578 AUSTRALIAN LAND PLANARIANS, 



correcting the determination given above at the earliest oppor- 

 tunity. From a careful examination of all the specimens now 

 available, I am satisfied that they belong to one species, and 

 that its affinities are with G. mediolineata rather than with G. 

 quinquelineata as I at first supposed. 



The collection sent me by Mr. Mellor may be divided into 

 three series as follows : — 



(a). Typical specimens of G. mediolineata, Dendy, (7, p. 76, 

 pi. vii., figs. 1-2, and this paper, pi. xxxiv., fig. 4), with bold 

 median line as usual and the lateral diffuse lines at anterior tip 

 running back for a short distance. 



(b). Examples of Dendy's three-lined variety of the same species 

 (loc. cit., p. 77, pi. vii., figs. 3-3a., and this paper, pi. xxxiv., tig. 5). 

 The lateral lines extend in some individuals from end to end, 

 while in others they fade out at varying distances back. 



(c). A very distinct variety having five continuous dorsal lines 

 (pi. xxxiv., fig. 6) and which constitutes the form which I propose 

 to distinguish as G. mediolineata, var. simularis, to denote its 

 resemblance to G. quinquelineata. From the latter species and 

 its var. accentuata the present variety is distinguished by having 

 the lines at unequal distances apart, the lateral lines being close 

 to the median, while the marginal lines have about twice that 

 space between them and the lateral lines, and are also about 

 same distance from the margin. The median line is always 

 strongly marked, the lateral lines are more diffuse, and the 

 marginal lines usually as strongly pigmented as the median. 

 The specimens received were of different lengths up to 140 mm. 

 when crawling. Two examples in spirit 112 and 85 mm. in 

 length have the peripharyngeal aperture 46| and 36£ mm. 

 respectively from anterior tip. In none of the specimens is the 

 genital opening visible. 



Spencer (10, pp. 86 and 93, pi. xii., fig. 15) figures a variety of 

 G. mediolineata which he considered intermediate between that 

 species and G. quinquelineata. This I formerly thought might 

 be a somewhat abnormal example of G. quinquelineata, var. accen- 

 tuata, (11, p. Ill), but in the light of present knowledge I now 



