68° QUEENSLAND AGRICULTURAL JOURNAL. [1 Juny, 1899. 
(3.) The species of Vaginula, although very numerous, only exceptionally 
extend so far from the equatorial region as is the latitude of Brisbane—27 degrees 
south—where they have to hibernate.* 
(4.) For some considerable period prior to their discovery, the Brisbane 
Botanical Gardens had received, from time to time, consignments of plants from 
regions in which either Vaginula Slugs are already known to occur, or may be 
expected with great probability to be found. And the fact that they remained 
undescribed until 1889, and have not as yet been identified with species indigenous 
to other lands, is intelligible when itis recognised that the Vaginulid@ of certain 
climes, apparently rich in species—e.g., in the Hast Indies—have exceptionally 
been made the objects of systematic study. They were, however, undoubtedly 
undescribed (selbstverstindlich neu, to use the words of Dr. Simroth in his 
first-mentioned memoir) when C. Hedley first made them the object of 
special study, though at the time of writing this paper (September, 1889) it 
does not appear to have occurred to him that they were not truly indigenous 
to Southern Queensland. It is satisfactory, however, to be able to state that 
the opinion of the writer with regard to this question is now shared by so 
competent an authority; for C. Hedley, in a recent communication, states as 
follows :— 
Talways did suspect these slugs to be foreign, and your information that they 
have increased so as to count amongst “Pests” confirms the idea. That the many 
active collectors who have searched Queensland for Mollusca, including ourselves, 
have never met with it elsewhere is a suspicious circumstance. That it should occur 
in the Botanical Gardens suggests introduction with foreign plants. It is remark- 
able that any species should first be made known to science in the person of erratic 
wanderers from native soil. You will recall the case of Bipalium hewense as a 
parallel one. I cannot at the present moment remember another. On the other hand, 
this is a genus that might be expected to occur in Queensland. Two of its allies— 
Atopos australis, Heynemann, and A. prismatica, 'Taparone-Caneffri—are already 
reported from your territory. From New Caledonia a still nearer relation is found 
in Vaginula plebeia, Fischer.—Australian Museum, in lit., 15-5-99. 
NATURAL ENEMIES. 
This aspect of the subject has not as yet claimed attention. None of our 
native birds have been observed engaged in feeding upon these slugs, though 
it is anticipated that the latter might be favoured by the Ibis. The same remark 
applies to our indigenous batrachians—frogs and toads; but their numbers and 
rate of increase seem to far exceed the capabilities of this description of possible 
slug-enemies. No Acari have been found preying upon the beetle larve, as is 
sometimes the case with ordinary slugs elsewhere. But on two occasions M. B. 
Bernays “has noticed a steel-blue red-headed centipede (? Heterosoma sp.), about 
4 in.in length, on the backs of large individuals of the blackish-coloured variety 
of Vaginula, which latter were practically in their embraces. |The slug in each 
case at the time moved vigorously, but its captor seemed to have full charge. In 
fact, it seemed to be a struggle for existence on the part of the former.” This 
predatory habit, however, is one which, for obvious reasons, could not be availed 
of in practical procedures having for their object the repression of the pest. 
Domestic poultry—including ducks, which are under certain circumstances 
rayenous true slug-consumers—do not appear to affect Vaginulas, or, if they 
partake of them, have not appreciable influence in lessening their numbers. 
PREVENTIVE MEASURES. 
As this slug has so well established itself in the district, and has‘manifested 
not only its adaptability to our climate, but also its powers of rapid increase in 
numbers, as well as its capability of injuring garden plants, its further dissemination 
*The Vaginula Slugs are essentially tropical or subtropical animals, occupying a zone 
extending about 20 degrees on each side of the equator, being known to occur, almost invariably 
within this torid region, in South America, Mexico, West Indies, East Central Africa, Mauritius, 
the Serres Ceylon, Burmah, South China, and the East Indies. Exceptionally they pass 
beyond this limit, being found (according to Dr. Semper) on both sides of South America to 38 
degrees of south latitude along the coastal districts, and they have also been reported from 
Hongkong (23 degrees north latitude), ‘ 
