28 RECORDS OF THE AUSTRALIAN MUSEUM. 



The reproductive system of this form seems to me to be 

 especially worthy of attention. Branching from the vagina, 

 opposite to the entrance of the duct of the spermatheca, is a 

 gland of unknown function, marked X in the accompanying 

 illustration (PI. v. fig. 13) ; this exactly corresponds to the gland 

 marked x in Semper's illustrations of the genitalia of falconeri 

 and ditfresni, and also to the gland marked v. p. in the figure of 

 the genitalia of cunninghami published by the author. It will 

 be observed that Semper's drawings show a short, wide, recurved 

 duct, and mine a narrow, subcylindrical one. On referring to a 

 sketch of the organs of dufres7ii, which I took some time ago, I 

 notice that the gland in question appears of the form observed 

 in cunninghami and atomata ; possibly each form may be proper 

 to different periods of gestation. No other Australian helices are 

 known to possess such an appendage, and its value as a means of 

 classification cannot be denied. The musculature, which is shared 

 by the species with which I would associate atomata, is also 

 peculiar. The retractor muscle of the penis is not attached to 

 the floor of the pulmonary cavity as in some helices, but is 

 a broad band arising from the main retractor muscle of the 

 columella. The narrow subcylindrical portion of the penis sheath 

 extending from the insertion of the retractor muscle to the origin 

 of the vas deferens, is also strictly analogous to the similar 

 portions of cunninghami, falconeri and dufresni. The ovo-testis 

 is a compact, yellow, bi-lobed body, not ramifying through the 

 lobes of the liver. 



The jaw (PL v, fig. 11) is 44 mm. long, smooth, boomerang- 

 shaped, ends tapering to a blunt point, cutting margin with 

 a slight median projection. 



The radula (PI. vi. figs. 14, 15) measures 10 x 3 mm., is strap- 

 shaped, formula, 185 rows of 45 : 22 : 1 : 22 : 45. ; the rachidian 

 is single, narrow, about the length of its base, sagittate at the 

 root, slender in the stem, lanceolate at the apex, basal plate 

 expanded posteriorly ; laterals more bulky than the rachidian, 

 unicuspidate, broadly ovate, apex acute, projecting past the basal 

 margin, alate angle slightly expanded ; the remoter laterals pass 

 gradually into the marginals, which are characterised by single, 

 entire, oval, much inclined cusps. 



The classification of this species hithei'to accepted seeming to 

 the writer in disaccord with its real relationships, he would prefer 

 to intercalate it among other Australian snails as follows : — 



Family HELiciDiE. 



Foot flat, pointed, without mucous gland or pedal line ; mantle 

 without appendages ; tentacles long and tapering. 



