142 MILAX GAGATES. 
bulging atrium, is probably preceded by mutual exchange of blandish- 
ments and stimulatory actions, the operation itself occupying many hours, 
this great length of time being necessary to allow time for the secretion of 
the spermatophores and for their mutual transference. 
The eggs are slightly oval in shape, transparent, delicate, and thin 
shelled, and measure 2’ mill. in length and 13 mill. in width. They are 
agglutinated together by a colourless mucosity and deposited in moist 
spots in the soil, or beneath some protection, and hatch in less than a 
month ; the young, according to Prof. Krause, when excluded are white, 
with a semi- circular black band on the mantle, and the margin of the 
pallial gutter filled with pigment; they may afterwards become tinted with 
orey, especially towards the end of the keel, following this by assuming a 
reddish colour, with a greenish tint at the sides, and “although all do not 
follow in the same line of colour development, yet as they increase in 
size they gradually assume the adult coloration. 
Food and Habits.—Milax gagates is a shy and retiring species, and 
of nocturnal habits; though more active than its congener, it is also 
addicted to a somewhat subterranean mode of life, but may be met with 
crawling on the earth during the day after long- continued or heavy rain. 
Though essentially a ground slug, frequenting heaps of decaying veget- 
able matter, the foot of old walls, hedgerows , and amidst thick herbage or 
tufted plants, in gardens, ete., yet it has at times been noticed crawling up 
the trunks of apple and lime trees, and upon old walls. 
It can spin mucous-threads easily and well, and quickly avails itself of 
this method of reaching the ground when placed in distasteful positions. 
When at rest it assumes, according to Dr. Norman, a more rounded form 
than any other British Limaz, so contracting itself that its height is but 
little-exceeded by its length. 
Though perhaps chiefly vegetarian, and very destructive to young plants 
and underground roots and bulbs, yet it is also not only carnivorous but 
predaceous; eagerly destroying and devouring /elices and slugs, and even 
sickly or weaker individuals of its own kind. 
In captivity it is very omnivorous, as out of 195 different kinds of food 
offered to it by Mr. Gain it ate more or less readily 173, though only 
devouring with eagerness potato tubers and the root of carrot. 
Fossil.—It has been reported from the Pleistocene deposits near Port- 
land Bill, Dorset, on the authority of Prof. Prestwich (J. C. Mansel-Pleydell, 
Moll. Dorset, 185 98). 
Variation.—The external variation in Milaa ga gates would appear to 
be more largely geographical and less sporadic than in many species, 
although M. Bourguignat describes it as a variable species, sometimes 
ereenish or yellowish or even bluish in colour. 
British specimens are generally smaller, smoother, more pellucid, and 
paler than those inhabiting more southern and warmer districts. The 
Mediterranean forms are often large, black, more opaque, and more rugose 
than our British specimens, and the black pigment tends to invade the 
side-areas of the sole; this major form has been especially noticed in 
Algeria, and has been regarded as a sub-species by Prof. Cockerell, under 
the name of Amalia mediterranea. In Sicily, this pigmentation of the 
sole is not so far advanced, the side-areas being still grey; this transitional 
stage has been distinguished as forma sémilis, while closely-allied indi- 
viduals from Morocco have been differentiated as forma atlantica Ckll. 
