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LRAT ~ ily, i f ‘ i D 5 = { \ . ‘ 4 2 . rt 4 ‘ * Bee SER Pere ef ere AT : a, Ai = DAS sy ta f : ad “ Pre “ ¢ a Pear hea ee ae ; is qo rs Ys Oy eee ee = . / ge : : a , ie ~ ae - 2 . $ dm Xn . “> a * Oy 7 = > 4 Sr : ot A = Sb - ’ - > . a SMITHSONIAN MISCELLANEOUS COLLECTIONS. 5 aa vp MONOGRAPHS OF THE ea PT ER A NORTH AMERICA. PREPARED FOR THE SMITHSONIAN INSTITUTION BY H. LOEW. PART II. EDITED BY R. OSTEN SACKEN. EE ee WASHINGTON: SMITHSONIAN INSTITUTION. JANUARY, 1864. peak PES eee aN ~~ i Pape ce a ASS Sins NET Pees : cd alle Acetone, 3 ee en sen r ‘ - oo SMITHSONIAN MISCELLANEOUS COLLECTIONS. 171 ——______ MONOGRAPHS OF THE oe or FoR OA NORTH AMERICA. - PREPARED FOR THE SMITHSONIAN INSTITUTION BY Hee, OLR W PART Ii. EDITED BY R. OSTEN SACKEN. 1 J re Foe x @ / ee / i Y A) Hf rem “ t ali [SS - vy) / > BAN £2 a ae eo a Dev A OT RA, oT P Ar = —— > Ji ————} a Ay e \ WASHINGTON: SMITHSONIAN INSTITUTION. ‘JANUARY, 1864, 21220% ADVERTISEMENT. THE present publication is the second part of a work on North American Diptera in process of preparation by Dr. H. Loew, of Meseritz, Prussia, undertaken at the especial request of the Smithsonian Institution. The materials have been derived prin- cipally from the collection of Baron R. Osten Sacken, Consul- General of Russia in New York, kindly intrusted to the author for examination. The work will appear in monographs of genera and families, sufficient materials being on hand for illustrating particular groups only, without relation to their systematic sequence. The Institution is under obligations to Baron Osten Sader for superintending the translation of the work from the German manu- script, and editing it, as well as for correcting the proof-sheets. | JOSEPH HENRY, Secretary S. I. SMITHSONIAN INSTITUTION, WASHINGTON, January, 1864. PHILADELPHIA: COLLINS, PRINTER, PREFACE. In the present work I have attempted to give a Monograph of the North American Dolichopodide. The geographical area em- braced in it, as well as in my former Monographs on North Ameri- can Diptera, is the same which has been adopted in Baron Osten- Sacken’s Catalogue, comprising Mexico and Cuba. I readily acknowledge that by adopting such a wide area for the North American fauna, we introduce many species which, properly speaking, belong to a more southern fauna. But I was induced to adopt this course as much by the circumstance that I possessed many interesting species from Mexico and Cuba, as by the advan- tage of conforming to the plan of the Catalogue of Osten-Sacken, and thus affording a general view of the fauna of a larger extent of country. As the order of Diptera is remarkable for the wide geographical range of the species, and as, for this reason, the limitation of local faunas is more indefinite here than in most other orders, the adoption of this somewhat arbitrary limitation of the North American entomological area cannot present any- thing objectionable. | For the greatest part of the materials on which my work is based, I am indebted to the liberal and disinterested assistance of my esteemed friend Baron Osten-Sacken. Some very interesting species were communicated to me by Mr. Le Baron, of Illinois. The greater number of the species from Sitka was collected by Mr. Sahlberg, and communicated to me for description by Pro- fessor Maeklin in Helsingfors; some species of the same region’ are in the Museum of Berlin, and were obtained, if I am not mistaken, also from Mr. Sahlberg. The study of the types of Wiedemann’s Collection, very liberally lent to me for examination ( iii ) iv PREFACE. by the Directors of the Hofnaturalien Kabinet in Vienna, afforded me information of the most valuable character. Although the materials thus put at my disposal can be called abundant, they did not by far reach the extent which I could desire for the preparation of such a monograph. I hope, how- ever, that new supplies will enable me soon to attempt a renewed and more thorough work on the same subject. I have to thank most cordially all those who have contributed by their collections towards the completion of this monograph, and at the same time I earnestly request all North American collectors who take any interest in the order of Diptera to favot me by similar communica- tions. They can reach me either through the medium of the Smithsonian Institution or through Baron Osten-Sacken. With regard to the systematic distribution, I have continued to build upon the foundation first laid by Mr. Haliday in his admira- ble paper on Dolichopodidx, contained in Walker’s Diptera Britannica, and later developed by me in the seventh part of my ‘“‘ Neue Beitraege.’’ To the genera, adopted and defined in those papers, I have added afterwards the gener& Plagioneurus and Lyroneurus, based upon North American species. (Conf. Wien. Entom. Monatsschr. 1857, p. 37.) In the eighth fascicle of my “‘ Neue Beitraege,’”’ which was a prodrome to the present work, I have further added the genera Pelastoneurus and Diostracus ; the first embraces some species which formed previously a sharply limited and well characterized group within the genus Gymnop- ternus; the latter was established for a species which, by its general habitus, reminds equally of Thinophilus and Aphrosylus, but is distinguished from both by the presence of distinct hairs on the upper side of the first joint of the antenne. In the present publication I have added the new genus Paraciius, which combines the neuration of the wings of Pelastoneurus with some characters of Gymnopternus and at the same time is too distinct from the species of the latter genus, to remain united with it. Thus the number of genera, the usefulness or necessity of which I at present recognize, amounts to forty-three. After a general introduction, I give a table for their determination, and then cha- racterize them in detail at the proper place. It will hardly be necessary for me here to attempt to correct the misapprehension PREFACE. Vv that the characters used for the construction of the table are at the same time the most important generic characters; far from such being the case, I have, but only in a few rare instances, tried to facilitate the discrimination of genera by preferring to use charac- ters applicable only to North American species (for instance in the separation of Gymnopternus from the genera immediately following it). The merit of the adopted distribution in genera has been tested and proved by the circumstance, that all the newly discovered species very easily found their proper place in it. Of course, all the genera cannot be considered as equally well established. Above all others, the distribution of the smaller species, for the most part neglected by collectors, as well as difficult to examine, still offers many obscure points. ‘This is especially meant for the proper separation of the genera Chrysotus and Diaphorus. To escape the difficulty of defining the proper position of some North American species, showing the characters of both genera, I have been obliged to draw the line between the two in a somewhat different manner. ‘The relation of the genus Hercostomus to Gymnopternus is likewise not very clear. A continued study of the structure of the known species and the discovery of new ones, will gradually remove this uncertainty and develop the systematic arrangement, so as to keep pace with such an increase of know- ledge. I think, however, that I can give in general the positive assurance, that the location of the species described by me is a natural and not a forced one; the only exception is Synarthrus barbatus, in which the thumb-like projection of the second anten- nal joint upon the inside of the third is much smaller than in the other species of this genus. I possess this species only in a single, not well preserved specimen. As it can hardly be looked for in any other genus but this, I have deemed it more expedient to locate it provisionally here, than to found upon it a new, perhaps not justifiable genus. I have taken pains to elucidate conscientiously the rather con- siderable number of species published by former authors. Un- fortunately, most of these species were described without any > regard to the most essential generic and specific characters, so that only in a very few cases have I been able to identify them. I have preferred not to use specific names the identification of which vi PREFACE. was not quite certain, as this would only have increased the con- fusion. If the identity of one or the other of the species published by me, with a previously described one, should be satisfactorily proved, I will always be ready to grant to the older name the priority over mine. H. LOEW. MeseEriITz, July 1, 1862. ReMARKS.—I have a few words to add respecting the translation of this work, which was done under my care. The terminology used has throughout been that adopted in the first volume of these ‘‘ Monographs.” The term antennal bristle alone has been replaced by the shorter one, arista, used by English writers. It will perhaps not be amiss also to explain the sense of the terms fore and hind and their difference from anterior and posterior when applied to the feet or parts of the feet. By fore feet (cox, femora, tibie and tarsi), corresponding to the German vorderste Beine and the Latin pedes antici, is meant the jfirst*pair of feet (or coxe, etc. ). By anterior feet (corresponding to vorderen Beine, pedes anteriores), the two first pairs are to be understood. In this case, however, in order to avoid all possible misunderstanding, Mr. Loew has almost always used the expression “‘the four anterior feet,” which was retained in the translation. The same rule applies to hind (hinterstc, postici) as indicating the last pair, and posterior (hintere, posteriores) meaning the two last pairs. OSTEN SACKEN. Preface Introduction . 2 ‘ Table for the determinatio TABLE OF CONTENTS. VI. ON THE NORTH AMERICAN DOLICHOPODIDA. n of the Genera Table for the systematic arrangement of the Genera Gen. I. 5s HYGROCELEUTHUS . latipes Lw. %.? Gen. II. Douicnoprcs omatI ann ph WwW be Do wp bd be BB eB Se eB oe eS oe BY WonNMNrowvwvomaosnrt on Lh we pore o . gratus lw. % . laticornis Lw. % . . setifer Lw. % . albiciliatus Lw. ? . xanthocnemus,n.s.%.? . tetricus, nov. sp. 4.9 . acuminatus fw. 5.9? . Bavars fw. 5 «. - . pachycnemus Lw. 4.9 . brevipennis Meig. %.? . longimanus Lw. %.9 . . brevimanus Lw. % | . socius Lw. % ; . mundus, nov. sp. %.° . subciliatus, nov. sp. % . splendidus Lw. % . batillifer Lw. %.9 . eudactylus Lw. %.9. 2 sOnSUS ! fw. TP. . tener Lw. F . variabilis Lw. 4.9 . luteipennis Lw. % . ramifer Lw. %-9 PAGE | ily A WV bn eR % % +2 Gen. III. Gymyoprernvs . | - flavus Iw. 5.9. - Subulatus Zw. % - scotias Lw. 4.9 . bifractus Zw. 4.9 . vittatus Dw. : - cuprinus Wied. %.° . . longipennis Lw. %,. - hastatus, nov. sp. - plumipes Scop. 4. . fulvipes Zw. on $-2 i: . sexarticulatus, n. s. 4 - ruficornis Lw. 4 . . scapularis Lw.%.9 - funditor Zw. 4.9 . chrysostomus Lw. % - preustus Zw. % . - comatus Lw. . scoparius Lw. % . discifer Stann. %.9 - lobatus Lw. 4% . setosus Zw. 5 . . incisuralis Lw. 4.9 barbatulus Zw. 5.9 . tristis, nov. sp. 5.9 . . exilis Zw. 4, ( vii > J Vill TABLE OF CONTENTS. PAGE PAGE 7. spectabilis Jw. 9 ~. | 85 Gen. XIL. Diosrracus #7. hii 74 Oe yo. AL DICe PS earn Ors Sei 1. prasinus Zig. 0 eee 9. subdilatatus Zw 5%. 86 10. levigatus Lw. % - 87|Gen. XIII. Anupsius 5 « 2a ID requens ere i es 12) Momnrter: vito. yin . 89|Gen. XIV. ARGYRA : + lee 13. fimbriatus Lw. % Sal chy) . albicans Lw. %.9 Br 3) 14. despicatus Lw. % ai OO) - Nigripes, NOVa.s7) 45) merc oe veatticnlis Wien Nin. sig . albiventris, nov. sp. % 128 1G micnibanbus Lvs O wn oO minute: Tages 128 IWS oeberMeonteuts (Laas G8) GG): . calcitrans Lw. % Pee 30) US opacws mle isi) is aCe . caleeata Iw. 9 . «aoe NGS oolitmwis VEons VON BON Oe . cylindrica, nov.sp. % . 132 20. debilis Lw. %.9 NOT 95 21. crassicauda Lw. §.2 - 95|Gen. XV. Syyrormon . « 133 22. minutus Lw. % . se 23. ventralis Lw. % . CRONE NTaarwb eH Gen. XVI. SYNARTHRUS . . 134 ) 1. palmaris; ney. Sp. 45-9) 730 Gen. IV. Paracuius > - 97 2. cinereiventris Zw. 9 . 137 1. arcuatus Lw. 9 . Sly dO 3. barbatus Lw. % . . 138 2. albonotatus, n.s. %.? 102 Gen. XVII. Systrenus . wag Gen. V. PELASTONEURUS . a OS . longicauda Lw. % . 104 . lugubris Lw. @ . qulOe : Gen, XVIL. Ruwais eS 3. letus Lw. %, eM ee uO 4 5 1. Iugubre LO. . 141 . vagans Lw. %,.9 Ol | Boats iba aos Gen. XIX. XIPHANDRIUM a Ash Gen. VI. TAcHYTRECHUS . 109 COR! ee Oe ae “ee 1. moechus Lw. %.9 . 110 1. ue eam pe lw. %.Q9 . 144 2. vorax Lw. %.9 . Pte 2: unlenneoeses 1. fe) oS 3. angustipennis Zw. % . 113 3. eel eee Tw. © - 146 4. rotundiceps Zw. % .. 