1879.] 135 [Hagen. 
being unmolested return and settle upon it. The dead flies lie several 
inches deep above the liquid petroleum. 
Note By Dr. HAGen. 
The interesting fact that some Diptera appear in immense num- 
bers as is often the case with Ephydra, is repeated by some Chiro- 
nomidae. Hydrobaenus lugubris was observed near Vienna (Wien. Z. 
B. Gesch. vit, 421), by Kollar on the border of water inundating 
a meadow. A space one thousand feet long and six feet broad was 
covered an inch high by living insects of this species, propagating or 
laying eggs. As the insect is only one line long, and as about one 
thousand would make a cubic inch, Kollar calculates the number 
must have been some 2,500,000,000 of specimens. I had observed 
the same fact under entirely similar conditions in eastern Prussia 
(Stett. Zeit., 1860). As the meadows are dry in summer, the eggs 
must have a very great vitality. 
The species from California belong to the genus Ephydra and is 
probably a new species. In Osten Sacken’s old catalogue, only nine 
species are mentioned or described, six from Hudson’s Bay, two from 
the West Indies, and one from Mexico, all unknown to me, and not 
represented in the collection. O. Sacken’s and Loew’s collections have 
only four species, one from the Mono Lake not named. I do not know 
E. halophila Park., (this name was long ago used by v. Heyden, 
though his species is now considered the same as EF. salinaria Bouche), 
and I cannot find a detailed description except the figure and the 
few characters in his guide, which proves that the Californian species 
is different. Dr. Packard has later described £. gracilis from Great 
Salt Lake, and £. californica from Clear Creek Lake, Cal., only 
larva and pupa. As he states them to be identical with those from 
the Mono Lake, of which species the collection of the Cambridge 
Museum possesses all stages, I can say that the species from Santa 
Cruz Co., is a different and smaller one. But I confess that I am 
unable to find all characters described by Dr. Packard in the larva 
of his EZ. californica in the larvae from the Mono Lake, where I see, 
for instance, clearly the spigot-like stigmata, described by Loew, 
which Dr. Packard stated he was unable to discover. Therefore 
until the identity of the Santa Cruz Co. species with E. californica 
is proved, I shall believe it to be a new species. 
Sees 
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