10 STUDIES ON AUSTRALIAN MOLLUSCA, 



Pyrgulina perspectiva, n.sp. 

 (Plate iii., fig. 33.) 



Shell small, solid, conical. Colour white. Whorls five, besides 

 a prostrate heterostrophe apex of three turns, flattened, separated 

 by a deeply channelled suture. Sculpture : the last whorl has 

 above a series of about twenty straight oblique bars, about their 

 own breadth apart, confluent at their lower margin but not on 

 the ujjper one, both margins sinuated by the projecting ends of 

 the bars. Below these bars is a deep groove succeeded by a 

 narrow peripheral rib. On the base are a few fine spiral threads 

 intersected b}^ growth-lines. The hollows between the bars are 

 crossed Ijy fine spiral threads. The series of oblique bars ascend 

 the spire ; the bars do not correspond across the suture. 

 Periphery of the two topmost whorls slightW constricted. Base 

 somewhat hollowed. Aperture broken in the specimen studied, 

 but a prominent tooth on the columella remains. Height 2 •2, 

 breadth 1-08 mm. 



Hah. — With P. senex: one specimen. 



Type to be presented to the Australian Museum. 



From those that most resemble it, this species may be dis- 

 tinguished by the smaller size and striated interstices. 



Pykgulina senex, n.sp. 



(Plate iii., fig. 31.) 



Shell small, solid, subcylindrical. Colour white. Whorls three 

 and a half, besides an elevated, median, heterostrophe apex of 

 two turns, shouldered abruptly and separated by a deeply 

 channelled suture. Sculpture : the last whorl has above two 

 spiral keels joined at intervals by about 14 short perpendicular 

 bars, beaded at. the points of intersection and enclosing square 

 meshes. Anterior to these are six widely spaced spiral keels, 

 gradually diminishing and approximating as they recede. One 

 plain and the two ornate keels ascend the spire Delicate 

 oblique growth-lines occur in the hollows of the prominent 



