386 THE LAND MOLLUSCAN FAUNA OP BRITISH NEW GUINEA, 



except the columella, which is closely and shortly curled over a 

 shallow, narrow, spiral, perforation. Height 5^, major diam. 6^, 

 minor diam. 5| mm. 



Type in the Australian .Museum. Foot narrow, with pedal line 

 and oblique grooves, tail with mucous pore. The absence or ex- 

 istence of a surmounting horn could not be ascertained from spirit 

 specimens. Genitalia (PI. xxvi., fig. 24) like that of -S. attegia, 

 Benson, in possessing a dart sac. The extreme smallness of the 

 teeth of the radula (PI. xxv., fig. 21) defied exact computation. I 

 estimated their number at 160 rows of 140 : 6 : 1 : 6 : 140. 

 The rachidian is long and slender, the median cusp overlapping the 

 basal plate, two minute pairs of auxiliary cusps are located at one 

 and two-thirds respectively of its length. The laterals are sinuate 

 with a small proximal accessory cusp and two or three distal ones. 

 The marginals are almost the shape of a reversed S, the distal 

 blade beset with numerous small cusps. 



This undescribed species has for many years been represented 

 in the Museum by specimens obtained by Mr. W. W. Froggatt, 

 of the Fly River Expedition of 1885. 



My examination of this species induces me to suppose that the 

 genus Trochonanina of Mousson should be reduced to a synonym 

 of Sitala. 



Lagocheilus poirierii, Tapparone Canefri. 



This species was described doubtfully as a Gyclotus, from a soli- 

 tary example found by D'Albertis. A much larger and better 

 preserved specimen has been sent from the Purari Valley by Sir 

 William Macgregor. Its measurements are: height 11, maj. 

 diam. 10, minor diam. 9 mm. The keel and elevated lines des- 

 cribed by Ta[)parone Canefri are in this instance (PI. xxiv, fig. 2) 

 clad with short stiff epidermal bristles. The operculum (PI. xxiv, 

 fig. 4) is corneous, circular, multispiral, with subcentral nucleus. 

 The species will theiefore be more appropriately bestowed in 

 Lagocheilus. 



