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common frog abound. With the fishes the case is somewhat different, and 
this fact is interesting in connection with the recent observations of M. 
Victor Fatio on certain species of fish in the Swiss lakes. Although the 
lakes swarm with fish, these belong only to five species, three of which, 
pertaining to the genus Salmo , are regarded by Professor Kessler as new, 
although allied to or intermediate between the well-known European 
species Salmo fario , S. trutta, and S. lacustris. Professor Kessler proposes 
to name them Salmo ischan, hegarcuni , and bodschac. Of the other two 
species, one very closely resembles Capo'eta fundula Pallas, a Central 
Asiatic species ; and the other most nearly approaches Barbus Cyri, 
d.e’ Filippi. The last-named species inhabits the streams flowing into the 
lake from the mountains. 
Bemodex folliculorum . — Whether Butler’s reference to the t( maggot in 
cheesemonger’s nose ” is to be taken as evidence that the philosophers of 
his day had any knowledge of the existence of the curious parasite in the 
follicles of the human skin to which the above name has been given, is a 
question that we may leave to the learned in such matters, who may at the 
same time settle whether cheesemongers are more subject than other men 
to the peculiar pimples which betray the presence of the parasite. Our 
first definite knowledge of it is due to Dr. Simon, of Berlin, who discovered 
it in 1842, by the assistance of Erichson recognized its affinity to the mites 
(the group to which the itch-parasite also belongs), and described it pretty 
f ull y under the name of Acarus folliculorum. Professor Owen, in 1843, 
founded a new genus for the reception of the parasite, and called it 
Bemodex ; Erasmus Wilson, who regarded it as a worm, named its genus 
JEntozoon ; M. Paul Gervais, in ignorance of Professor Owen’s name, gave it 
the generic name of Simonea ; and M. Miescher, changing both names, 
christened it Macrogaster platypus. M. P. Megnin, a well-known student of 
the Acarina, has just published (in the “ Journal de l’Anatomie et de la 
Physiologie,” 1877, No. 2) a long and interesting memoir upon Bemodex 
folliculorum, containing a history of our knowledge of the animal, a discus- 
sion of its zoological affinities, a full description of its structure, and an 
account of its development and habits. Like its discoverer and most of 
the zoologists who have described it, he refers it to the order of Mites 
{Acarina), and, following M. Paul Gervais, he regards it as forming a dis- 
tinct family {Bemodicidce) in that order, nearly related to the Bear Animal- 
cules {Arctisca or Tardigrada), so well known to all microscopists, on 
account of their wonderful faculty of coming to life again after desiccation. 
These creatures are minute, somewhat worm-like parasites, from t |q to 
about ^ inch in length, having a more or less oval cephalothorax, bearing in 
front a sort of rostrum composed of mandibles, maxillae, palpi, and ligula, 
and along its sides four pairs of short, three-jointed feet, each furnished with 
a pair of blunt claws. Behind this part comes a thinner, finely-ringed 
abdomen, variable in length, but usually longer than the cephalothorax. 
The little animals are found in the sebaceous and hair follicles of the skin 
in man and some animals. They are said by M. Megnin to be viviparous, 
the females producing small footless, contractile larvae, without any mouth 
organs ; these, shortly after their birth, acquire three pairs of conical 
tubercles, which serve them as feet for creeping about. A change of skin 