146 Gen. VII. OrtTHOCHILE . SAA Gen. XXI. SmiLiotus é Ag (217 Gen. VIII. SyBistRomMA . essa BSL) Gen. XXII. APHROSYLUS . LES Gen. IX. Hercostomus . Se LELuS) 1. unicolor, nov. sp. % . 117/|Gen. XXII. Tuivopuitus . 148 Gen. X. HyPoPHYLLUS . - 118) Gen. XXIV. Propzs PONT aes! 6S) Gen. XI. HALTERICERUS . - 119|Gen. XXV. Nemaroproctus . 150 TABLE OF Gen. XXVI. LevcosroLa js 1. cingulata Lw. % Gen. XXVII. Evrarsvs . 1. eques, nov. sp. % Gen. XXVIII. Diarnorvs - opacus lw. % .. . . mundus Lw. $.9 . Spectabilis Zw. % 3 . sodalis Lw. 4.9 - lamellatus, nov. sp. % - leucostomus Iw. 4.9 interruptus lw. % . TAO RP WD Gen. XXIX. LyronEvRtS 1. cerulescens Lu. % Gen. XXX. CuRysotTus - cornutus, nov. sp. § . . longimanus Lw. % . validus Lw. 9 . obliquus Lw. %.9 . affinis Iw. 5.9 . Se wividus, HOV. sp. 5. . costalis Lw. 4.9 ° - Ssubcostatus, nov. sp. % . discolor Lw. 4.9 . auratus Iw. 9 . : . pallipes Lw. %.9 ; . picticornis, nov. sp. % eoMmaI naanh WD Ee a be oO Gen. XXXI. TevcHopHorvus Gen. XXXII. Sympycyvs 1. tertianus, nov. sp. $.9 2. frontalis Lw. 4.9 3. lineatus Lw. %. 9 4. nodatus Zw. %.? . Gen. XXXIII. CAmpPsicNEMUs . 1. hirtipes Iw. %.9 2. claudicans, n. s. $.9 Gen. XXXIV. PLAGIONEURUS . 1. univittatus Lw. 2 PAGE 151 152 153 154 156 160 161 162 163 165 166 168 169 170 171 174 175 175 176 178 178 179 181 182 183 183 184 185 185 187 188 189 191 193 193 194 196 196 CONTENTS. Gen. XXXV. LIANCALUS . ° 1. genualis Lw. 4.9 Gen. XXXVI. ScELLUs . exustus Walk. 4.9 . spinimanus Zeit. 4.9 . avidus, nov. sp. 4 . . filifer, nov. sp. % ° m OO be Gen. XXXVII. Hypropnorvs . 1. innotatus, nov. sp. §. 2. piratalw. Q . ° 3. parvus Iw. 5 - Gen. XXXVIII. AcHaxcus Gen. XXXIX. MEDETERUS 1. nigripes Zw. 9 . 2. veles Lw. % Gen. XL. CHRYSOTIMUS . 1. pusio Lw. 2 ° 2. delicatus Lw. Q . Gen. XLI. XANTHOCHLORUS 1. helvinus Zw. Q . ° Gen. XLII. Saucrorvus . dimidiatus Lw. % . rubellus Zw. Q . F . superbiens Iw. 4.9 . . tenuis, nov. sp. ? A mw hb Gen. XLIII. Psmuopus . : diffusus Wied. %.9 . guttula Wied. %.9 . . dimidiatus Lw. % : . sipho Say, %.9 ‘ . scaber fw. % : . patibulatus Say, $.9. . melampus Lw. %.? . pilosus Zw. 5 ’ . jucundus Lw. 4.9 IAS TP wh eH ix PAGE 198 199 200 ‘202 204 207 209 211 212 214 216 217 218 218 219 220 221 222 223 224 224 225 226 227 228 229 235 237 246 247 250 251 253 256 258 x TABLE OF CONTENTS. PAGE PAGE 8. ciliatus Zw. > pn 2G8) 15. scintillans Zw. §.Q9 . 273 9. comatus Jw. %.9 . 262 16. pallens Wied. §.Q2 .- 275 10. chrysoprasiusWk.%.9 265 17. variegatus Lw. 2 . 278 11. scobinator Zw. %.Q9 . 268 18. bicolor 220.090 ie - 280 - 12. caudatulus Lw. % S740 19. psittacinus Zw. %.Q9. 281 13. calearatus Lw. % Bil 20. tener Lw. 5.2 - . 284 14. inermis lw. % . Ne PAIR 21. filipes Zw. § . . 286 APPENDIX. Species described by previous authors, and not contained in this Monograph . : . . : ° . : . - (ag Fabricius, Systema Entomologie 289 | Macquart, Diptéres Exotiques . 297 Musca longicornis . Sil 21S) Psilopus sipho : Pep ashi radians . - 298 Fabricius, Entomologia systema- Chrysotus viridifemora . 298 HIGER : é ay ASS) Dolichopus heteroneurus. 299 Musca longicornis . 5 ais) Walker, Insecta Saundersiana . 300 Psilopus lepidus Axa of Came Medeterus exustus 9 . 300 viridiflos 9 . 301 Dolichopus bifrons 2 wv BOE consors Q . 302 contingens 9. 302 hebes 2 - 302 ineptus @ . 303 maculipes 9 . 303 pulcher$.Q2. 304 varius 2 - 304 Say, Jour. Acad. Nat. Se., Phil. 289 Dolichopus unifasciatus . 289 obscurus ay 200 femoratus . 290 Chrysotus nubilus . 5 aE concinnarius . 291 abdominalis . 291 Medeterus lateralis . ozo punctipennis . 292 Dolichopus abdominalis . 292 Wiedemann, Aussereurop. Zwei- Walker, List of Dipt. Brit. Mus. 304 fliigel. Insecten - «. 292 Psilopus delicatus 9 . 304 Psilopus macula. 2 292 gemmifer 7 « 305 Sayi . : 290 chrysoprasi e NSGor longicornis - 294 suavium . - 306 caudatus . . 294 amatus §.? . 306 virgo : - Ad inficitus . - 3807 femoratus . yr 2405) nigrofemoratus . 307 mundus -. - 296 albicoxa §.Q9 . 307 Dolichopus obscurus Say. 296 | Chrysotus incertus 5 . 308 Porphyrops pilosicornis . . 30s Macquart, Suites a Buffon, Dip- Medeterus glaber . 5 « BOS teres. ; ‘ Set ONG: chrysologus 9 , oue Psilopus radians. 51) eA alboflorens 9 - 810 ‘ TABLE OF CONTENTS. xi PAGE PAGE Dolichopus affinis }.9 . - 310] Dolichopus terminatus 9 i316 cuprinus Wied. . 311 sequax . a ol lamellipes %.9 . 311 soccatus ‘ . di ciliatus 4.9 Pe cs remotus : spies, adjacens 9 . « ele irrasus . ° Sols coercens % . - 312/Orthochile derempta . . 318 finitus. 6. ela distractus . - 313| Walker, Trans. Entom. Soc. . 319 discesus 9 . . 314 Psilopus ungulivena o) okg contiguus 4, . 314 solidus : . 319 exclusus? . ,. 314 peractus . Peal confinis Q . = oko hereticus . . 320 conterminus 4 . 315 permodicus . 320 separatus 9? ren SUPPLEMENT. I. General remarks on the Dolichopodidez of North America . anor II. Description of some Species communicated after the volume had gone through the press. : . ° - SRE - 323 Gen. II. DoxicHopus ; - 323 26. coxalis Zu. 5 . A eBy: 43. doryeerus Lw. % . 326 27. meniscus Lw.%.9 . 336 44. splendidulus lw. % . 327 28. humilis Lw. 4.9 - 336 45. palestricus Lw. %.9 . 328 29. exiguus Iw. 9 . - 337 ' 46. melanocerus Zw. %.2 330 47. quadrilamellatus Lw. Gen. V. PELASTONEURUS . - 337 %-@ ° : - 331 6. lamellatus Lw. 9 - 338 7. abbreviatus Zw. 4.2 338 Gen. III. GymMNoPTERNDS - 332 8. alternans Lw. 9 . - 339 19. politus Zw. 4.9 . 334 24. pusillus Zw. Q . . 334/Gen. VI. PorPpHyrops . . 340 27. chalecochrus Iw. %.Q 335 5. longipes Zw. % . . 340 EXPLANATION OF THE PLATES A : ° cs ‘ 5 bs aad REMARKS ON THE GENERIC CHARACTERS EXPLANATORY TO THE PLATES . 345 INDEX : s 5 a, ee 2 E z wt ope iy 4 ee Hatarute tie i ae Vl a0 bed Oe Bape OF NORTH AMERICA. PART If. Wal. ON THE NORTH AMERICAN DOLICHOPODIDAE. INTRODUCTION. Tue Dolichopodidx are among those families of diptera which show but so few points of relationship to others that it is impos- sible to name any family of a particular affinity to them. A superficial glance, it is true, seems to point out the Yphydrinide and the genera of the Tachydromide in the vicinity of Clinocera as the nearest to the Dolichopodidx; but a closer examination will show that, instead of a true relationship, there are merely some points of external analogy between them, points common | to most insects (and not only diptera) preferring to live in the vicinity of water. The want of a true relationship becomes immediately apparent when any portion of their inner or outer organization is submitted to a comparative scrutiny. The neura- tion of the wings of the Dolichopodide alone is so peculiar that it is sufficient in itself to distinguish this family not only from the Ephydrinide and the above-mentioned group of Tachydro- midz, but also from all other families of the order. This neura- tion, together with the brilliant-green color of the greater part of the species, renders the Dolichopodide one of the most easily recognizable families of diptera. The peculiarities of the neuration, which is shaped in general 1 2 DIPTERA OF NORTH AMERICA. [PART II. according to the type of the Diptera acalyptera (compare Mono- graphs, etc., I, page xxiv, fig. 1), are the following in this family: The costal vein extends as far as the tip of the-fourth longitudinal vein; the auxiliary vein does not run towards. the costa, but to- wards the first longitudinal vein, stopping quite far from its tip, and either coalescing entirely with it or disappearing without having joined it. The third longitudinal vein emerges from the second not far from its root, and both veins form at this place a more or less knot-shaped swelling; the small cross-vein (often quite obsolete) is at, or close by, this swelling, so that the first basal cell is unusually short; the discoidal cell, much narrowed towards its base, is coalescent with the anterior of the two small basal cells in consequence of the absence of the vein separating them. The posterior small basal cell (the so-called anal cell) is small and rounded at the end. The sixth longitudinal vein does not generally reach the border of the wing; sometimes it is en- tirely wanting, and in this case the anal cell becomes indistinct. The alar appendage (alula) is so narrow that it may be considered as wanting. é Although all Dolichopodide agree in the above-described pe- euliarities of neuration, still this same neuration affords very good and abundant characters for the distinction of the genera and the species; the length and direction of the first longitudinal vein vary considerably, the position of the posterior transverse vein also; the most striking characters, however, are taken from the structure of the last portion of the fourth longitudinal vein, which is subject to considerable variation, being sometimes parallel to the third longitudinal vein, sometimes more or lesS convergent with it, sometimes straight, often curved or bent abruptly in the middle, or even broken. In the latter case, the angle formed by the strong flexure or fracture sometimes bears a rudiment of a branch-vein, which in some cases (as in most Pstlopus) is long enough to make the vein appear forked. For the purpose of distinguishing the Dolichopodide from the other families of diptera the characters taken from the neuration are sufficient, and it is superfluous to have recourse to others taken from the rest of the body. It is different, however, if we intend to establish the natural character of this family. I will confine myself here to characters taken from the external organi- zation, and as to the internal one, I will merely notice in passing INTRODUCTION. 33 that, in accordance with the external structure, it forms a striking contrast with the organization of all the other dipterous families. The head of the Dolichopodide in general is more or less he- mispherical. Its sides are occupied by the large, ovate, hairy eyes (naked only in Medeterus), which usually reach so far down that in most genera there are no cheeks (genx) at all, and that on the under side of the head, between the eyes, there is just space enough for the large opening of the mouth, which, in some spe- cies, even encroaches upon a considerable portion of the occipital side of the head. The usually rather broad front bears three ocelli, protected by strong bristles, and several bristles in both corners of the vertex; the remainder of its surface has no bristles. The frontal fissure and lunule* are indistinct. The antenne are three-jointed, of very different structure in different genera, nay even often in the sexes of the same species; the second joint is sometimes rudimentary. The arista is two-jointed, seldom alto- gether bare, generally with a very short pubescence, more seldom fringed with longer hairs or even plumose; its dorsal or apical position affords very constant distinctions between different genc- ta; its length and the other characters belonging to it differ sometimes even in the two sexes of the same species. The face is usually vertical and smooth; it has often on its inferior third an elevated transverse swelling, or at least, on each side, near the orbit of the eye, a nodule-like elevation; seldom does the face reach down to the inferior angle of the eye; it is always without any bristles, although sometimes it is hairy; its lower edge is rather sharp, and does not coalesce with the border of the mouth ; from under this edge project the single-jointed palpi, incumbent upon the proboscis (except in Aphrosylus, where they hang down on its sides); they are usually scale-shaped, more seldom lancet- shaped (for instance, in Orthochile) or round, pallet-shaped (in Diostracus); in the females they are usually considerably larger than in the males; sometimes however (in Diostracus), the oppo- site is to be found. The proboscis is generally short and (with the exception of Aphrosylus and Orthochile) stout; its opening is wide, more or less surrounded by the protuberant suctorial flaps, which, by clap- * For the explanation of these terms, compare Monographs, Vol. I, p. xiie —0O. S$. 