The term “protocephalon” as used by Snodgrass (1938) applies to that portion of the head which lies anterior to the mandibular segment. As defined by him it is composed of the “prostomial acron” and a postantennal segment. The term “acron” has been used in somewhat different senses by different authors and to avoid confusion I have introduced the term “blastocephalon” instead. The blastocephalon may be defined as that portion of the head which includes the labrum, clypeus and occulo-antenna1 region. In the germ band it appears as an expanded anterior region, the cephalic lobes, which forms a sort of early embryonic head, hence the name. The posterior trunk-like region of the germ band may then be called the blastocorm.

Very few papers have been published on the life history of pseudoscorpions. The literature has been summarized by Kätner (1927), J. C. Chamberlin (1931), Beier (1932) and Roewer (1936-1940). The following contributions are based upon observation of two species of pseudoscorpions which were kept in captivity.

I should like to give sincere thanks to Dr. J. C. Chamberlin for reading the paper and giving valuable suggestions, to Dr. C. C. Hoff for determining the chernetid pseudoscorpions, to Mrs. Rosalie Rogers Talbert for assistance in maintaining and feeding the pseudoscorpions; and to my wife who has aided in the work.

The object of this paper is to summarize some of the latest research work that has been done concerning the amino acids in insects and especially the research work in which I have collaborated.

The Amino Acid Molecule

An amino acid is an organic compound which contains a grouping with gcidic properties. Such a grouping in organic compounds is the carboxyl group.

Further study, following submission for publication of the generic revision and species list (Frick, 1952), has resulted in changing the generic position of nine species, in making five synonymies, and in the addition of three subgenera and fifteen species to the list.

Malloch (1913, 1914) was reluctant to synonymize many North American species with European species due to the lack of positive identifications. Palaearctic species in the family Agromyzidae are now well defined as a result of the efforts of Hering, de Meijere, and Hendel (Hendel, 1931-1936). Therefore, the writer has not hesitated to snonymize North American species when there was an opporrunity to study specimens, including leaf mines as well as adults, of the species in question.

The prevailing method of preparing glycerine mounts of nematodes consists essentially of transferring the specimens from the fixative to 1.5-2.0 per cent glycerine in water and then allowing the water to evaporate very slowly until the nematodes are in pure glycerine. By this method evaporation is completed in not less than four weeks as any attempt to hurry this process will distort the specimens. A desiccator is used to complete the removal of the water from the glycerine.

It is important to record in the literature at this time the occurrence of Roeseliana roeselii (Hag.) in the province of Quebec. The specimens were collected by J. R. Beaudry at Ville Saint-Laurent (12-VII-52, 2 ♂ ♂; 13-VII-52, 3 ♂ ♂) and at Montreal (16-VII-52, 1 ♂; 19-VII-52, 1 ♂).

This particular species is of common occurrence in Europe. Its distribution is given by F. E. Zeuner as “Spain, France, England, central, east, and south-east Europe, southern Ural Mts., Tomsk, and Siberia.”