158 Annah of the. South African Museum. 



E. R. Sykes has chronicled the existence of a sinistral specimen. 



Layard's note on this species runs : 



" Helix lucana, Miill. Another variable and rather widely dis- 

 tributed species, but as yet I have not procured it beyond the 

 limits of the Colony, and in it, chiefly along the Southern seaboard. 



" The brown variety, with white band along the suture, is 

 found pretty abundantly about Kalk Bay, in the sand under bushes. 

 A smaller variety, with a brownish purple mouth, is found in the 

 George District; a small variety (diam. 17, alt. 13 mm.) with a 

 white mouth, is not uncommon at Bredasdorp, while a large 

 white form (diam. 32; alt. 25| mm.) exists at Mossel Bay." 



The first of the above forms is, of course, the typical lucanus, 

 and the last must be referable to bleached specimens of ambiguosus. 

 The other two are more open to doubt, as I have been unable to 

 trace an authentic example from either of the localities mentioned, 

 but it is reasonable to infer that the form from the George District 

 may be T. ambiguosus, var. compactus, described hereafter ; and 

 that from Bredasdorp, the doubtful species No. 3 on p. 176. 



T. lucanus has possibly undergone a slight diminution in size 

 during recent times, for in a subfossil set, collected by J. S. Gibbons 

 at Kalk Bay, are solid, coarsely malleated examples attaining such 

 dimensions as : 



Diam. maj. 38'6, min. 3TO ; alt. max. 29-5 ; apert. 2T1 x 14-9 mm. 

 and 32-4, 25' 5 ; 22-0; 15-5x13-7 



but, in other respects, not varietally separable from Type. The 

 smaller of these shells is remarkable, in that its thick, white callus 

 helps to make a practically continuous peristome, it being almost 

 impossible to mark where the latter ends and the callus begins. 



I have collected at Kornrnetje a white-shelled mutation of 

 lucanus, agreeing with the normal form in other respects ; the 

 shells found inland at Montagu are slightly smaller and thinner 

 than the coastal race, but cannot be considered even varietally 

 distinct. 



While in its radula and in most of its other organs T. lucanus 

 agrees closely with those species which have already been described, 

 in its depressed shell and in some features of its reproductive 

 system it departs considerably from the preceding forms, and 

 bears a slight superficial resemblance to the genus Dorcasia. The 

 complete detachment of the vas deferens from the side of the 

 penis has doubtless been brought about by the extraordinary 



