686 THE LAND MOLLUSCAN FAUNA OF BRITISH NEW GUINEA, 



sac, to which the retractor muscle is affixed, at the summit ; the 

 spermatheca is at its apex boot-shaped, expanding after a con- 

 striction into a second globose sac, which communicates with the 

 system by a short wide duct. 



N. divisa, Forbes, var. inclinata, Pfr. 



Jaw (pi. xl., fig. 20) smooth, wide, arched, with a deep beak-like 

 projection inferiorly. 



Radula (pi. xxxviil, fig. 3) strap-shaped, three times as long 

 as broad; formula 96 rows of 54 : 11 : 1 : 11 : 54 ; rachidian cusp 

 large, ovate, considerably overlapping its basal plate, supplied at 

 half its length with two accessory cusps ; laterals one-third larger 

 than the rachidian, inner accessory cusp lost, outer retained, outer 

 angle of the basal plate alate ; marginals unicuspidate, cusp in 

 profile shaped like a rose-thorn, slender, inclined. 



Genitalia (pi. xlii., fig. 38), penis sac large, dilated ; spermatheca 

 oval on a wide contorted duct. 



Animal exhibiting a caudal mucous pore, pedal line and tail 

 diagonally grooved. 



Microcystina sappho, Brazier. 



Jaw (pi. xxxvin., fig. 7) short, broad, flat, smooth, with a blunt 

 median inferior projection, ends smooth. 



Radula (pi. xxxvin., fig. 4) ovate, narrow, three times as long 

 as broad ; formula 96 rows of36:10:l:10:36; rachidian twice 

 as long as broad, tricuspid, median cusp slender, lanceolate, over- 

 lapping the basal plate, auxiliary cusps seated half way along the 

 reflection ; laterals larger than the rachidian, median cusp narrow, 

 sharp, considerably overlapping the basal plate, slightly inclined 

 towards the rachidian, proximal accessory cusp rudimentary, distal 

 one well developed ; the marginals follow two or three transition 

 teeth and are the shape of a scythe blade, the concave margin is 

 apparently interrupted by an acccessory cusp, which on careful 

 examination is seen to be the posterior angle of the triangular 

 base of the adjoining tooth. 



