SMITUSONIAN MISCELLANEOUS COLLECTIONS 270 CATALOGUE OF THE DESCRIBED D I P T E R A NORTH AMERICA. BY C. R. OSTEN SACKEN. [second edition.] WASHINGTON: SMITHSONIAN INSTITUTION. 18Y8. 1 i I I ADVERTISEMENT. I The present work was undertaken by Baron C. R. Osten Sacken, of Russia, as a revision and extension of a Catalogue I of Diptera prepared by him twenty years ago, and published by the Smithsonian Institution in Volume III. of its Miscellaneous Collections. It is, however, not merely a new edition of the volume in question, but an entirely new work, constituting a valuable contribution to our knowledge of the entomology of Xorth America. SPENCER F. BAIRD, Secretary Smithsonian Institution. Washington, October, 1878. (iii) ( I P E E F A C E. The aim of this work requires no explanation. A complete inventory of a branch of entomological science, at a given- moment of its existence, is the best means for promoting its ad- vancement. Nor does the imperfection of a publication of this kind require an apology; any fair-minded reader is aware that the chief merit to be expected is completeness, and that whenever this is fairly attained, the usefulness of the work will far sur- pass its shortcomings. It remains for me therefore, only to ex- plain the rules that I have followed in preparing this Catalogue. Relation of the peesent catalogue to that of 1858. The first Catalogue of North American Diptera, published by me twenty years ago , was , and was meant to be , merely a com- pilation of the existing literature on the subject. It brought together a mass of references to the descriptions of about 1800 species, scattered in more than one hundred different works and scientific papers. Although such a publication was an indispen- sable preliminary step before any study of the North American diptera could be attempted, it conveyed but a very vague idea of the actual composition of the North American fauna of diptera. It was impossible to ascertain, at that time, how many of the specific names, enumerated in the Catalogue, actually represented different species , and liow many were mere synonyms ; neither was it possible to know, whether the species were placed in the right genera, and even in the right families. In order to give an idea of the extent to which this statement is true, I will quote the genus Trypcfa, wliich (excluding the three species named, but not described by T. W. Harris), contains forty-two ; , n PREFACE. specific names in the old, and sixty-six in the new Catalogue. But, in comparing these two lists, we find that they have only eleven names in common. In other words, of the forty-two so- called species of Trypeta of the old Catalogue, only eleven are adopted now as specific names in that genus ; the other thirty- one names proved , upon investigation , to be either synonyms, or to represent species which had been erroneously placed in the genus Trypeta, or else to be unavailable names , on account of the insufficiency of the descriptions. The ditierence between eleven and sixty-six (the number of species in the new Catalogue), represents therefore the addition made to the knowledge of the genus Trypeta in North America during the interval between the two catalogues. Other genera give similar results. Thirty-two species of BolieJioxms were described previous to 1858; the present list contains fifty-nine; but both lists have only tico specific names in common. Thirty of the earlier descriptions are unrecognizable and therefore useless. The old Catalogue contained 32 names of species of Eristalis, occurring in North America, north of Mexico; of these names only nine figure as species of Eristalis in the present Catalogue, althoigh the de- finition of the genus has not been changed since then. The other names of the old Catalogue are either synonyms (E. dimidiatus, for instance, has been described under six different names), or they belong to other genera, as Hclophilus, Milesia, even XyJota. The genus Tahamts, in the old Catalogue, contains one hundred and two names of species, from North America, north of Mexico among these names only 36 could be adopted; the remainder are either synonyms, or absolutely unavailable, on account of the insufficiency of the descriptions. — These instances will suffice to show that the new Catalogue is, not merely a new edition of the old one, only supplemented by the new species, published between 1858 and 1878; it is a new work, prepared on a diHe- rent plan. The process gone through between two editions of a cata- logue, (the compilatory and the critical edition), consists in form- ing collections, in determining them from existing descriptions, and thus making out the synonymies, and then working up each PREFACE. VII faniil}- in monographs. It will be a long time of, course, before this last stage is reached in all the families of North American diptera, and for this reason, this new Catalogue, which