42 PLEUROTOMA. 



peripheral subangulation, and on the anterior portion of the body- 

 whorl. Aperture small, being about one-third the length of the 

 whole shell, pyriform and produced in front ; outer lip thin, sinus 

 broad, arcuate, situated on the periphery; columella covered by 

 a thin deposit of shell enamel, not callous posteriorly, slightly 

 twisted in the middle ; anterior canal rather long and deep. 



Dimensions. — Length 58 mm. ; breadth 16 mm. ; length of aperture 

 with canal 23 mm. 



Form, and Loc. — Eocene : Meribee river, Victoria. 



70421. The type specimen. Purchased. 



Pleurotoma salebrosa, sp. nov. 



[Plate III. Figs. Za-d.'] 



Shell fusiform ; whorls eight in number, in the young growth 

 flat ; in the neanic and ephebic stages subangulately convex, rapidly 

 increasing in size ; protoeonch two smooth turns, globose, the 

 later turn being wider than the succeeding whorl. Ornament 

 consisting of from 13 to 14 deep, undulating sulcations on each 

 whorl of the spire, the body-whorl being sulcated throughout in 

 a similar manner ; lines of growth not very conspicuous, but the 

 surface of the shell is peculiarly, distantly corrugated, the corru- 

 gations being five in number on the penultimate whorl, and rising 

 into indistinct, broad, oblique ribs. Aperture pyriform, much 

 contracted in front ; outer lip thin, slightly sulcated within ; sinus 

 situated about half-way between the peripheral subangulation and 

 the suture, broad and shallow ; columella smooth, striated vertically, 

 but not callous, twisted in front ; anterior canal long, broad at its 

 extremity. 



This shell differs from P. stihconcava in being relatively more 

 tumid, having a larger aperture and fewer whorls ; by the oblique 

 broad, corrugated costse ; and by the position of the sinus, which in 

 this case is indicative of Surcula of authors. The protoeonch, also, 

 is widely different, as will have been noticed. 



Pimensions. — Length 33'5 mm. ; breadth 12 mm.; length of 

 aperture 17 mm. 



Form, and Loc. — Eocene : Hobson's Bay, Victoria. 



48052. The type specimen. Purchased. 



[ 



