136 MONOGRAPH OF BRITISH LAND AND FRESHWATER MOLLUSCA. 
GENUS MWILAX Gray. 
(Amalia, Moquin-Tandon ; Lallemantia, Mabille). 
The genus Milar (Milax, a word 
formed by a transliteration of Lima’) 
was instituted by Dr. Gray in the 
Cat. Pulmon. Brit. Mus., published 
on May Ist, 1855, but in which the 
preface was dated March 29th. 
The term JMilav  antedates 
Mogquin-l'andon’s name of Amalia, 
which was published in his “ Hist. 
Moll. Terr. et Fluv. France,” n., 
p- oe on Sept. 10th, 1855.” The 
preface to that work, though dated 
March 15th, was really issued with 
the third part on Aug. Ist, while 
the fourth part, in which the term 
Amalia was first instituted, did not 
appear until Sept. 10th, 1855, the 
misleading date of the preface to 
the work having led to the wrongful 
use of Amalia. 
With this genus Dr. J. E. and 
Mrs. Gray have been associated in 
recognition of the institution of the 
present group and of the impetus 
their conchological works have had 
upon the popularization of con- 
chology generally. 
In this country we have but two 
species, which, although placed by 
. Pollonera in separate sub-genera, 
= Tandonia and Pirainea, do not show, 
at least in British specimens, the 
differential characters he has as- 
signed to them, but are, in fact, somewhat closely allied in structure 
and aspect, but according to Dr. Simroth, within certain limits, no genus 
is so unstable in its organization as is Miélar, a group which, in his 
opinion, is only at the outset of its course, in the formation of species 
for the future. 
Generic Characteristics.—ExrerNa.Ly, in Milax the body is longi- 
tudinally grooved, and acutely keeled the whole length of the back. ‘lhe 
MANTLE is shagreened or delicately wrinkled, bears a bluntly lenticular 
r horse-shoe shaped groove, more or less completely circumscribing a 
comeniiat prominent postero-central part which simulates a smaller, 
superposed mantle; the RESPIRATORY ORIFICE is placed on the right side 
behind the centre of the mantle, and is not cut by the anal channel, 
