270 
ferences from the typical Helia in varying degrees of divergence. 
A sound arrangement and classification of our numerous species 
of so-called HHelices has been long felt, as the classification of 
Albers, revised by Von Martens, which has been in vogue for the 
past thirty years, has proved inadequate to the requirements of 
the systematist. It is, therefore, we hail with satisfaction the 
appearance of Mr. Pilsbry’s ‘Guide to the Study of Helices,” 
included in vol. IX., second series, of Tryon’s Manual of Con- 
chology, 1894-5, which is highly meritorious and will prove of 
exceeding usefulness. It furnishes us with a classification based 
on the extensive study of the soft parts—not upon the modifica- 
tion of a single organ, but all the organs of the animal are taken 
into account. 
The author divides the bibliography of the subject into five 
epochs, commencing with that of Linneus, and ending with the 
fitth, introduced by the publication of the second edition of 
Albers’ “‘ Die Heliceen” by Von Martens. Pilsbry modestly 
subordinates his work to this fifth epoch ; but those best familiar 
with his highly valuable services as a systematist will not doubt 
the epoch-making importance of his “Guide to the Study of 
Helices.” 
It is not desirable to attempt a review of the whole work, but 
so much of it as concerns the Australian fauna may be summar- 
ised. The classification is based upon, to quote the author :— 
Organs of protection (shell, mantle, integument of body). 
Organs of locomotion (foot, pedal grooves, tail gland). 
Organs of reproduction (genitalia, comparative size of eggs, &c.). 
Organs of nutrition (jaw, teeth, intestinal tract, kidneys, ‘te €) 
Nervous system, including sense-organs, such as tentacles, We. 
The Australian snails with a helicoid shell belong to the fol- 
lowing families :— 
ib. Without j jaw. RuwYTIDE 
II. With jaw. 
1. Foot-margin defined by a pedal groove ; peristome sharp. 
~- a. Marginal teeth with narrow, elongated, basal plates, and 
either l-cuspid and aculeate or bicuspid. Tail gland 
often present, sole of foot frequently tripartite. 
ZONITIDE. 
b. Marginal teeth with wide, short basal plates, with one or 
several cusps, the outer cusp never elevated on the 
middle cusp. Shell opaque, usually flame-colored, and 
rib-striate. ENDODONTID&. 
2. No pedal grooves, no tail-gland.. Dentition as in 
Endodontide.  Peristome usually expanded or reflected. 
Rk ti) : HELICID&. 
