F592 GENUS GEOMALACUS. 
body; the CeEPHALIC RETRACTORS, though resembling those of Aron, have 
a longer pharyngeal muscle, which is basally fixed behind the right 
ommatophore. The RENAL ORGAN or kidney completely surrounds or 
encloses the heart, which is, therefore, centrally placed in regard to that 
organ, as In Arion. 
Food and Habits.—The Geomuluci 
would appear naturally to subsist en- 
tirely upon the lichens and liverworts, 
but in captivity they will live and thrive 
on other and quite different food. 
In their native habitat they are very 
perfectly protected by their mimetic 
resemblance to their surroundings, and : 
by their nocturnal and crepusecular 
habits of life. 
Fossil.—Fossil remains attributed 
to Geomalacus and named pliocenicus 
by Sacco, have been found in the Upper 
Phocene beds of Fossana, Piedmont. Fic. 253.—Muscular system of Geomadacus 
(after Stmroth.) 
2 . * ; om gr. genital retractor ; 4. kidney, enclosing 
_Geographical Distribution. Nhe heart ; 2m. left tentacular retractor; 7.72. 
Geomalaci embrace but few species, and right tentacular retractor ; 7, pharyngeal 
. a retractor, 
these are contined to the west of Europe,  ‘“"“ 
though alhed sub-genera have been found in north-west Africa. 
The geological evidence of the former extension of the group is as yet 
but shght, but the finding of remains referred to Geomalacus in the Upper 
Phocene of Northern Italy leads us to infer that the genus had formerly a 
more eastern range, and it is probable that the evolutionary area of the 
genus was practically identical with that of Arion and the Limacidw 
generally, but Geomalacus is evidently a decadent and waning group, and 
has by stress of competition with more dominant forms become restricted 
to the extreme west of Europe, a last foothold heralding their final 
extinction. 
The genus Anadenus now expelled to the Himalayas is a closely-related 
but more primitive form than Geomalacus, but which on account of the 
easterly direction of its enforced migration, will probably outlive that group. 
Klee tT 
eee 
Autograph of Mr. W. Andrews, the discoverer of Geowalacus maculosus. 
