate III. Figs. 2a-J.] 



Shell large, elongated; from 11 to 12 whorls; the later portion 

 of the protoconch (the only part preserved in the type specimen) 

 is distinctly longitudinally ribbed ; beyond the sinuous fracture 

 denoting the commencement of the brephic stage these costae 

 suddenly cease and give way to spiral lineations, with a prominent 

 median sulcation indicating the position of the sinus. The whorls 

 throughout the brephic and neanic stages are flat, with a deeply 

 impressed suture, but in the adult stage they become convex, and 

 have a postero-median subangulation at the periphery. Between 

 this and the suture is a well-marked concave depression. The 

 ornament consists of closely-set spiral lineations, which are nearest 

 together in the depression alluded to ; the suture is margined by 

 one or two lineations bolder than the rest. The lines of growth 

 are fairly conspicuous, producing rough, irregular corrugations here 

 and there ; these are most noticeable in the neighbourhood of the 



