1898] NOTES AND COMMENTS 85 
the A. hortensis group is the lower portion of the free oviduct much 
larger and more globose than the upper. Again, in the paper, the 
validity of A. fuscus, externally very much like A. subfuscus, is 
admitted by Mr Collinge who previously rejected it. This is not 
to be wondered at since, in another paper on four species of the 
same genus, published about the same time in the Journal of 
Malacology (vol. vi., pp. 7-10, pl. ii.), almost the only evidence of 
external difference between A. empiricorum, A, ater, and A. lusi- 
tanicus given by Mr Collinge is a short series of measurements 
pointing to the fact that the second species is larger than the first. 
Of course it is probable that our islands contain more species 
of Arion than many of us used to imagine, and Mr Collinge has done 
much to arouse us to the truth about them; but, before all the 
species which he and his continental friends would give us are 
recognised by thinking malacologists, still more careful and detailed 
work must be done upon the genus. We have been so. busily 
criticising the weak points in the paper that we have only hinted, 
by quoting a few figures, at the prodigious amount of work which it 
must have entailed. There only remains for us to express the hope 
that other workers will come forward and supplement what is a 
valuable contribution, from an anatomical point of view, to our 
knowledge of the genus Avion. it 
In the other paper we have “the description of two new species 
of slugs of the genus Parmarin from Borneo” (Proc. Zool. Soc., 
1897, pp. 778-781, pl. xliv.). One of these the author considers 
intermediate between the genus in which he places it, and Micro- 
parmarion ; in fact it leads Mr Collinge to the conclusion that no 
line can rightly be drawn between the two genera. 
AMERICAN ISOPODS 
Mr J. E. BeNepicr on March 24 published a paper on ‘“ The 
Arcturidae in the U.S. National Museuin” (Proc. Biol. Soc. Wash- 
ington, vol. xii., pp. 41-51), in which there are several interesting 
features. He describes eight new species, and of each of them 
gives a good and intelligible ‘ habitus-figure,’ an adjunct without 
which the most lucid description of a new form is usually difficult 
and wearisome reading. Within the last twelve years the number 
of species in the genus Arcturus has been raised from five to 
twenty-five. Mr Benedict has therefore rendered a kindly service 
by supplying a key to this rapidly increasing group. As often 
happens, when new species appear, some of the old generic dis- 
tinctions have to disappear. Mr Benedict finds, for example, that 
in some species of Arctwrus the fingers are not simple, but bi- 
ungulate as they are in Astacilla. It appears, too, from his de- 
scriptions that Arcturus cannot invariably be distinguished from 
