SMITH : AUSTRALIAN LAND-SHELLS. 85 



variety of form, coloration, or size, as many of the species wliich 

 are met witli in the north and north-east of the continent. 



The predominant forms among the Helicea belong to the sections 

 Rhagada, Hadra, and Patula, and the Bulimi are restricted to the 

 sub-genus Liparus. 



A remarkable feature is the scarcity of operculate forms, a 

 characteristic which is applicable also to the rest of Australia. 



Only four species are known from the West, of which one was 

 obtained by Mr. Walker. 



Besides the rarity of Operculata, it may be as well to notice 

 the absence of certain other forms of land-mollusca. No species 

 of Vitrina, Helicarion, Pupina, or Biplommatina, and not a slug 

 of any kind are yet known from this region, but this may arise 

 from the fact that the country is, comparatively speaking, 

 unexplored conchologically, and it is more than probable that when 

 it has been further investigated it will prove to be much richer 

 in terrestrial forms. 



Another feature in connection with the land- shells of West 

 Australia is their distinctness from those which occur on the opposite 

 side of the continent ; and, only in one instance, does the same form 

 occur in the north and west : a single species is also common to the 

 south and west. This difference may be due to the fact that large 

 desert tracts divide the eastern from the western portion of the 

 country. How far some of the species range eastward we do not 

 know, for the country inland is practically a terra incognita to the 

 conchologist. 



The first land-shells collected in West Australia were obtained 

 by Capt. P. P. King, and were described by Dr. Gray in 1825. 

 Subsequently MM. Quoy and Gaimard, during the voyage of the 

 "Astrolabe," discovered a few other species, which were described 

 by them in the account of the voyage of that vessel in 1832. Menke 

 in 1843 described three new species collected by Dr. Preiss ; a few 

 new forms obtained by Dr. Bacon were published by Benson in 1853 

 and 1854 ; and a few other species have also been described by Reeve, 

 Pfeiiier, Cox, Brazier, Angas, and myself. 



With regard to the relationship of the fauna of West Australia 

 it is difficult to make any comparison. It appears, to some extent, 

 to have a specialized fauna of its own. True, some of the forms 

 of Hadra bear relationship with certain species which occur in the 

 northern parts of the continent, and some of the Bulimi have repre- 

 sentatives in South Australia. However, the group Rhagada among 

 the Helices and the Bulimi of the section Liparus are characteristically 

 West Australian forms. 



Bulimus Kingii is the only species of West Australian land-shells 

 of which the animal has been described and figured. An account 

 of this species is given by Quoy and Gaimard under the name of 

 Helix trilineata. They also make a few remarks on the animal 

 of B. melo. 



