168 GASTROCOPTA, AUSTRALIA. 



localities will be required to show whether this is to be treated 

 as a distinct species, or as an eastern race or subspecies of G. 

 larapinta. 



Form having an interpolated plica, pi. 30, fig. 8. A series 

 of shells found with the specimens of G. pediculus queenslan- 

 dica and mussoni, at Calliungal, Queensland (C. T. Musson), 

 agrees in most respects with G. larapinta, having an inter- 

 palatal plica, exactly as in that form. There is usually a small 

 basal fold, sometimes lacking. The shells average smaller, 

 thinner, just perceptibly more obese than larapinta. The pari- 

 etal lamella is shorter and less curved than that of the asso- 

 ciated G. mussoni. 



Length 2.3, diam. above aperture 1.2 mm. 



In the lot from Calliungal, sent by Mr. Hedley, I find 9 

 specimens of this form, 8 mussoni, and several G. pediculus 

 queenslandica, the latter readily separable by the short, hori- 

 zontal columellar lamella. Whether the present form belongs 

 to larapinta or to mussoni I am uncertain. 



103. GASTROCOPTA LARAPINTA (Tate). PL 30, figs. 5-7, 9-11. 



"Shell dextral, oblong-elliptic, pellucid, white, narrowly 

 umbilicated. Spire cylindrical, obtuse at the apex; whorls 

 five, very convex, separated by a deep suture, ornamented by 

 very oblique striae of growth ; last whorl slightly ascending at 

 the front; aperture roundly oblong, multidentate within; 

 peristome narrowly and horizontally expanded, the margins 

 united by a thin parietal callus. The dentition of the aper- 

 ture consists of two lamelliform, contiguous plaits on the pari- 

 etal wall, the outer one of which is the larger, an equally large 

 plait on the columella, one on the basal margin, and one on 

 the outer lip. All these are approximately equidistant. In 

 addition, denticles occasionally appear, one exterior to the 

 large plait on the parietal wall, one anterior to the columella 

 plait, and one or two on the outer lip. Length 3, diameter 

 1.25 mm." (Tate). 



Central Australia. 



Pupa larapinta TATE, Report on the work of the Horn 

 Scientific Expedition to Central Australia, Pt. ii, Zoology, 

 Feb., 1896, p. 205, pi. 19, f. 19 a, b. 