4 DIPTERA OF NORTH AMERICA. [PART II. ping together, shut the opening ; the species of the genera with a large proboscis, especially their females, can altogether engulf small insects within their proboscis, as if they swallowed them, whereas they only suck them out and throw the remainder away. The horny parts of the mouth are short. The stout labrum has on its lateral edge, which is bent downwards, several deep incisions, thus forming strong teeth. The tongue is longer than the labrum, and lies under it without being encased in it. The upper side of the thorax is convex, with bristles inserted in rows, between which there are more or less numerous short hairs ; in some genera there is a flat, somewhat concave declivity before the scutellum. Prothorax and mesothorax are very coalescent ; no distinct collare is perceptible, and the humeral callosities are not sharply limited; of the ordinary transverse suture only the begin- ning is indicated on both sides by a large, more or less triangular impression. Scutellum with two, four, or six strong bristles; more- over, its surface is sometimes hairy. The elongated prothoracic stigma is closed. Immediately above the basis of the fore coxe there is a strong bristle, seldom several. The metathoracic stigma is unusually small. The epimera of the metathorax have a very large development; they embrace often the basis of the abdomen from the side to a considerable breadth, and extend as a narrow stripe along the basis of its upper side. The abdomen of the female has seven segments, the last two of which are generally very narrow and contracted under the pre- ceding ones, so that only five segments appear on the outside; the seventh segment, in the female, bears on its end two small lamelle connected with it by an articulation and fringed with hairs; above them there is, in many species, a fan-shaped row of short, stiff, thorn-like bristles; in other species the number of these thorns is reduced to four or two; sometimes they are altogether wanting ; the latter is especially the case with those species which prefer dry localities, or also those, the hind part of the thorax of which has a flat usually concave declivity; this difference in the structure of the ovipositor has certainly some relation to the difference of the locality where the eggs are deposited; it is possible that a complete fan of thorn-like bristles constitutes a peculiarity of the species the larvee of which live under ground, whereas it is wanting when the eggs are laid in decayed wood. The abdomen of the male can also be considered as consisting INTRODUCTION. 5 of seven segments, if the hypopygium be considered as a single’ segment; of the sixth segment only the upper half is distinctly developed, but it is much narrower and shorter than the surface of the immediately preceding segments. "When this sixth segment is concealed under the upper half of the fifth, or when it is strik- ingly different by its coloring from the preceding segments and resembles in this respect the seventh, then the male abdomen appears only five-jointed. The seventh segment consists of the proportionally large hypopygium, the structure of which, near its basis, is not quite symmetrical. It consists of a rather stalk-like basal part and of a club-shaped posterior part; the stalk-like part is often very much abbreviated, and then not easily perceptible ; the club-shaped part is movable towards it; the junction of both parts lies always above, on the left hand side of the club-shaped portion. The hypopygium is more or less inflected under the abdomen, sometimes imbedded in an excavation of the venter proportionate to its size. At the tip of the inflected hypopygium, below, are inserted, by means of articulations, three pairs of appendages of manifold structure. The outer pair of these appendages is gene- rally larger than the two others, and must be considered as organs of a great irritability, as the roots of the hairs on their inside are connected with nerves. The basis of this pair is linked to the hypopygium by a free‘articulation. The two other pairs, attached by a less free articulation, can be considered as organs for the purpose of seizing, clutching; they lie within the former pair and are not seldom of a very complicated structure. Sometimes one or the other of these pairs exceeds in length the outer pair.. In- nermost between them, coinciding with the middle line of the clutching apparatus, a single appendage is inserted, which also appears to be linked at its basis. On the upper side of the hypo- pygium, which is the side turned towards the abdomen, there are two more appendages, usually in the shape of a gutter; they have no link at their insertion. Above this gutter, or, more seldom, within it, is another appendage, in the shape of a spike, which in some cases is somewhat button-shaped at the tip; it is pierced lengthwise by a channel, and incloses more or less completely the penis, which protrudes considerably during the act of copulation. This organization is most distinctly developed in the genus Doli- chopus, whereas it is more difficult to observe in the genera with 4 6 DIPTERA OF NORTH AMERICA. [PART IL. ‘a small and imbedded hypopygium. In some genera the one or the other of the paired organs are so small as to escape notice. A further and more thorough investigation has as yet to show whe- ther in some genera, and this seems, for instance, to be the case with Hypophyllus, a still larger number of appendages does not occur, and whether in general the organization of all the genera can be reduced to the common type, described above. Of the first abdominal segment often only the upper half is perceptible in the male and the female; this is especially the case in those genera in which the metathoracic epimera cover a con- siderable breadth of the basis of the abdomen; in other genera the inferior half of the segment is much shortened, and in a few cases only equal in length to the upper half. In several genera the lateral margin of the second and of the following segments shows deep punctures, arranged in a longitudinal row. The fore cox, which are somewhat distant from the middle ones and placed much higher than those, are also longer, and reach as far as about the middle of the latter. The feet are in general slender, the hind pair generally longer and stouter than the others; the femora are often rather strong. Besides short hairs, the feet bear usually a number of stiff bristles, especially the tibize. The pulvilli are only of moderate size; the empodium is linear and always distinct; the claws (wngues) are plain and small. We have already explained above what is necessary for the understanding of the very characteristic neuration of the wings. The surface of the latter is microscopically hairy upon its whole extent. The tegule are ciliated with bristle-like hairs, and some smaller ones besides; they are simple, as the inferior duplication is wanting or only apparent as a narrow membranous stripe ex- tending towards the corner of the scutellum. The sexes of the same species show, besides the difference in structure of the genital organs, other important differences in their organization; the coloring of the same parts of the body is often different. Here, as in many other families, it is in the male sex that these peculiarities assume the character of variously modified ornaments, and it seems impossible to trace any relation between them and the sexual functions or the sustenance of the male. The only exception in this respect is afforded by the considerable dif- ference in the structure of the parts of the mouth, which is much more developed in the females, in accordance with their greater INTRODUCTION. i need of food, and consequently their more predaceous habits. The plastic differences distinguishing the male sex from the other may be defined as follows: The eyes of the male are generally some- what larger, the face and sometimes also the front narrower; the contiguity of the eyes in the male is not frequent; still it takes place in some Diaphorus above the antenne, and in some Chry- sotus below them. The third joint of the antenne of the male is usually somewhat longer, sometimes much longer than in the female; likewise the antennal arista of the male is often much prolonged, sometimes extended into a club or button at the tip or enlarged in the shape of a lamel, whereas in the female the arista is much shorter and quite plain. The feet of the females are, almost without exception, plain; those of the male often differ consider- ably from them, and have various handsome ornaments, principally on the fore and middle tibiz, and the fore and middle tarsi; the femora as well as the hind tibie and tarsi very seldom show any- thing but a plain structure. To these differences in the structure of the feet must be added those derived from the hairs and bristles which they bear; in the female these are usually more sparse, shorter, and coarser; in the male, closer, more delicate, and longer ; sometimes also they assume in this sex some peculiar modified structure. Even the ungues of the male are sometimes of a pecu- liar irregular shape; the pulvilli are in some cases (as in Diapho- rus) larger in the male than in the female. The wings of the male often differ from those of the female in the outline and the neura- tion, those of the latter being in general more plain, and repro- ducing in their neuration the characters common to the genus; whereas the wings of the male show in both respects more specific peculiarities. These consist usually in characteristic sinuses of the posterior margin and in a stronger sweep of flexure of the longitudinal veins; sometimes the anterior margin also shows a peculiar curve in its outline, or a local thickening, or an elegant fringe of hairs, all of which do not exist in the female. The hairiness of the eyes, as well as the hairs and bristles on the other parts of the body, is frequently more dense, often con- siderably longer in the male than in the female. The very minute . and dense tomentum with a silvery reflection, which adorns the abdomen and the thorax in most species of Argyra, also forms spots on the thorax of some other genera (as Pelastoneurus) and, in the species of most genera, is perceptible at least on the lateral 8 DIPTERA OF NORTH AMERICA. [PART II. margins of the abdomen, is likewise generally more extended and much denser in the males than in the females. The sexual differences in the coloring may be described as fol- lows: The eyes of the male are frequently of a different color than those of the female, particularly so, for instance, in the genus Diaphorus. The enlargement of the antennal arista in the male often has a different coloring, usually white. The eolor of the face in the male is generally of a purer, often a brighter shade. In _ Imany species, the halteres of both sexes are colored differently— for instance, in an entire group of species of Psilopus, they are black in the male and yellow in the female. Even the cilia of the tegulee hae in a few instances (as in some species of Dolichopus) a different coloring in the two sexes. Differences in the coloring of the feet are not rare; they are especially striking in the genus Psilopus, some species of which have altogether yellow feet in the female, and black femora in the male; in others, the pale coloring of the feet is more extended in the female than in the male. The ornaments of the feet, peculiar to the males, also differ in their coloring from the corresponding parts of the feet of the other sex, being usually black, sometimes whitish, or with a handsome silvery reflection. Even without displaying any peculiarity of structure, the feet of the male have sometimes white or silvery spots, which are wanting in the female. ‘The wings are in some cases pictured in the male and not in the female. Such are some species of Dolichopus, Tachytrechus and Systenus, the males of which have a black or white spot at the tip of the wing or in its proximity, whereas the female does not show any trace of such a spot. The same peculiarity occurs also in some other genera. These, often so conspicuous differences between the sexes of the same species, sometimes render the recognition of their specific identity somewhat difficult. In order to proceed in such cases with some degree of certainty, it is necessary to pay a particular attention to those characters which are usually common to both sexes. The most reliable characters of this kind are: the hairs on the antenne, especially on the first joint; the shape of the second antennal joint; the position of the arista; the color of the cilia on the inferior orbit; that of the cilia of the tegule, notwith- standing some exceptional cases of its diversity in the two sexes. In most genera, to these characters may be added the coloring of the feet and of ‘the halteres as well as the neuration of the wings. INTRODUCTION. 