The present paper is concerned solely with methods of studying the chromosomes, their number, morphology, and behaviour, in insects. Much has already been written on general cytological techniques used in the study of animals and plants (1, 2, 3 and 4) but no special treatment regarding insects has as yet appeared. The techniques outlined in many standard text books are largely obsolete, and reprints of current improvements are frequently not available in the specialised entomological library. Therefore a review of the procedures commonly followed may not be out of place as a guide to the non-specialist.

Runs in the couplet with severini in my key (Miridae of Illinois, 1941) but distinguished by black color on apical half of femora, base and apex of tibiae.

♂. Length 5.1 mm., width 2.34 mm. Head: width 1.12 mm., vertex .51 mm.; black, a small yellow glabrous spot each side of vertex bordering eye. Rostrum, lengt 1.08 mm., just reaching middle of mesosternum, yellowish, apical half blackish.

In a revision of the Acontias contained in the Canadian National Collection two species which have been unnamed in the Collection for some time appear to be undescribed. I offer the following descriptions.

The clover or brown mite, a common pest of cultivated plants, is frequently mentioned in the literature as occurring on orchard trees as well as on a variety of grasses and herbaceous plants. Its habit of entering dwelling at various seasons has even caused it to be included in he category of household pests.

More or less comprehensive lists have been published of the Odonata of the Canadian provinces and recently Mrs. Gloyd ('39) has brought together all the available records for Alaska, but very little has yet appeared regarding the species which inhabit the other northern parts of North America, viz., Newfoundland, Labrador and the Northwest and Yukon Territories of Canada.

This is one of a series of papers on the desert life of the Big Bend Region of Trans-Pecos, Texas. The area concerned is mainly in Presidio and Jeff Davis Counties; the former one of the largest counties in the United States. Situated about twenty miles north of Presidio in Presidio County is the mining town of Shafter which lies in the heart of the Chinati Mountains.

The present paper is the result of a study of the food plant relationships of Exema Lac. and Arthrochlamys Ihering (Chlamys Knoch) in Canada. The study has shown that the species have strong monophagous tendencies, and that a knowledge of food plants is the key to an understanding of those which have been confused under the names Chlamys gibbosa and C. plicata.

The present sunmary of Gonia sens. lat. is made necessary because of a large number of undescribcd species recently segregated in the Canadian National Collection and by Dr. H. J. Reinhard. The group covered is the same as that summarized by Tothil (1924) and Morrison (1940), the latter work containing all records of species up until 1940 and with illustrations of the male genitalia of each species. It becomes only necessary then to present descriptions of new species and to fit all species into their proper restricted genera (in Townsend's sense): a key to all described North American species and illustrations of the new species are included.

The crane-flies considered herewith are all from Western North America, from British Columbia to California. The names of the collectors and the location of the type material are indicated at the end of the individual specific accounts; where not stated to the contrary, such types are preserved in my own collection of these flies.

There are ten species of Lachesilla recorded from the United States. The following three have been found on corn (maize) during this work: L. nubilis (Aaron), L. pedicularia (Linné) and L. forcepata var. major Chapman, the first being the common species on corn around Urbana and Champaign, Ill.

In the ‘Contributions’ Vol. V (2) 80/1, Benjamin has attempted to straighten out the synonymy of this species and the allied praefica Grt. Unfortunately, after carefully checking over the material in our Collection, I find that he has only added to the nomenclatorial confusion.

Heteropogon vespoides was described in 1878 by Bigot from a single male specimen. The rather indefinite type-locality was given merely as California, as was often the practice in those days. The description was written in French, Bigot's native language. However, an excellent translation was made by Back (Trans. Amer. Ent. Soc. 35:329, 1909) who appended thereto a note to the effect that he did not believe that this species was known to recent collectors.

Resembling T. gillettei but somewhat larger. Two inner pairs of processes of aedeagus of about same length with innner pair not bent at middle and dorsal spine as long as shaft is wide. Length 4.5 mm.

Color: As in heavily marked T. gillettei V. D.

In his recent Revision of the Oecophoridae (1941, Proc. U. S. N. M. Vol. 90, No. 3107) Gates Clarke (p. 196) records the larva of Depressaria betulella Bsk. as feeding on both Betula and Ostrya. As material bred by us from Ostrya this past summer in the Ottawa region did not at all match with our series of the birch-feeder I have made a genitalic study of the species of this group in the Canadian National Collection in order to check up on the matter.

In the literature on forest entomology there has been considerable confusion regarding the true identity of the two species of Dioryctria feeding on spruce in North America. Superficially the adults of these species resemble each other so closely that the one is easily mistaken for the other. In seasonal history and habits, however, they differ very materially.

The dominant genus of Larrine wasps in warm countries throughout the world is Motes Kohl (olim Notogonia Costa seu Notogonidea Rohwer), but it is rather poorly represented in the Nearctic fauna. Hitherto only five species have been recorded from the United States: argentatus (Palisot de Beauvois), 1811, aequalis (Fox), 1893, nigripennis (Fox), 1893, occidentalis (Viereck), 1902, and subaequalis (Rohwer) 1909. To this roster may now be added the following two very distinctive southern forms.

The larvae of certain Trichoptera are known to fashion into their cases structures to which a “ballast” function has been ascribed (Stuck, 1900; Buchner, 1905; Rousseau, 1921; Lloyd. 1921; Needham and Lloyd, 1937). Of forms living in the Ithaca, New York, region the cases of Stenophylax scabripennis, Halesus guttifer, Neophylax, and Goera calcarata are offered as examples. The term “ballast” has been used to imply a balancing as well as a weighting purpose depending upon the particular species under discussion. Rousseau (1921) in describing the general types of caddis cases says “…. in the absence of current, they (the cases) do not in general offer such adaptations as those which we find in the larvae living in moving water.

Two hitherto unnoticed generic names in the sphecoid wasps have recently come to my attention. Although the first, Dryphus, is clearly a synonym, as may also the second, Stercobata, be, nevertheless, since both will preoccupy any future usage of these names far valid generic entities, they are noted here in order that they may eventually find their way into the proper universal lists of generic names of animals.

Notes on several previously known generic or subgeneric names are appended at the end.

Through the kindness of Mr. Don B. Stallings, of Caldwell, Kansas, the author received for examination a small series of an Incisalia that appears to represent a race of the eastern I. henrici Grote and Robinson. This series was later augmented by about 40 more specimens from Mr. Stallings and 32 from an adjacent locality taken and sent by Mr. Robert Whittaker, of Eureka, Kansas. With this series it was possible to draw up a good description of the subspecies and to obtain quite accurate ideas as to the extent of its variation. In addition to this material, both Mr. Stallings and Mr. Whittaker sent further specimens for comparison, for which many thanks are due.