represents the achial state of our knowledge of these diptera, is not entirely homogeneous; a portion of it only is synonymical and critical, and the rest is still a mere list of names, a compilation. The Catalogue may, in this respect, be divided into three groups of families , representing three stages of our knowledge of the species enumerated: 1. The families of the first group have been worked out in monographs, containing comparative descriptions of all -the species (as far of course, as represented in the collections), with analytical tables, or else with figures, to facilitate identification. Such families are the Boliclwpodklae , Ortalidae and Trypetklae (monographed by Dr. Loew) ; the Tiimlidae hrevij^aljoi and Tahanklac (monographed by myself). The beginning of a similar work was made by Mr. Loew for the Ephydrinidae and Sciomy- zklac and by me for the genus Syrp>lius. 2. In the families of the second group , collections have been formed, a certain number of earlier descriptions have been identified and synonymies made out; many new species were described; but a monographic treatment is still wanting. Such families are the Asilidae (with the exception of the section Astlina) , the Bomhylklae, Syrphklae, T'qndidae longipcdpi] also the Enipidac, M'tdaidae, Cyrtklae, Bihionidac, Mycctopliilklae and a number of the smaller families among the Miisckkie acalypterac. 3. In the families of the third group, collections have been formed, but they are, for tlie most part, not named. The Catalogue, in such families, is a mere compilation of references to descriptions by earlier writers. Such families are : the Cidicidae, Chironomidae, Conopidae, the whole group of Muscidae ccdypterae and the section AsiVvna. Collection of type-specimens. A difference between the old and the new Catalogue, perhaps more important than that already explained, consists in the fact, that the majority of the species ! VIII PREFACE. enumerated in the new Catalogue, are represented in a collecfion. The collection of diptera of the Museum of Comparative Zoology in Cambridge , Mass. , contains •what may be called the typical specimens of this Catalogue, that is the types of the descriptions published by Mr. Loew and by myself, as well as the species identified by him or by me, from earlier descriptions. That collection thus contains a little over 2000 named and described species of diptera from Korth Ameiica*;, north of Mexico, besides a considerable accumulation of unnamed and undescribed materials. In that collection the american dipterologist now possesses an advantage not shared by his European colleagues, and that is, of having very nearly all the typical specimens, necessary for his work, collected in the same spot. It is highly desirable that this advantage should, as far as possible, be maintained, and that describers of new species should deposit their types in the same Museum, which offers the best guarantees of their permanent preservation. Sixty years ago , Wiedemann (in the fiirst chapter of his Magazin fur Zoologie), foreseeing the future difficulties of dipterology, suggested the formation of a central, or as he called it, normal Museum, in some European city, to contain types of all the described species; no new species were to be published, without previous comparison in that Museum. May the Museum in Cambridge realize that idea for America Literature. The literary references, which I give in the notes, are not meant to be a complete index of dipterological literature, but merely a guide to beginners, who might be easily deterred by the preliminary work to be gone through, before attempting the study of any family. Those who intend to go deeper into the subject will have to form a more complete index for themselves , by looking over the yearly entomological Eecords**), as well as the works in the li])raries. That the majority of the papers quoted by me are those of Dr. Loew, arises from the fact that for the last 30 years he was the prin- *) These species are marked with a star in the Catalogue. **) A yearly Record on tlie progress of entomology is published in Germany since 163^!, in Wiegmanii's Arcbiv fur Zoologie. This PREFACi;. IX cipal dipterological writer in Europe and that tlie study of his paiiers cauuot enough be recommended. System. The systematic distribution of the diptera and the natural affinities of some of the larger and smaller groups, are still matters of uncertainty. I have preserved, with slight modi- iications , the arrangement adopted by the most recent writers. It has the advantage of alapting, as much as possible, the division in Oiihorhaplia and Cyclorhaplia, to the sequence of the families , as found in Mcigen and other early writers. The Xylophagidae , Stratiomyidae , Coenomyidae , Acanthomeridae, Tabanidae and Leptidae seem to form a natural group, within which it is impossible to bring about a satisfactory linear ar- rangement.