9 The first two of these characters will hardly ever mislead, if it is borne in mind that they have no value in the genus Psilopus, especially in the subdivision with black cilia on the tegule. As to the latter character (neuration) it should be remembered that the peculiarities strikingly developed in the males as specific marks are but slightly indicated in the female, and can be perceived only by a very close observation. The habits of the Dolichopodide are, as far as known, generally predaceous. Most of them hunt for smaller diptera or other insects with soft bodies and suck them out. They are usually found in damp places, covered with a rich vegetation ; many are principally found on the leaves of aquatic plants, on stones, partly overflown with water, on dams and near waterfalls; some of them are able to run rapidly over the water even when it is rippled by wind (Hydrophorus); others are fond of salt or brackish waters (Aphrosylus, Thinophilus and some Hydrophorus) ; the species of Medeterus prefer dry situations and are found on stumps of trees, fences, etc., even in very dry and hot weather. Little is as yet known about their mode of transformation. Most species live as larvee under the ground; some are found in the earth collected in hollow, rotten stumps; others (as Systenus) in wood undergoing a process of dry decaying. After all that has been said above, the natural characters of the Dolichopodidz may be put down as follows: Generally metallic green, brisk and restless diptera of small or medium size, preda- tory on other insects and living principally in damp situations ; the male sex are principally distinguished from the females by differences in the structure of the feet; the larve living under ground or in decaying wood. Head hemispherical, eyes large, usually not contiguous in both sexes, hairy, fenced in, along the hind border with a row of bristles or hairs. Front, with bristles on the vertex only, and with three ocelli. Antenne stretched out straight, with a two-jointed arista. Face, without mystacine bristles ; its inferior border not merging into the lateral border of the mouth. Oral opening occupying the whole underside of the head, and often also a considerable portion of its hind plane. . Proboscis short and stout, concealed above by the single-jointed, usually scale-shaped palpi, with a wide opening which can be shut by the protruding suctorial flaps. Labrum short and stout, with coarse tooth-like excisions on the sides; lingua much more slender 10 DIPTERA OF NORTH AMERICA. [PART IL. and somewhat longer. Prothorax and metathorax very coalescent, with rows of bristles; the usual transverse suture indicated only on the sides. Abdomen with seven segments, only five of which are visible on the outside in the female, whereas in the male the sixth segment is generally perceptible, and the seventh consists of the hypopygium, usually inflected under the abdomen and com- posed of two consecutive parts, bearing at the end eight paired and two single appendages. Wings microscopically hairy on their whole surface; auxiliary vein not running towards the anterior margin; anterior basal cell very short; discoidal cell coalescent with the second basal cell; posterior basal cell very small; alula rudimentary; tegule distinct, simple, ciliated with long hairs. % TABLE FOR THE DETERMINATION OF THE GENERA. 11 TABLE FOR THE DETERMINATION OF THE GENERA. 1 { First antennal joint hairy above. 2 First antennal joint glabrous above. 16 2 Hypopygium disengaged. 3 Hypopygium more or less imbedded. 14 9 { First joint of the hind tarsi bristly. os First joint of the hind tarsi not bristly. 5 { Face descending as far as the inferior angle of the eye. 4 Gen. J. HyGrocELEvTHts. | Face not descending as far as the inferior angle of the eye. L Gen. II. DoxicHopus. 5 | Palpi of the male unusually large. Gen. XII. Diosrracvs. Palpi of the male small 6 ( The last portion of the fourth longitudinal vein is parallel, or almost 6 4 so, to the third longitudinal vein. Gen. III. Gymnoprernvs. | The last portion of the fourth longitudinal vein is distinctly convergent towards the third longitudinal vein. f The end of the fourth longitudinal vein is abruptly, or at least steeply deflected anteriorly. 8 The end of the fourth longitudinal vein is only gradually deflected anteriorly. : 9 Arista with the usual pubescence; the end of the fourth longitudinal vein, beyond the angular flexure, runs in a curve. Gen. IV. Paractuivs. Arista short-plumose ; the end of the fourth longitudinal vein, beyond the rounded flexure, runs in a straight line. ~T co Gen. V. PELASTONEURUS. The face reaches down to the inferior corner of the eye. Gen. VI. TAcHYTRECHUS. The face does not reach down to the inferior corner of the eye. 10 Proboscis and palpi very much prolonged. Gen. VII. OrtHocHite. Proboscis and palpi not prolonged. 11 Scutellum hairy. Gen. VIII. Sysisrroma. Scutellum not hairy 12 Hypopygium sessile. Gen. IX. Hercostomos. Hypopygium pedunculated. 13 Second antennal joint of usual shape. Gen. X. Hypopnytuvs. Second antennal joint rudimentary. Gen. XI. HaALreRIcerus, pet — eI bo © 4 (Sy) 12 DIPTERA OF NORTH AMERICA. [PART II. eee of male laterally compressed. Gen. XIII. Anspsivs. Abdomen of the male not compressed. 15 {Second antennal joint of the usual transverse shape. | Gen. XIV. ARGYRA. Second antennal joint with a thumb-like projection over the inside of the third. Gen. XV. Synrormon. Third antennal joint in both sexes, or at least in the male, prolonged, pointed, and with an apical arista. ee 17 Third antennal joint short even in the male, and if it should be somewhat prolonged, then neither pointed nor with an apical, but at the utmost with a subapical arista. 23 Second antennal joint with a thumb-like projection over the inner side of the third. ~ Gen. XVI. SyNARTHRUS. Second antennal joint without a thumb-like projection, transverse. 18 Posterior transverse vein distant from the margin of the wing; palpi jt on 4 lor) ra ~J | 1 | | L ( 18 incumbent. 19 | Posterior transverse vein approximated to the margin of the wing; L palpi hanging down. Gen. XXII. ApHRosyLvs. 19 { Hypopygium pedunculated, free. Gen. XVII. SystEnus. Hypopygium sessile, more or less imbedded. 20 20 { The male abdomen has five segments. Gen. XXI. Smiuiorus. The male abdomen has six segments. 21 Third antennal joint prolonged also in the female. a1 Gen. XVIII. Roapuivm. Third antennal joint of the female not prolonged. 22 {Third antennal joint of the male very much prolonged (small, less 22 hairy species). Gen. XIX. XIPHANDRIUM. Third antennal joint of the male moderately prolonged (larger, more L hairy species). Gen. XX. PoRPHYROPS. 93 | Fourth longitudinal vein forked. Gen. XLIII. Psitopus. Fourth longitudinal vein simple. 24 Upper side of the thorax convex behind. 25 24 Uppe side of the thorax behind with a somewhat concave depres- sion. 40 25 | Fifth longitudinal vein altogether wanting. Gen. XXXVIII. Acwatcovs. Fifth longitudinal vein distinct. 26 ( Distance of the posterior transverse vein from the margin of the wing | equal to its own length or longer. 27 an Distance of the posterior transverse vein to the margin of the wing if shorter than its own length. 38 Gen. XXXIV. PLAGIONEURDS. Posterior transverse vein but little oblique. 28 Hypopygium distinctly bent under the venter. 29 28 i Hypopygium not distinctly bent under the venter or entirely imbed- ded. 30 Posterior transverse vein unusually oblique. ar| TABLE FOR THE DETERMINATION OF THE GENERA. 13 The face of both sexes very broad, not narrowed superiorly. Gen. XXIII. Turinoruiuvs. 244 The face of both sexes rather narrow, somewhat narrowed superiorly. Gen. XXIV. PrEopEs. Outer appendages of the hypopygium long, filiform. s0| Gen. XXV. NEMATOPROCTUS. Outer appendages of the hypopygium not iong, nor filiform. dl Third joint of the male antennz conspicuously large. =| Gen. XXVI. Levcostona. Third joint of the male antenne small. 32 39 | Pulvilli of the male fore tarsi conspicuously enlarged. 33 Pulvilli of the male fore tarsi not, or very slightly, enlarged. 34 33 4 Pulvilli of the male fore tarsi not prolonged. Gen. XXVII. Evrarsvs. Pulvilli of the male fore tarsi prolonged. Gen. AXVIII. Diapnorvs. 34 { Arista altogether or almost altogether apical. 35 Arista dorsal. 36 35 { Wings of considerable size (larger species). Gen. XXIX. LyRonEvRus. Wings of small size (smaller species). Gen. XXX. CuRysoTUs. Feet of the male with isolated, strong, spine-like bristles. 30 Gen. XXXI. TrEvcHoPHoRvS. Feet of the sexes without isolated, strong, spine-like bristles. 37 94 { Face not narrowed above. Gen. XXXII. Sympycnus. UFace considerably narrowed above. Gen. XXXIII. Campsicyemus. - All femora slender, abdominal segments with bristles before the hind | margin. Gen. XXXV. Liancatvs. Fore femora incrassated towards the basis. 39 39 { Fore tibie with long thorns. Gen. XXXVI. Scrtuus. Fore tibie with very short little thorns. Gen. XX XVII. Hypropuorovs. man { Arista apical, or at least subapical. 41 Arista distinctly dorsal. 42 Third and fourth longitudinal veins strongly convergent. a} Gen. XXXIX. MEDETERUS. Third and fourth longitudinal veins parallel. Gen. XL. Curysorimus. 42 { Male abdomen with six distinct segments. Gen. XLI. XANTHOCHLORUS. Male abdomen with five distinct segments. Gen, XLII. Savcrorus. 14 DIPTERA OF NORTH AMERICA. [SPARE ake SYSTEMATIC ARRANGEMENT OF THE GENERA. I. First joint of the antenne with hairs on its upper side. A. Hypopygium disengaged. A. Palpi of the male small. 1. First joint of the hind tarsi bristly. Gen. I. Hygroceleuthus. Gen. Il. Dolichopus. 2. First joint of the hind tarsi not bristly. a. Third and fourth longitudinal veins parallel or sub- parallel. Gen. III. Gymnoptermus. b. Third and fourth longitudinal veins convergent. Gen. IV. Parachlius. Gen. VIIL Sybistroma. Gen. V. Pelastomeurus. Gen. IX. Hercostomus. Gen. VI. Vachytrechus. Gen. X. Mypophylius. Gen. VII. Orthochile. Gen. XI. Haltericerus. B. Palpi of the male conspicuously large. Gen. XII. Diostracus. B. Hypopygium more or less imbedded. Gen. XIII. Amepsius. Gen. XV. Syntormon. Gen. XIV. Argyra. II. First joint of the antenne entirely bare on its upper side. A. Third antennal joint in both sexes, or at least in the male, elon- gated, tapering in a point, with an apical arista. A. Posterior transverse vein distant from the margin of the wing, palpi incumbent. Gen. XVI. Symarthrus. Gen. XIX. Kiphandrium. Gen. XVII. Systerus. Gen. XX. Porphyrops. Gen. XVIII. Rhaphiuma. Gen. XXI. Smiliotus. B. Posterior transverse vein approximated to the margin of the wing; palpi hanging down. Gen. XXII. Aphrosylus. SYSTEMATIC ARRANGEMENT OF THE GENERA. 15 B. Third antennal joint short even in the male, or if somewhat elon- gated, then neither pointed at tip nor with an apical, but, at the utmost, with a subapical arista. Gen. A. Fourth longitudinal vein simple. 1. Upper side of the thorax convex posteriorly. a. Fifth longitudinal vein distinct. a. Distance of the posterior transverse vein from the hind margin of the wing equal to its own length or longer. XXIII. Thinophilus. XXIV. Peodes. XXV. Nematoproctus. Gen. XXVI. Leucestola. XXVIII. Evitarsus. Gen. XXVIII. Diaphorus. Gen. XXIX. Lyromeurus. Gen. XXX. Charysotus. XXXI. Feuchophorus. Gen. XXXII. Sympyecmnus. Gen. XXXII. Campsicnemus. Gen. XXXIV. Plagioneurus. 8. Distance of the posterior transverse vein from the margin of wing shorter than its own length. Gen. XXXV. Liancalus. Gen . XXXVI. Scellus. Gen. XXXVII. Hydrophorus. b. Fifth longitudinal vein altogether wanting. Gen. XXXVIII. Achalkcus. ae Upper side of the thorax posteriorly with a flat, somewhat concave, declivity. . XXXIX. Medeterus. XL. Chrysotimaus. Gen. XLI. Kanthochlorus. Gen. XLII. Saucropus. B. Fourth longitudinal vein forked. . XLIII. Psilopus. aye S ee Set venti vraag ay" Si BS Py Ae Lan peered pede R et tg "S Uns ee m4 Wie ae HYGROCELEUTHUS. LT Gen. l. HYGROCELEUTHUS. The genera Hygroceleuthus and Dolichopus are the only ones which have spine-like bristles on the first joint of the hind tarsi, and this character helps to distinguish them most easily from all other Dolichopodidx. They have also the following characters in common : first antennal joint beset with hairs above; third joint not prolonged; arista dorsal; hypopygium entirely disengaged ; its outer appendages proportionally large or moderately large, lamelliform. The difference between the two genera is to be found in the length of the face, which, in Hygroceleuthus, reaches down to the inferior corner of the eye, and which is shorter in Dolichopus. In the typical species of Hygroceleuthus the first, and sometimes also the second joints of the antenne are consider- ably longer than in Dolichopus. As on one side the European Hygroc. Diadema Hal. approaches Dolichopus by the structure of its antenne, so, on the other side, some species of Dolichopus, for instance, D. plumipes Scop., a species common to Europe and North America, are related to Hygroceleuthus by the somewhat greater length of their face. I know as yet only four species of Hygroceleuthus ; of the three typical species, one inhabits northern and middle Europe; the second Siberia; the third North America. The fourth species of the genus is spread over all Europe. The name Hygroceleuthus (éyeoxéaevSos, living in the wet) has been given to the genus on account of the species being found in moist localities. IL. HW. latipes Lorw. % and 9.