690 THE LAND MOLLUSCAN FAUNA OF BRITISH NEW GUINEA, 



laterals with a large square-headed cusp ; after ten series a hook 

 develops on the proximal side of the main cusp, which latter 

 diminishes in size and divides into two or three cusps in the 

 extreme marginals. 



In the figure the marginal teeth should be transferred from the 

 right to the left of the central. 



G. woodlarkianus, Souverbie. 



Jaw (pi. xli., fig. 28) low, boomerang-shaped, central third 

 crossed by about half-a-dozen weak ribs with narrow interstices 

 denticulating either margin, ends smooth, rounded. 



Radula (pi. xlii., fig. 36) tongue-shaped, twice as long as broad; 

 formula 130 rows of 42 : 9 : 1 : 9 : 42 ; rachidian about two-thirds 

 the size of the immediate laterals, square-headed; laterals straight, 

 square-headed, with the alate angle of the basal plate scarcely 

 shown ; marginals trifid. 



Genitalia (pi. xli., fig. 32) closely resembling those of trobrian- 



G. trobriandensis, Hedley. 

 Jaw (pi. xxxviii., fig. 5) slightly arched, central third crossed 

 by half-a-dozen weak ribs and narrow interstices, which denticulate 

 both margins, ends smooth, obtusely angled. 



Radula (pi. xxxix., fig. 14), formula 154 rows of 55 : 8 : 1 : 8 : 55; 

 rachidian square-headed, projecting along three-fourths of the basal 

 plate, rather smaller than the laterals, which are also square-headed, 

 slightly sinuate, twice as long as broad, alate angle of basal plate 

 slightly developed ; the marginals possess in addition to the main 

 cusp a proximal falcate and a minute distal accessory cusp. 



Genitalia (pi. xlii., fig. 33), penis sac slender, much contorted ; 

 spermatheca ovoid on a long slender peduncle. 



G. boyeri, Fischer and Bernardi. 



Jaw (pi. xli., fig. 25), the central third narrow, crossed by half- 

 a-dozen weak ribs with narrow interstices, ends smooth, rounded. 



