TASMANIAN LAND SHELLS. 35 



are so much alike, and the specimens of H. architectonica in my collection 

 show so much tendency to vary within a certain limit, that I have no 

 hesitation in uniting under one specific head the three so-called species 

 given in Legrand's work as distinct. The variety was collected at the 

 last locality given. 



53. — Helix ( ) subrugosa — Brazier. 



Legrand, Col. for Mon., species 68. 

 Pro. Zool. Soc, 1872. 



Shell rather widely umbilicated, somewhat depressly-orbicular, thin, 

 shining, reddish-horny, subrugosely and obliquely striated, interstices 

 with striae much finer ; spire elevated very little ; suture channelled or 

 excavated ; whorls 5|, moderately convex, last flattened above the 

 periphery in form of a furrow in front, the furrow is distinctly seen j 

 umbilicus wide at top, equalling three-quarters of the diameter ; base 

 with striae same as upper surface ; aperture nearly diagonal, sub- 

 triangularly ovate ; peristome simple ; margins distant, sloping, and 

 expanded, basal slightly thickened and reflected. 



Variety a. — Pure white. 



Diameter, greatest 1 J, least \^ ; height, 1 line. 



Habitat. — Near Hobart Town, Mount Wellington, Chudleigh, Blue 

 Tier (Sim|son), Myrtle Bank (R. M. Johnston). 



" Of this beautiful species I received two specimens from Mr. W. 

 F, Petterd, collected by him near Hobart Town ; it m.ay be distinguished 

 from any other known species by the bold projecting out of the ribs, by 

 the interstices being of finer sculpture, and the depressed and furrowed 

 appearance of the last whorl just above the periphery." — Brazier. 



Very distinct. The sculpture represents H. Matliinnce (mihi) in 

 miniature by its widely separated bold strisB and striated interstices. 

 The depression of the last whorl near the ajDerture is very characteristic, 

 and renders the shell of easy recognition, for a similar feature has not 

 been noticed in any other of our many minute forms. The striae vary 

 somewhat in prominence and compactness, so much so that Mr. Beddome, 

 at one time, thought it would be advisable to create a new species for the 

 specimens from the Blue Tier under the name of H. Kemnar}(ce, but after 

 careful examination with a large series of examples I am confident that 

 it is but an individual variation. 



54. — Helix ( ) dispar — Brazier. 



Pro. Zool. Soc, 1870, p. 661. 

 Legrand, Col, for Mon., sp. 45. 



Shell umbilicated, depressly-convex, arcuately, coarsely, and sharply 



ribbed, interstices with very fine radiating striae, bright reddish- horny ; 



spire conoidly obtuse 3 suture depressed ; whorls 5 to 5 J, convex, last 



p 2 