—Aeneo-viridis, antennis rufis, ciliis oculorum inferioribus pallidis, tegularum ciliis nigris, tarsis intermediis maris compressis. } Brassy green; antenne red; cilia of the inferior orbit pale; cilia of the tegule black; middle tarsi of the male compressed. Long. corp. 0.26. Long. al. 0.23. Syx. Hygroceleuthus latipes Loew, Neue Beitr. VIII, 5. 2 18 DIPTERA OF NORTH AMERICA. [PART II. Green, shining. Antenne reddish-yellow, with a black supe- rior edge and with the tip of the third joint black; first joint nar- row and elongated. Face white, yellowish above, much broader in the than in the ¢. Cilia of the inferior orbit pale. Fore coxe, tip of the middle and hind coxe and feet yellow; tarsi black ~ from the tip of the first joint; the first joint of the fore tarsi some- times altogether dusky ;. the root of the second joint of the hind tarsi, on the contrary, » pale. On the upper side of the middle tibiee a bristle is conspicuous by its greater length; there are two bristles before the tip of the hind tibie. Tegule with black cilia. Wings tinged with brownish; fourth longitudinal vein not broken; hind transverse vein straight and steep. Four last joints of the middle tarsi compressed in the ¢, beset on the upper side with incumbent black hairs; the fifth joint much narrower than the pre- -ceding ones. Costa with a stout swelling near the tip of the first longitudinal vein. Lamellee of the hypopygium of moderate size, white, bordered with black at the tip, jagged and fringed with black bristles. Hab. North Red River. (Kennicott.) Gen. Il. DOLICHOPUWS. The principal characters of the genus Dolichopus, as it follows already from what has been said about it in the genus Hygro- celeuthus, are: the presence of hairs on the upper side of the first antennal joint, the shape of the third joint, which is hardly ever very much elongated, the dorsal position of the arista, the en- tirely disengaged hypopygium, the lamelliform shape of its rather large outer appendages and the presence of spine-like bristles on the first joint of the hind tarsi. The genus Dolichopus, established by Latr ame already in 1796, is the oldest of the family. It comprised at that time all the Dolichopodide, so that all the other genera have been gradually formed by the separation of some groups and by further subdivision of the latter. In the sense in which this genus was adopted by Wiedemann and Meigen, i¢ still included the present genera Gym- nopternus, Paraclius, Pelastoneurus and Tachytrechus, besides some isolated species belonging to other genera, which had been erroneously located in it. (Such was the case, for instance, with D. adustus Wied., which belongs to Lyroneurus.) The defini- DOLICHOPUS. 19 tion of Dolichopus, in its present limited’ sense, was given by me in 1857. Still, even now, this is one of the largest genera of this family. Although possessing abundant and striking specific dif- ferences, its numerous species show at the same time so much agreement in their general organization, that a subdivision into smaller genera is impossible at present, and in future an attempt of that kind will require a great deal of caution. One is easily tempted here to establish generic groups founded upon characters of a purely specific value. The genus Rhagoneura, formed by Rondani, is due to a mistake of this kind. To found a new genus on D. ziczac, which species apparently requires it on account of some differences in the neuration and in the structure of the an- tenn, seems hardly worth while, as this is as yet the only species showing such differences. The geographical distribution of the genus Dolichopus cannot be inferred from the data found in older authors, as this genus con- tained at that time very heterogeneous elements. Neither can Mr. Walker’s superficial publications on exotic species be considered in this respect as a source of information, as it is impossible to tell from his descriptions which of his species belong to Dolichopus in the restricted sense. Those species from the southern hemis- phere, and from the southern parts of the northern, which I had occasion to examine at different times, proved not to belong to Dolichopus in that sense. Hence we may safely conclude that the genus Dolichopus, in the large majority of its species, belongs to the cold and temperate zones of the northern hemisphere; it can, at least, be positively asserted that the number of species, in Europe as well as in America, goes on diminishing toward the South. The name of the genus (Soarx0s, long, and zovs, foot) has refe- rence to the length of the feet of its species. Thirty-one North American species of Dolichopus have been described by former authors; some of them, however, do not belong to this genus in the restricted sense adopted here, Of these species three have been described by Say, one by Zetterstedt, one by Macquart, and twenty-six by Walkér. The descriptions given — by Mr. Walker are, for the most part, very bad, and the worst are those published in the Diptera Saundersiana, as they con- *tain only such characters as are common to all the species, or at least to entire groups, without paying the least attention to those 20 DIPTERA OF NORTH AMERICA. _ [PABr I. marks which serve to distinguish one species from another. The eighteen descriptions contained in the List of Diptera of the British Museum mention at least occasionally such specific cha- racters, and may therefore contain some data for identification ; but their great defect is that Mr. Walker has not given a complete description of those peculiar marks which distinguish the males of many species, so that, from his silence about these marks, one can- not with safety conclude that they are really wanting. This accu- racy is absolutely necessary in order to make a description ayail- able. Among the forty-one North American Dolichopodidzx now known to me, I recognize with certainty only a single species already described before (besides the three species which North Ameyica has in common with Europe, D. plumipes Scop., D. brevipennis Meig., and D. discifer Stann.); it is the D. cuprinus Wied. (= cupreus Say). This striking result induces me to give a separate account of all the other species published. by former authors, in the order of their publication. 1. obscurus Say. This species, also described by Wiedemann, evi- dently belongs to the genus Gymnopternus and will be discussed there. Wiedemann’s collection affords no light upon this species. It contains, it is true, two specimens of a Dolichopus marked obscurus, but this is no other than a species of. Tachytrechus, from the Cape, described by Wiedemann himself under the name of obscenus. It is probable that Wiedemann named this species, as he was in the habit of doing, as soon as he received it in his collection, and that when he described it afterwards, he changed its name to obscenus, on account of the already existing obscurus Say, neglecting, at the same time, to change the etiquette in his collection. 2. abdominalis Say. The abdomen is said to be reddish. If Say means a reddish, non-metallic color, then it is a distinct species, entirely unknown to me, which will be easily recognizable even if it is no true Dolichopus, as may very probably be the case. If, how- ever, he means a metallic, coppery-red coloring, then the descrip- tion is too unmeaning to pronounce even about its belonging to Dolichopus in the restricted sense; as to the identification of the species, it is altogether out of question. 3. groenlandicus Zett. A true Dolichopus with black as the prevailing color of its feet. It is not among the number of the species known to me. 4, heteroneurus Jacq. is either a Pelastoneurus or a Paraclius. 5. bifrons Walk. Dipt. Saund. It may be inferred, from the peculiar | coloring of the face of this species, that it is a Pelastoneurus, DOLICHOPUS. 21 although no mention is made of the peculiar course of the fourth longitudinal vein, which characterizes this genus. 6-9. consors, contingens, hebes, ineptus, all four described by Walker in the Dipt. Saund. from female specimens. The descrip- tions are so wretched that the identification is impossible. 10. maculipes Walk. Dipt. Saund. The spots on the tibie, mentioned by Walker, seem to indicate that this is a Pelastoneurus. But the peculiar course of the fourth longitudinal vein, the chief character of the genus, is again not mentioned. 11. pulcher Walk. Dipt. Saund. I take this to be a true Dolichopus, although the datum of the fourth longitudinal vein beyond its flexure not converging, but being parallel to the third, seems to in- dicate a Gymnopternus. It belongs to the species with black femora, but among the species of this description which I possess from North America, there is none to which Mr. Walker’s description of the fourth longitudinal vein is applicable. 12. varius Walk. Dipt. Saund. A very distinct species on account of its spotted wings and which will he easily recognizable even if, as it seems probable, it does not belong to the genus Dolichopus. 13. affinis Walk. This and the following species have been described by Mr. Walker in the List of Diptera, ete. All belong very probably to the genus Dolichopus, and to the subdivision with yellow feet, except the cases which I have expressly mentioned below. It is not said whether the tegule of D. affinis are ciliated with black or pale hairs. If the latter is the case, and if, as it appears from Mr. Walker’s data, the hind tarsi are altogether black, my D. splendidus might alone be taken in consideration ; but it is hardly possible that it should be this species, as Mr. Walker’s description of the color- ing does not apply to it, and as the hind femora of the 4 of D. affinis Walk. are ciliated with only a few hairs, whereas in D. splendidus these hairs are very numerous. If D. affinis has black cilia on the tegule, then D. discifer and lobatus could be thought of, but the hind femora of their males are entirely destitute of bristles, so that the description of D. affinis cannot be applied to either of them. 14. “njeaet hoe hes Walk. It has the inferior orbit ciliated with black. Among the North American species of Dolichopus with pale-colored feet D. pachycnemus and D. brevipennis alone partake of this cha- racter. The other data of Mr. Walker do not apply at all to these species, as neither of them has a white face, the first antennal joint red and the third joint very long. 15. ciliatus Walk. Very poorly characterized. I suppose that the cilia © of the inferior orbit are pale. If the tegule are likewise ciliated with pale hairs, then D. variabilis and D. luteipennis might be taken in consideration. But D. variabilis has no golden-yellow face, its fore tarsi are not “dark tawny,” but always black from the tip of 22 DIPTERA OF NORTH AMERICA. [PART II. the first joint; besides, its male has ciliated hind femora, which Mr. Walker does not ascribe to his species. D. lutetpennis has a white face and the last joint of its fore tarsi black; its wings are yellowish and not gray, the veins are luteous and not black; finally the hind femora of its male are also ciliated. If the tegule of D. ciliatus are ciliated with black, then we might perhaps identify it with D. vittatus; but the size of the latter is too large to admit of this identification, and its face, instead of being golden-yellow, is whitish; its fore tarsi are not dark tawny but always black from the tip of the third joint. 16. adjacens Walk. Very poorly described from a female specimen, so that it would be entirely useless to attempt its identification. 17. coercens Walk. Mr. Walker says that the coxe are blackish-green towards the basis. This character, combined with the others which are given, excludes at once all the species with the tegule fringed with black, which are known tome. If the tegule are fringed with yellow, this species might be taken for D. longimanus; but the last joint of the fore tarsi of the latter is only moderately enlarged, assuming the shape of a very small lamella, and its hind tarsi are colored black in a rather striking manner from the very root of the first joint; whereas Mr. Walker says that in his species they are pitch brown towards the end. Under such circumstances the des- cription of D, coercens Walk. cannot possibly be referred to D. longimanus. 