1380. ] Zoology. 133 
dark to see them. The two following days were cold and stormy, 
but on the 5th a few were still straggling across the fields. 
On the evening of the 23d inst., while crossing Boston Com- 
mon, I saw what seemed to be a similar migration, and in this 
case also the course was west.— Bradford Torrey. 
TRICHODINA PARASITIC ON THE GILLS OF Necturus.—I 
have to record a new habitat for this interesting ectoparasitic 
genus of Infusoria. I was recently searching the gill-filaments 
of a Necturus (which had died a few hours before in the 
attempt to swallow a young catfish) for specimens of a Polystome 
which I have described as occurring there, when I noticed the 
remains of a considerable number of Infusoria belonging to this 
genus. Only the aboral end of the body with its hooks and 
chitinous frame remained, the softer oral end being already dis- 
integrated. I did not succeed in identifying it with 7: pediculus, 
the ectoparasite of Hydra, which has been so admirably described 
by James-Clark (Mem. Bost. Soc. Nat. Hist., Vol. 1, No. 1), but 
it is possible that the examination of fresh specimens would prove 
it to belong to this species, which has also been indicated as 
occurring in the allantoid bladder of certain European newts 
(Busch, Miiller’s Archiv., 1855). 
Since writing the above I have had the opportunity of examining 
a fresh Necturus with the result that its Vorticellidan para- 
site also occurs in the urinary bladder. It is identical with the 
Hydra parasite, Trichodina pediculus—k. Ramsay Wright, Uni- 
versity College, Toronto. 
ZootocicaL Norrs.—The last number (3 of Vol. m1, Part. 1) of 
the Memoirs of the Boston Society of Natural History contains 
an elaborate essay, by S. H. Scudder, on the palæozoic cock- 
roaches, being a complete revision of the species of both worlds, 
with an essay towards their classification. This work of III 
pages is illustrated by six excellent plates. It appears that the 
palæozoic cockroaches are, like many other groups of animals of 
the palzozoic age, old fashioned, obsolete forms which have been 
replaced by more modern types, and we may add that the exist- _ 
ing cockroaches are to be congratulated that the shades of their 
ancestors have been thus recalled from their tombs and passed in 
review in a long and orderly procession. Dr. Hagen is saù- 
guine that noxious insects, such as the potato beetle, cotton 
worm and Rocky Mountain locust can be kept under, if not — 
exterminated, by the use of yeast fungus; we hope that these ~ 
fungi will take the place of Paris green as an insecticide, and 
trust another year to see experiments carried out upon an exten- 
Sive scale; we know that myriads of insects, such as the house as 
fly, are killed by fungi; why not myriads more, provided that the E ve 
Weather be sufficiently damp and warm for the growth of the 
fungus spores, a point not noticed by Dr. Hagen. In hot, dry 
