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Families Orphnephilidae, Blepharoceridae and Rhyphidae

These three families are not especially well represented in the fauna of the United States and comparatively little need be said about two of them.

The Orphnephilidae are small brownish or yellowish flies without bristles or hairs. We have only one described species in this country, viz, Orphnephila testacea Ruthe, common to Europe and North America. Nothing is known about the transformations of any member of this family.

The Blepharoceridae, however, are insects of much greater interest and especially on account of their curious larvae and on account of an unusual arrangement of the viens in the wings which has been pointed out in the table of families. The adult flies look somewhat like mosquitoes but do not bite. The eyes are divided, the upper half containing large ocelli and the lower half small ones. The larvae are very peculiar looking objects, having appparently but seven segments and being furnished with conical leg-like structures on most of the segments. On the under side of the body is a row of circular suckers by which they attach themselves to rocks in swift running streams. Each of the suckers is surrounded by a little fringe of tracheal gills or there are tufts of such gills near the sides of the body. The pupa is formed within the last larval skin but subsequently the skin is cast so as to leave the pupa naked. The pupa also clings to the rocks, the skin of the back being hard and making a sort of scale over the body. On the underside, however, it is delicate and soft and furnished with six suckers by which it clings to the rocks so firmly that they can hardly be removed without breaking them. Comstock has watched the flies issue from the pupa skins. The pupae occur in groups so as to form black patches on the rocks. Each one rests with its head down the stream. The fly emerges through a split in the skin between the thorax and abdomen, working its way out slowly and holding itself upright in spite of the swift current. Where only a quarter of an inch of water flowed over their heads flies were able to hold to the pupa skins with their hind legs, the body being free from the water. The wings then expanded and they flew away. Where the water was deeper the flies were carried down the stream and possibly perished. The commonest species of the northeastern states is Blepharocera capitata Loew, which occurs in the District of Columbia, in central New York, in the White Mountains and in Canada.

The family Rhyphidae, the members of which have been called the "false crane flies," is composed in general of small flies with broadly rounded and spotted wings. It is a small family and only two genera are represented in this country. The early stages of none of our American species are known but in Europe they are described as long, slender, worm-like creatures which are found in decaying wood, in cow dung, in decaying fruit and even in dirty water.