18. finitus Walk. If the tegule are fringed with pale, then, among the species known to me, D. longimanus, D. splendidus and D. batallifer have to be taken in consideration. The face of D. longimanus is not whitish, but pale ochre-yellowish in the 4% and yellowish gray in the 9: the cilia of the inferior orbit are not white, but yellowish, and the hind tarsi are not pale at the basis, as in D. finitus, but en- tirely black. D. splendidus is distinguished from D. jinitus by its hind tarsi, which are not pale at the base, and by the ciliated hind femora of the male. The face of D. batillifer is not white; the hind femora of the male are ciliated and the hind tibiz incrassated in a very striking manner; therefore this species is also distinct from D. finitus. If the cilia of the tegule of D. finitus are black, then we might compare D. discifer and lobatus with it. The hind tarsi of D. discifer are not pale at the base, and the first joint of the an- tenne is tinged with black only on its upper edge, so that it is hardly probable that Mr. Walker should have overlooked its striking red coloring. This also excludes this species from the identification with D. finitus. The hind tarsi of D. lobatus likewise are not pale at the base, and the first joint of the antenne is red, and only somewhat dusky on its upper edge, so that it has also to be considered as different from D. finitus. DOLICHOPUS. 293 r 19. distractus Walk. Walker says nothing about the sex of the de- scribed specimen; it seems to have been a female. The descrip- tion does not afford any data for even an approximative identifica- tion. 20. discessus Walk. Mr. Walker gives a very unsatisfactory descrip- tion of afemale. It is a rather surprising datum that the apper side of the thorax has two longitudinal coppery-red stripes, whereas all the species known to me, and marked with stripes of this color, have always three,that is, a narrow intermediate one, and two broad lateral ones. This character might perhaps serve as a clue for identification. 21. contiguus Walk. Nothing is said about the color of the cilia of the inferior orbit. If they are black, then it is certain that D. contiguus is not among the species from North America known to me. If they are pale, it still remains to be known of what color are the cilia of the tegule about which Mr. Walker is also silent. Sup- posing that they are pale, then D. splendidus would have to be taken in consideration; but its male has fringed hind femora and cannot therefore be identified with D. contiguus. If the cilia of the tegule are black then we would have to compare “ph discifer and lobatus. But the last joint of the fore tarsi of D. discifer is not at all much enlarged, and forms only a small pallet; therefore it can- not be taken for D. contiguus. D. lobatus has a very much enlarged last joint of the male fore tarsi, but as the first joint of the antenne is red and only slightly dusky on the upper edge, and as the lamelle of the hypopygium have a broad black margin, whereas Walker describes the lamelle of D. contiguus simply-as whitish, as the wings of D. lobatus, in the male sex, are distinguished by their peculiar shape, which is not mentioned in the description of D. con- tiguus, on account of all this we cannot consider these species as being identical. 22. exclusus Walk. Very poorly described from a female, so that all effort to identify the species must remain fruitless. 23. confinis Walk. The same may be said of this species. 24. conterminus Walk. Mr. Walker does not mention the color of the cilia on the tegule, and this renders the identification impossible. If they are black, then the species is not among those known to me. D. discifer and D. lobatus are here again the species with which Mr. Walker’s description agrees in most particulars, but both are easily distinguished by the absence of fringe on the hind femora of the male. If, on the contrary, the cilia of the tegule of D. conterminus are pale, then D. splendidus might possibly be identified with it, although it must be admitted that the coloring of this species as well as some other characters, somewhat disagree with Mr. Walker’s description. 24 DIPTERA OF NORTH AMERICA. “ [ PART II. 25. separatus Walk. Bad description of a female, rendering identifica- tion impossible. 26. terminatus Walk. Also a female described. The only species to which it may possibly be referred is D. chrysostomus, and I would have no doubt about it if I knew that the cilia of the tegule of D. terminatus are black. But Mr. Walker’s description is silent about this; neither does it mention the very striking black incisures which the abdomen of D. chrysostomus shows; finally, the third joint of the antenne of the latter species is pointed at the tip. Con- sidering all this, it would be premature to assume the identity of these species. Those who,.in the determination of the species, rely upon possibilities and vague reasonings, would perhaps do so. And doubtless it is that the adoption of this synonymy would be more reliable than that of any other of Walker’s species with one of those described by me. 27. sequax Walk. Mr. Walker says that this species has small tufts of black hairs at the basis of the middle tibie. He does not mention, however, whether this peculiarity is to be found in the male alone, or in both sexes. At all events this is a very unusual distinction among the species of Dolichopidz, which will render the identifica- tion easy. This species is not among those described by me. 28. soccatus Walk. The sex of the described specimen is not men- tioned ; it seems to have been a female. The description is too in- complete to allow recognition. 29. remotus Walk. Description of a male with plain tarsi. The cha- racters given allow a comparison merely with D. incisuralis, the male of which, however, has fringed hind femora and cannot there- fore be identical with D. remotus. 30. D. irrasus Walk. This is a small species, distinguished by its dark blue color and unusually short abdomen, which is certainly not to be found among the species known to me. It seems probable that it is no true Dolichopus at all. The slender result of the foregoing discussion of Mr. Walker’s species is, that there are only two among them which, with cer- tain problematical admissions, may perhaps be identified with species described by me, namely, D. conterminus Walk. with my D. splendidus, and D. terminatus with D. chrysostomus. To facilitate the determination of the species I give, first, a dichotomic table. J found it impossible to bring it down to the single species without making use of characters peculiar to the DOLICHOPUS. 25 male sex only. The systematic arrangement which follows the dichotomic table subdivides the genus in groups, founded upon easily perceptible characters common to both sexes. I think it will be useful to retain these groups, or, at least, the principal among them. Table for determining the Species. 1 { Prevailing color of the feet black. D) Prevailing color of the feet yellowish. 9 2 | Cilia of the inferior orbit black. 3 Cilia of the inferior orbit whitish. 4 3 | Face ochre yellowish. 1 gratus Lw. Face silvery white. 2 laticornis Zw. 4 | First joint of hind tarsi with numerous bristles. 3 setifer Lw. First joint of hind tarsi with but few bristles. 5 5 { Hind tibie black only at the tip. 6 Hind tibie quite black. ; ik (The black at the tip of the hind tibiw rather extended and not very 6 j sharply limited. 4 albiciliatus Zw. | The black at the tip of the hind tibie but little extended and sharply L limited. 5 xanthocnemus, N. sp. 0 | A considerable extent of the tip of the femora yellow. 6 tetricus, n. sp. The extreme tip of the femora only somewhat yellow. 8 8 { Lamelle of the hypopygium pointed. 7 acuminatus Zw. Lamelle of the hypopygium rounded ovate. 8 ovatus Lw. 9 { Cilia of the inferior orbit black. 10 Cilia of the inferior orbit pale. 11 10 { Fore coxe blackish. 9 pachycnemus Lw. Fore coxe yellow. 10 brevipennis JMeig. ll | Tegule with pale cilia. 12 Tegule with black cilia. cae f Antenne black, at the utmost, the first joint almost red. 13 U Antenne altogether, or at least their larger portion, yellowish red. 21 13 { Fore coxe dark beyond the middle. 11 longimanus Lw. Fore coxe pale. 14 Tip of the hind tibize decidedly blackish. 15 Tip of the hind tibiz not or very slightly infuscated. 16 Fore tarsi only ferruginous-brownish. 12 brevimanus Lw. Fore tarsi blackened from the tip of the first joint. 13 socius Lw. { Hind tarsi entirely black. sa Basis of the hind tarsi pale to a considerable extent. uy Hind femora of the male not ciliated. 14 nudus, n. sp. Hind femora of the male ciliated. 18 26 DIPTERA OF NORTH AMERICA. [PART II. ( Hind femora of the male with sparse and rather short cilia. 15 subciliatus, n. sp. 18 4 Hind femora of the male with very long and dense cilia. 16 splendidus Lw. Only the last joint of the fore tarsi of the male is enlarged. 19] 17 batillifer Lw. The two last joints of the fore tarsi of the male are enlarged. 20 { Hind femora of the male ciliated. 18 eudactylus Lw. Hind femora of the male not ciliated. 19 tonsus Lw. 2] { Last joint of the fore tarsi of the male enlarged. 20 tener Lw. Fore tarsi of the male plain. 22 99 { Wings hyaline with a grayish tinge. 21 variabilis Zw. Wings hyaline with a yellowish tinge. 22 luteipennis Lw. Fourth longitudinal vein broken. 24 Fourth longitudinal vein not broken. 28 Antenne black. . 23 ramifer Lw. Antenne yellowish-red. 25 Fourth longitudinal vein broken twice at right angles. 24 bifractus Zw. 25 The inferior angle of the fourth longitudinal vein sharp, the superior one rounded. 26 Tarsi of the male plain. _ 25 vittatus Zw. Tarsi of the male enlarged at the tip. 27 gr J Hind femora of the male ciliated. 26 cuprinus Weed. 7) Hina femora of the male not ciliated. 27 longipennis Lw. Antenne red, at the utmost the third joint somewhat or altogether 25| blackened at the tip. 29 Antenne black, at the utmost the first joint partly red. 36 Humeral callosity of the same color with the upper side of the thorax. 29 30 Humeral callosity yellowish. 8 35 Arista much enlarged towards the tip in the male. 28 hastatus, n. sp. Arista of the male not enlarged. ol 31 eee joint of the fore tarsi not enlarged in the male. 32 Last joint of the fore tarsi enlarged in the male. ae 39 { First joint of the male middle tarsi feathered. 29 plumipes Scop. First joint of the male middle tarsi not featheréd. 30 fulvipes Zw. Last joint of the male fore tarsi with a lamelliform appendage. =| 31 sexarticulatus, n. sp. Last joint of the male fore tarsi without lamelliform appendage. 34 2a joint of the male fore tarsi small. 32 ruficornis Lw. Last joint of the male fore tarsi large. (40 lobatus Lw.) 35 { Fore tarsi of the male plain. 33 scapularis Lw. Fore tarsi of the male enlarged at the tip. 34 funditor Lw. 36{¥ ace dark golden-yellow. 35 chrysostomus Lw. Face not golden-yellow. 37 ‘ DOLICHOPUS. a Tip of the hind femora infuscated above. 38 ise of the hind femora not infuscated above. 39 38 j Fore femora on the under side with a black stripe. 36 preeustus Lw. Fore femora without black streak. 37 comatus Lw. Fore tarsi black only at the tip. 40 Fore tarsi black from the tip of the first joint. 41 Two last joints of the male fore tarsi but little enlarged, feathered 40 with black. 38 scoparius, I. sp. Two last joints of the male fore tarsi enlarged, not feathered. 39 discifer Stann. 4l { Last joint of the male fore tarsi very much enlarged. 40 lobatus Lw. Fore tarsi of the male plain. 42 Bristles of the hind tibiz longer than usual. 41 setosus Lw. Bristles of the hind tibie not longer than usual. 42 incisuralis Lw. Systematic distribution of the Species. I. Prevailing color of the feet black. A. Cilia of the inferior orbit black. 1. gratus Lw. 2. laticornis Lw. B. Cilia of the inferior orbit whitish. 3. setifer Lw. 6. tetricus, n. sp. 4. albiciliatus Lw. 7. acuminatus Lw. 5. xanthocnemus, n.sp. 8. ovatus Lw. x II. Prevailing color of the feet yellowish. A. Cilia of the inferior orbit black. 9. pachycnemus Lw. 10. brevipennis Mezg. B. Cilia of the inferior orbit pale. A. Cilia of the tegule pale. 1. Antenne black, the first joint at the utmost partly red. 11. longimanus Lw. 16. splendidus Lw. 12. brevimanus Lw. 17. batillifer Zw. 13. socius Lw. 18. eudactylus Lw. 14. nudus, n. sp. 19. tonsus Lw. 15. subciliatus, n. sp. 2. Antenne entirely, or their greater portion, yellowish red. 20. tener Lw. 22. luteipennis Lw. 21. variabilis Zw. 28 DIPTERA OF NORTH AMERICA. [ PART II. B. Cilia of the tegule black. 1. Fourth longitudinal vein broken. a. Antenne black. 23. ramifer Lw. b. Antenne yellowish-red. 24. bifractus Lw. 26. cuprinus Lw. 25. vittatus Lw. - 27. longipennis Lw. 2. Fourth longitudinal vein not broken. a. Antenne red, at the utmost the third joint at the tip almost entirely red. a. Humeral callosity of the same color with the thorax. 28. hastatus, n. sp. 31. sexarticulatus, n. sp. 29. plumipes Scop. 32. ruficornis Lw. 30. fulvipes Lw. &. Humeral callosity yellowish. 33. scapularis Lw. 34. funditor Lw. b. Antenne black, at the utmost thesfirst joint partly red. 35. chrysostomus Jw. 39. discifer Stann. 36. preeustus Lw. 40. lobatus Lw. 37. comatus Lw. ~ 41. setosus Lw. 38. scoparius Lw. 42. incisuralis Lw. DOLICHOPUS. 