AUSTRALIAN LAND SHELLS. 9 



18. Helix Wilcoxi. Cox. Plate IV. Fig. 12, natural size and 

 magnified. M.C. 

 Cox, Pro. Zool. Soc, 1864, p. 594. 



Shell minutely umbilicated, globosely-conical, very thin, shining, 

 hyaline, glassy-white or very pale yellow, finely, regularly, and 

 closely striated across the whorls ; spire conical, obtuse, suture finely 

 margined ; whorls 6, slightly convex, the last obscurely keeled 

 below, equalling the rest in height ; aperture slightly oblique, 

 lunate ; peristome simple, thin, straight, columellar margin very 

 briefly expanded at the base, and. half covering the umbilicus. 



Diameter, greatest 0-18 ; least 0-16; height 20 of an inch. 



Habitat. Clarence and Eichmond Rivers, on leaves of trees. Mac- 

 Gillivray. 



VII. SECTION HYALINA. Pfr. Vers. p. 124. 



* H. Sydneyensis. * H. albumenoidea. 



* H. nitida. * H. minima. 



* H. splendidula. * H. Lyndhurstensis. 



* H. ductilis. * H. subangulata. Pfr. 



* H. fricata. 



19. Helix Sydneyensis. Cox. Plate IX. Pig. 16 slightly mag- 

 nified; and Plate XVIII. Pig. 3 natural size, 3 a. magnified. M.C. 

 Cox, Catalogue of Australian Zand Shells, 1864, p. 37. 



Shell umbilicated, depressed, rather solid, shining, transparent, faintly 

 and closely striated with fines of growth, yellowish-horny above ; 

 spire slightly elevated, roundly obtuse, suture very obsoletely 

 margined ; whorls 5 to 6, slightly convex, the last not descending 

 in front, convex, slightly depressed above ; base flatly convex, 

 opaquely whitish, umbilicus very large, equalling one-fifth of the 

 diameter of the circumference ; aperture diagonally oblique, some- 

 what roundly and obliquely lunate ; peristome smooth, straight, 

 margins converging, columellar not dilated or expanded. 



Diameter, greatest - 53 ; least 0'45 ; height - 25 of an inch. 



Habitat. Abundant in gardens and cellars about Sydney. Cox. 



In the above there is frequently present a spiral reddish thread 

 below the suture. Careful comparison with specimens of the 

 European H. ceVaria shew in that species greater flatness of spire 

 and of the shell generally, and there is a decided difference in the 

 shade of colour. H. Sydneyensis is very closely allied to H. 

 glaberrima from the Solomon Islands, in the description of which by 

 Pfeiffer and Eeeve no mention is made of the obsoletely striated 

 markings. 



20. Helix nitida. Midler. Plate IX. Pig. 15, 15 a. natural 

 size and magnified. M.C. 



Mailer, Hist. Nat. Verm., Vol. II., p. 32. 



Shell umbilicated, depressly-globular, thin, shining, transparent, 

 very faintly transversely striated, horny, tawny throughout ; spire 

 slightly elevated, obtusely rounded ; whorls 5, moderately convex, 



