AtJSTRALIAK LAXD SHELLS. 29 



4, quickly increasing, last not descending, depressed above, beneath 

 convex, bluntly angular ; aperture oblique, lunately-rounded ; peris- 

 tome simple, thin, margins converging, right straight, angular in 

 front, columellar margin arched, neither dilated nor reflexed. 



Diameter, greatest 0*57 ; least 050; height 0'22 of an inch. 



Habitat. N.W. coast of Tasmania. Cox. 



Closely allied to 77. lampra, but differing in being more coarsely sculp- 

 tured, and wanting the extreme polish of that species, besides being 

 obtusely carinated, and having the aperture angular externally. 



74. Helix Wellingtonensis, Cox. Plate VII. Fig. 5, 5 a. 

 natural size and magnified. 



Cox, Pro. Zool. 5oc.,t867. 



Shell umbilicated, depressly-orbicular, sub-discoid, thin, with thread- 

 like riblets radiating sub-arcuately, frecjuently extending even to the 

 umbilicus, not shining, varying in colour from glassy-white to dirty 

 yellow ; spire small, scarcely elevated ; whorls 4, slowly increasing, 

 moderately convex, last more convex, not descending in front ; 

 umbilicus perspective, equalling \ of the diameter ; aperture mode- 

 rately oblique, lunate ; peristome simple, thin, straight, margins 

 approaching, columellar margin neither dilated nor reflexed. 



Diameter, greatest 027 ; least - 23 ; height Oil of an inch. 



Habitat. Mount Wellington, Tasmania. Cox. 



Closely allied to 77. Diemenensis, but differing in sculpture, in having 

 fewer and more thread-like ribs, and also in other respects. 



75. Helix Namoiensis. Cox. Plate XVIII. Fig. 10, 10 a. M.C. 



Shell deeply, rather narrowly umbilicated, thin, transparent, shining, 

 very smooth everywhere, light olive-brown, orbicularly depressed; 

 spire but little raised; whorls 5, rounded, last dilated, not descend- 

 ing in front ; aperture large, obliquely ovately-rounded, opalescent 

 within ; peristome simple, lip thin and sharp, darkened on the 

 outer surface, margins approaching, columellar margin slightly 

 dilated at the base. 



Diameter, greatest - 93 ; least - 75 ; height O'oo of an inch. 



Habitat. Namoi Eiver, N.S.W. Scott, 



This fine species presented to me by my friend, Mr. Walker Scott, 

 much resembles 77. strangei and other allied species in general 

 aspect, but is at once distinguished from it by the absence of any 

 sculpture on the upper surface, by the smallness of the umbilicus, 

 and by the dark outer surface of the peristome. 



76. Helix Harriett*. Cox. Plate XVIII. Pig. 9, 9 a. 



Shell largely and openly umbilicated, flatly-depressed, thin, pale, 

 yellowish-brown, shining, coarsely striated on the upper surface, 

 smooth at the base, irregidarly streaked with dark brown and yel- 

 lowish-brown ; spire flattened ; whorls 4, rather rapidly increasing, 

 fiat above, convex below, giving to the last whorl a blunt angled 