29 DESCRIPTION OF THE SPECIES. I. PREVAILING COLOR OF THE FEET BLACK. A. Cilia of the inferior orbit black. 1. D. gratus Lorw. 4 .—Ex viridi chalybeus, pedum nigrorum tibiis anterioribus totis tibiarumque posticarum dimidio basali flavis, facie ochracea, ciliis oculorum inferioribus tegularumque ciliis nigriis. Bluish-green, feet black, the four anterior tibie entirely, the two hind ones upon the basal half yellow; face ochre-brownish; cilia of the inferior orbit and of the tegule black. Long. corp. 0.23—0.24. Long. al. 0.21. Syn. Dolichopus gratus Lorw, Neue Beitraige, VIII, 11, 1. Bluish-green. The narrow face ochre-brownish. Antenne black; the first joint rather narrow. Front metallic bluish-green. - The cilia of the inferior orbit black. Lamelle of the hypopygium whitish, of moderate size, on the upper and the apical margin with a moderately broad black border; the apical margin somewhat ‘jagged and fringed with numerous black bristles. Femora black, with yellow tip; the hind femora rather stout, provided with a bristle before the tip; upon the under side ciliated with long black hair; the four anterior tibie and tarsi yellowish, the latter ones but little darker towards the tip; hind tibie somewhat thickened, the apical half and the whole of their hind side black, the remain- ing parts yellowish; hind tarsi quite black, the first joint with few bristles. Tegule with strong black cilia. Wings hyaline, the costa is thickened before the tip of the first longitudinal vein, and only very gradually attenuated beyond; the end of the fourth lon- gitudinal vein converges towards the third. Hab. Trenton Falls, West Point, Palisades, ete., N.Y. (Os- ten-Sacken. ) 2. D. laticermis Lorw. %.—Viridis pedum nigrorum tibiis, excepto posticarum apice, flavis, facie alba, ciliis oculorum inferioribus nigris, tegularum ciliis albis. Green, feet black; tibie, excepting the tip of the hind ones, yellow; face 30 DIPTERA OF NORTILT AMERICA, [PART II, white; cilia of the inferior orbit black; cilia of the tegula white. Long. corp. 0.17. Long. al. 0.15. Syn. Lolichopus laticornis Loew, Neue Beitr. VIIT, 12, 2. Face white, rather broad for a male. Antenne black; the third joint large and broad, ovate; arista inserted upon its second third. Front metallic green. The cilia of the inferior orbit black. © Lamelle of the hypopygium rather small, of a trapezoidal form, the upper and apical margin are but very little bordered with black; their margin is not jagged but only fringed with minute black hairs. Tip of the coxe yellow. Femora black, with a faint greenish reflection and yellow tip. Tibix yellowish. (The middle tibix are wanting in the deseribed specimen.) The tip of the hind tibix, which are not thickened at all, is black. Fore tarsi from the tip of the first joint black; hind tarsi entirely black; the first joint is beset with a few thorn-like bristles. Hind femora before the tip with a stout bristle. Tegule with whitish cilia. Wings hyaline; the costa but searcely thickened about the tip of the first longitudinal vein; the end of the fourth longitu- dinal vein converges towards the third. Hab. Connecticut. (Norton. ) B. Citta of the inferior orbit pale. 3. D. setifer Lorw. %.—Obscure viridis, pedum nigrorum tibiis an- terioribus posticarumque dimidio basali flavis, facie alba, ciliis oculorum inferioribus tegularumque ciliis albidis, metatarso postico valde setoso. Dark green; feet black, the four anterior tibim and the basal half of the two hind ones yellow; face white; the cilia of the lower orbit and of the tegule whitish; the first joint of the hind tarsi with many thorn-like bristles. Long. corp. 0.17. Long. al. 0.15. Syn. Dolichopus setifer Loew, Neue Beitr. VIII, 12, 3. Face silvery-white, narrow. Antenne black, third joint short, Front metallic green. The cilia of the inferior orbit whitish. The lamelle of the hypopygium whitish; their long apical margin is finely jagged only below and fringed with long bristles, above only finely hairy; its lower corner has a narrow black border. The black femora show a green reflection and have a clayish-yel- low tip; the hind femora have a bristle before their tip and are ciliated on their under side with long black hairs; the four anterior tibix are clayish-yellow; the first joint-eof the four anterior tarsi DOLICHOPUS. 31 is of the same color; its tip and the remaining joints are black. The hind tibie are black; upon their upper side, from the base beyond the middle, clayish-yellow; towards their tip but little thickened; the first joint of the hind tarsi is covered with many thorn-like bristles. Tegule with whitish cilia. Wings entirely hyaline, towards the base somewhat wedge-shaped, with a black spot which occupies their very tip. The costa is hardly thickened near the tip of the first longitudinal vein; the end of the fourth longitudinal vein converges towards the third. Hab. District Columbia ; Trenton Falls, N. Y. (Osten-Sacken. ) A. D. albiciliatus Lozw. 9.—Obscure viridis, pedum nigrorum tibiis, posticarnm apice tamen excepto, tarsorumque anteriorum basi flavis, facie alba, ciliis oculorum inferioribus albis, tegularum ciliis nigris. Dark green; feet black, tibie, excepting the tip of the hind ones, and the basis of the four anterior tarsi, yellow; face white; cilia of the inferior orbit white; cilia of the tegule black. Long. corp. 0.20. Long. al. 0.20. Syx. Dolichopus albiciliatus Lozw, Berl. Ent. Monatschr. VI, 211, 59. Dark green. Face proportionally rather broad, white. An- tennz black, third joint short. Front metallic green. Cilia on the inferior orbit white. Femora black, with a greenish reflection, their extreme tip brownish-yellow; on the under side of the hind femora the hairs are somewhat longer than in the related species, and of such a kind as to lead to the supposition that the male has the hind femora ciliated with black. Tibiz yellow, the tip of the hind ones black; this black coloring occupies on the anterior side perhaps the fourth, on the hind side nearly the third part. On the four anterior tarsi the four last joints, including the tip of the first joint, are black; the hind tarsi are entirely black; their first joint is as long as the second, upon its upper side with two bris- tles, and upon its under side with one. Cilia of the tegulz black. Wings hyaline. ° Hab. Mlinois. (Le Baron.) + 5. D. xanthocnemus, n. sp. % and 9.—Obscure viridis, pedum nigrornm tibiis, posticarum apice tamen excepto, tarsorumque anteriorum basi flavis, facie alb4, ciliis oculorum inferioribus albis, tegularum ciliis nigris, femoribus maris posticis albo-ciliatis. Dark green; feet black, tibie, excepting the tip of the hind ones, and the 32 DIPTERA OF NORTH AMERICA. [PART II. base of the four anterior tarsi, yellow; face white; cilia of the inferior orbit white; cilia of the tegule black; hind femora of the male ciliated with white. Long. corp. 0.15—0.16. Long. al. 0.17—0.18. In the color and even the structure of the body this species re- sembles D. albiciliatus ; but it is much smaller. Face white, that . of the male rather narrow, that of the female proportionally rather broad. Palpi blackish at the base, at the tip more yellowish and with a somewhat whitish reflection. Antenne black; third joint rather short, in the ¢ somewhat larger than in the ¢. Front metallic green. Cilia of the posterior orbit black above, white on the side and below. Coxe black, trochanters brownish-yellow. The fore coxe dusted on their fore side and beset with black hair. Femora black, with brownish-yellow tip, the hind ones before the tip with a bristle. The hairs of the femora are black, but there are on the under side of the four anterior femora of the male some delicate and short white hairs. The under side of their hind femora is ciliated with very long white hairs; upon the under side of the anterior femora of the female the hairs are closer than in the male, and show a whitish appearance only in a certain direction, whilst in another direction they appear rather blackish. Tibie yellowish; the hind tibiee are colored with black at the tip; this black coloring has but a moderate extent and is rather sharply limited. Tarsi plain in both sexes; on the four anterior ones the tip of the first joint and the four following joints are co- lored black; the hind tarsi are entirely black; in the male their first joint has more thorn-like bristles than in the female. Cilia of the tegule black, but mixed with minute white hairs, as it is also the case with the related species, for instance with D. albici- liatus. Wings grayish hyaline; in the male the anterior margin has at the tip of the first longitudinal vein a small knot-shaped swelling. ‘The white lamellee of the hypopygium are of a rounded- ovate form, bordered with black, jagged on the upper and apical margins and fringed with black bristles. . Hab. Sitka. (Sahlberg.) Observation.—Between the diagnosis of this species and that of D. albiciliatus there is no difference with regard to the female sex except in the size. Indeed the females of both species are very much alike. In order to distinguish them it will be well to bear in mind that the female of D. xanthocnemus is not only DOLICIOPUS. 0" . much smaller, but that the incisures of its abdomen are less blackened, that the black coloring on the tip of its hind tibie is Jess extended and more sharply limited, and that finally the short hairs upon the under side of its fore and middle femora have, in a reflected light, for the most part a whitish appearance, whilst in the female of D. albiciliatus this is the case only in the proximity of the base of the fore femora. 6. D. tetricus,n.sp. % and 9.—Obscure viridis, rarius cupreus, antennis pedibusque nigris, apicali femorum triente testaceo, inferioribus oculorum ciliis flavicantibus, alis cinereis. 4%. Facie exochraceo-cine- rea, lamellis hypopygii albidis, ultimo tarsorum anticorum articulo dilatato, tibiis posticis crassiusculis. Q. Facie albida, pedibus simpli- cibus. Dark green, seldom coppery; antenne and feet black, the last third of the femora brownish-yellow; cilia of the inferior orbit yellowish; wings grayish. 4%. Face yellowish-gray; lamelle of the hypopygium whitish ; the last joint of the fore tarsi enlarged: hind tibie somewhat thickened. QO. Face white; feet plain. Long. corp. 0.18—0.20. Long. al. 0.20— 0.22. . Dark green, bright; the last segments of the abdomen are usually dark bronze-colored, and sometimes the color of the body is everywhere very coppery. Antenne black; the third joint almost round, still with a sharp projection at the tip. Front me- tallic green. The face of the male not very narrow, yellowish gray ; the face of the female much broader, whitish. Palpi black, dusted with whitish on the edge, particularly in the female. , Cilia of the inferior orbit yellowish, sometimes nearly whitish. Hypopygium with elliptic, whitish lamelle of moderate size, which are bordered with black on the upper and apical margin; the latter is somewhat jagged. Coxe black; fore coxe with black hairs and bristles, only very slightly dusted with white. Feet black; the last third of the fore and middle femora, as also somewhat more than the last quar- ter of the hind femora, reddish luteous-yellow or almost yellowish- red; the hind femora before the tip with a seta, not ciliated upon their under side, evenin the ¢. The tibise show only at the very extreme base a lighter color; in the Q all tibie are of a plain structure, in the ¢ the hind tibie are conspicuously thickened. - The ? has plain tarsi, in the male the last joint of the fore tarsi is flattened from the side, and enlarged above into a lobe; the first joint of the hind tarsi in both sexes is but little fringed with 9 Oo 9 34 DIPTERA OF NORTH AMERICA. [PART TE. thorn-like bristles. Cilia of the tegule black. Wings grayish ' with brownish-black veins; the last section of the fourth longi- tudinal vein has a rather strong flexure in the middle, but from that point runs nearly parallel with the third longitudinal vein ; the ¢ has no swelling of the costa at the tip of the first longi- tudinal vein. Hab. Fort Resolution, Huds. Bay Territory. (Kennicott.) %. D.acumimatus Lorw. % and 9.