MOLLUSCA OF INDIA. 61 
creeping about 2 inches in length; the colour of the shield and 
upper part of the body is black, elegantly spotted with yellow ; the 
under surface of the foot light yellow, and divided into three nearly 
equal bands; the edge of the foot is brown with transverse sulci. 
Besides the typical variety, which is that now described, a second 
is occasionally met with; it is characterized by the spots being of a 
pure white.” 
Professor Allman then proceeds to show how this genus differs 
from Arion and Lima, and considers that it approaches more nearly 
to the former than to the latter. I am inclined to think it is 
equally distant from both—the position of the generative aperture 
in Arion just below that of the respiratory, which is an excellent 
character, places it very wide of that genus, much more than the pre- 
sence of the mucous gland at the extremity of the foot separates it 
from Limaw; while the forward position of the respiratory aperture 
is not a character of very much importance ; whereas the position of 
the generative orifice in Arion, and adjacent to the respiratory, alters 
altogether the arrangement and form of the other organs of the 
body, the site of muscle-attachments, &c. The size of the rudi- 
mentary shells in these genera of slugs does not very much affect 
the question of their respective affinities. 
I have lately, owing to the kindness and liberality of Dr. A. 
Giinther, of the British Museum, been able to examine the animal 
of this genns more closely, and look at other characters, which place 
it altogether in a more remote and isolated position as regards both 
Arion and Limax. At the same time the possession of species of 
the genus Anadenus, Heynemann, from the Himalaya, which I have 
already figured and described, shows that Geomalacus is more nearly 
related to that genus than those above mentioned. It is for this 
reason, and that we may compare the characters of both, that I 
enter more fully into and figure some of the internal organs of this 
very restricted European genus. 
As the position and attachment of the large retractor muscles in 
these creatures bear somewhat the same relation to its body, as 
regards its outer form, when in motion or at rest, as the develop- 
ment of the muscles in the Vertebrates effects and modifies the size 
and form of their skeleton, importance should be paid to this part 
of their anatomy ; and it is found that in many genera the position 
of these muscles where given off changes from a posterior to a more 
anterior one, showing in this respect a greater departure from some 
original type. 
Gromazacus macutosus, Allman. (Plate XII.) 
Geomalacus maculosus, Allman, Ann. & Mag. Nat. Hist. xvii. 
p. 297, pl. ix. (May 1846); Forbes & Hanley, vol.iv. p. 12, pl. FF F*. 
f. 5 (1853). | 
G. maculatus, Adams, Genera, p. 228, pl. Ixxx. ff. 4, 4a (1858). 
? Limax anguiformis, Morelet, Moli. Port. p. 36, pl. i. f. 1. 
G. maculosus, Gwyn Jeffreys, Brit. Conch. 1. p.129, pl. v. £3 (1862); 
Bourguignat, Class. Fam. Moll. vivants, p. 14 (1877) ; J. Mabille, 