—Obscure viridis, pedum ni- grorum tibiis anticis ex flavo fuscis, facie alba, ciliis oculorum inferiori- bus albis, tegularum ciliis nigris, lamellis hypopygii magnis, acutis. Dark green; the feet black, fore tibiw brownish-yellow ; face white; cilia of the inferior orbit white, of the tegule black; the large lamelle of the hypopygium pointed at the end. Long. corp. 0.15. Long. al. 0.14— 0.15. Syn. Dolichopus acuminatus Lozrw, Neue Beitr. VIII, 12, 4. Male. Dark green. Face narrow, white. Antenne black; their third joint short. Front metallic green. Lamelle of the hypopygium white, large, spatule-shaped, pointed, so that the upper and the lower margin strike together and there is no dis- tinct apical margin; the upper one has a narrow black border and is ciliated with minute black hairs. The black femora with a bluish-green reflection, and their extreme tip brownish-yellow ; fore tibizee upon the greatest part of the upper side brownish-yel- low, dark brown beneath; fore tarsi brownish-black with yellow base; middle tibiz and middle tarsi brownish-black, still the base of the latter yellowish-brown; hind tibiz and hind tarsi entirely black, the latter sparsely bristly upon the first joint. Cilia of the tecule black. Wings hyaline; the costa at the tip of the first longitudinal vein not thickened; the end of the fourth vein con- verging towards the third; the hind transverse vein somewhat less steep than in D. ovatus. Female. Very much like the male. The white face much broader than in the male, still not so broad as in the female of D. albiciliatus. The yellow coloring upon the upper side of the fore tibie is not only generally lighter than in the ¢, but also often distinctly observable upon the first half of the upper side of the middle tibia. Hab. Washington. (Osten-Sacken.) Illinois. (Le Baron.) DOLICHOPUS. aii, _ 8. D. ovatus Lozrw. %.—Obscure viridis, pedum nigrorum tibiis an- ticis ex flavo fuscis, facie alba, ciliis oculorum inferioribus albidis, tegu- larum ciliis nigris, lamellis hypopygii parvis, rotundato-ovatis. Dark green; feet black, fore tibiz brownish-yellow; face white; cilia of the inferior orbit whitish, of the tegule black; lamellz of the hypopygium small, rounded-ovate. Long. corp. 0.15. Long. al. 0.14—0.15. Syy. Dolichopus ovatus Loew, Neue Beitr. VIII, 13, 5. Face narrow, white. Antenne black, third joint short. Front metallic green. Cilia of the inferior orbit whitish. Lamelle of the hypopygium white, rather small, roundish-ovate, on the upper and apical margin with a narrow black border, on the latter split into a bristle-like lobe and fringed with black bristles. Feet black ; the femora with a somewhat greenish reflection; their ex- treme tip brownish-yellow; the root of the fore and middle tarsi : are of the same color. Fore tibiz upon the greatest part of the upper side brownish-yellow, beneath dark brown. Middle tibiz and middle tarsi brownish-black. Hind tibiae and hind tarsi black. Cilia of the tegule black. Wings hyaline; the costa at the tip of the first longitudinal vein not thickened. The end of the fourth longitudinal vein converges towards the third; the hind transverse vein straight and steep. Hab. Middle States. (Osten-Sacken. ) Observation.—The 2 of D. ovatus, which is not known to me, must resemble very much that of D. acuminatus. Besides the but slight discrepancy in the color of the feet, the difference con- sists probably in the coarser hairs on the fore coxe; at least the hairs in the ¢ of D. ovatus are coarser and also longer than in that of D. acuminatus. The difference in the direction of the hind transverse vein, in the males of both species, is not sufficient to be relied upon for an easy discrimination of the 2 of the same species. II. PREVAILING COLOR OF THE FEET YELLOWISH. A. Cilia of the inferior orbit black. 9. D. pachycnemus Lorw. % and ?-—Aeneo-viridis, antennis, oculorum tegularumgue ciliis nigris, coxis omnibus totis obscuris, pedi- bus flavis, dimidio tibiarum posticarum apicali, tarsis intermediis inde ab articuli primi apice, posticisque totis nigris. %. Tarsis anticis attenuatis, articulis tribus ultimis atris, compressis, 36 DIPTERA OF NORTH AMERICA. [PART IL. duobus ultimis valde dilatatis, femoribus posticis nigro-ciliatis, tibiis posticis incrassatis. ©. Pedibus simplicibus, tarsis anticis inde ab articuli primi apice nigris. Metallic green; antenne, cilia of the inferior orbit and of the tegule black ; all coxe entirely dark; tarsi yellow; the whole second half of the hind tibie, the middle tarsi from the tip of the first joint and the whole hind tarsi black. *. Fore tarsi attenuated ; the three last joints black, compressed, the two last joints much enlarged; hind femora ciliated with black; hind tibiz incrassated. : ©. Feet plain, fore tarsi from the tip of the first joint blackened. Long. corp. 0.25—0.26. Long. al. 0.22. Syn. Dolichopus pachycnemus Lonw, Neue Beitr. VIII, 13, 6. . Dark metallic green, bright. Face of the ¢ narrow, ochre-yel- low; face of the 2 broad, grayish-yellow. Antenne entirely black; the third joint ovate. Front bright, generally for the most part steel-blue. The cilia of the inferior orbit black. Thorax with a rather broad brass-colored middle line. Abdomen coppery towards the end. All the coxe black, only their extreme tip somewhat brownish-yellow.- Feet dark yellow; hind femora on the extreme tip darker, before the same with a strong bristle; all tibise with numerous bristles; hind tibiz upon the entire second half black; middle tarsi from the tip of the first joint black; hind tarsi entirely black. 'Tegulee with black cilia. Wings some- what shorter than usual, in the 2 somewhat more dusky than in the male, especially somewhat darker towards the fore margin. Male. Fore tarsi not very much longer than the fore tibiz; their first and second joints slender, stalk-like, yellow; the first one much longer than the second; the following joints black, flat- tened; the third somewhat broader towards the end; the fourth much enlarged, of a nearly triangular form, beset upon the upper side with short, close, minute black hairs; the fourth joint is like- wise much enlarged, still not as broad as the third, and of a more ovate form. Hind tibiee much thickened, stoutest in the middle, and marked upon the upper side with a narrow pale line running from the middle to the tip; hind femora ciliated beneath with long black hairs. Lamelle of the hypopygium dingy yellow, with a broad black border, of moderate size and of a rather round shape, jagged on the apical margin and fringed with black bristles. Female. Feet plain; the fore tarsi rather blackish already from DOLICGHOPUS. 37 the tip of the first joint, which is sometimes the case in ¢, but only in very dark-colored specimens. Hab. Middle States. (Osten-Sacken.) Illinois. (Kennicott.) 10. D. brevipemmnis Meic. % and 9.—Aen¢o-viridis, antennis, oculorum tegularumque ciliis nigris, coxis anticis praeter basim pedi- busque flavis, triente tibiarum posticarum apicali, tarsis, intermediis inde ab articuli primi apice, posticisque totis nigris. %.- Tarsis anticis attenuatis, articulis duobus ultimis atris, compressis, ultimo eximie dilatato, femoribus posticis pallide-ciliatis. Q- Pedibus simplicibus, tarsis anticis inde ab articuli primi apice nigris. Metallic-green ; antennz, cilia of the inferior orbit and of the tegule black; fore cox, excepting the basis, and feet yellow; the last third of the hind tibiz, the middle tarsi from the tip of the first joint and the whole hind tarsi black. *,. Fore tarsi attenuated, the two last joints black, flattened, the last one extremely enlarged; the hind femora ciliated with pale hairs. ®. Feet plain; the fore tarsi from the tip of the first joint black. Long. corp. 0.24—0.25. Long. al. § 0.22; 9 0.24—0.25. Syy. Dolichopus plumitarsis (var. 8.) Fauuzn, Dol. 10, 4. Dolichopus brevipennis MEIcEN, Syst. Beschr. IV, 89, 27.—Srawnvs, Isis, 1831, 60, 12.—Zerrerstepr, Ins. Lapp. 700, 8.—Sraxrcer, Kroyer Tidsskr. IV, 23, 13.—Zerrerstept, Dipt. Scand. II, 603.—Wa.kKeErR, Dipt. Brit. I, 160, 10. : Dark metallic green, bright. Front green. Antenne black. Face of the ¢ grayish-yellow; that of the 2 grayish-white, slightly yellowish, much broader than in the ¢. Palpi brown. Cilia of the inferior orbit black. Hypopygium black. Lamelle large, oblong-ovate, dingy-yellowish, with a broad black border, on the apical margin somewhat jagged and fringed with crooked black bristles. The hind coxe blackish, only on the extreme tip yellow. Fore. coxe yellow, hairy with black; on the outside of the basis with a somewhat triangular greenish-black spot. Feet yellow. Hind femora before the end only with one bristle; in the & they are sparsely ciliated beneath with very long, yellowish hairs. On the hind tibie the last third at least is black; hind tibie of the perceptibly stronger than those of the 9°, but not near so strong as those of the male of D. pachycnemus; they have no large bare spot upon their hind side, but at the end of the upper side a straight, pale, longitudinal line occupying the whole of their last third. The fore tarsi of the ¢ are about 14 38 DIPTERA OF NORTH AMERICA. [PART II. the length of the tibie; their three first joints are style-like, very attenuated, generally brownish-yellow; their two last joints are black, flattened from the side, the penultimate but little, the last joint on the contrary very much enlarged. ‘The fore tarsi of the @ are plain, blackish from the tip of the first joint. Middle tarsi of both sexes plain, black from the tip of the first jot; upon the second half of the upper side of their first joint a single stronger bristle is inserted. Hind tarsi always altogether black. Cilia of the tegule black. Wings of the ¢ somewhat less grayish than those of the °, proportionally somewhat shorter and more pointed, with a strong swelling of the costa near the tip of the first longi- tudinal vein. The hind transverse vein almost perpendicular ; the last portion of the fourth longitudinal vein not broken. Hab. Fort Resolution, Hudson’s Bay Territory. (Kennicott.) Observation.—The identity of Mr. Kennicott’s specimens with the European D. brevipennis may be considered as doubtless, after the most careful comparison. B. Cilia of the inferior orbit pale. A. Cilia of the tegulz pale. 1. Antenne black, at the utmost the larger portion of the first joint red. ii. D. lomgimanus Lorw. % and 9.—Aeneo-viridis, facie maris pallide ochracea, feeminze ex flavo cinerascente, antennis nigris, ciliis oculorum inferioribus tegularumque ciliis flavicantibus, coxarum anti- carum dimidio basali obscuro, pedibus flavis, tarsis posticis totis nigris ; maris ultimo tarsorum anticorum articulo valde dilatato femoribusque - posticis ciliatis. i Metallic green; the face of the % pale ochre-yellowish, that of the 9 yel- lowish-gray ; antenne black ; cilia of the inferior orbit and of the tegulez yellowish ; basal half of the fore coxe dark; feet yellow with entirely black hind tarsi, last joints of the % fore tarsi enlarged and 4 hind femora ciliated. Long. corp. 0.26—0.27. Long. al. 0.27—0.28. Syn. Dolichopus longimanus Lorw, Neue Beitr. VIII, 14, 7. Bronze-green, rather bright. Face of the ¢ narrow, pale ochre-yellow; face of the 2 rather broad, light yellow-grayish. Antenne entirely black, lower corner of the third joint with a scarcely perceptible lighter coloring; third joimt of the antennz in the ¢ short ovate, in the 2 almost round. Front bright, green or blue-green. The cilia of the inferior orbit yellow. DOLICHOPUS. 39 Upper side of the thorax somewhat pruinose, with a coppery middle stripe and with a somewhat coppery-colored mark on each side before the transverse suture, sometimes coppery on a larger extent. Basal portion of the fore cox blackish beyond the mid- dle; on the middle and hind ones this coloring extends almost as far as the extreme tip. Feet yellow; fore tarsi black at the tip only, middle ones from the tip of the first joint; hind tarsi entirely black; the hind femora before the tip with a bristle. Tegule with yellowish cilia. Wings rather large, hyaline; the fourth longi- tudinal vein not broken. Male. The lamelle of the hypopygium whitish, on the upper margin with a narrow, on the apical one with a broader black border, ovate; their apical margin is fringed with black bristles and jagged on its lower part. Fore tarsi slender and nearly twice as long as the tibie; the four first joints yellow; first joint as long as four-fifths of the tibize; second joint half as long as the first; the third. one but little shorter than the second; the fourth only about half as long as the third; the fifth joint but little longer than the fourth, black, flattened, beset upon the upper margin with appressed black hairs. Hind femora upon the second half of the under side closely ciliated with yellow hairs. Hind tibie somewhat stout, without being actually thickened; they are glabrous upon the anterior half of their hind side. Costa near the tip of the first longitudinal vein with an elongated swelling. flab. English river. (Kennicott.) West Point, N. Y. (Os- ten-Sacken. ) . 12. D. brevimanus Lorw. %4.—Aeneo-viridis, facie alba, antenna- rum nigrarum articulo primo subtus rufo, ciliis oculorum inferioribus albis, tegularum ciliis pallide flavicantibus, pedibus flavis, coxis anticis concoloribus, tarsis anticis ex flavo pallide ferrugineis, intermediis inde ab articuli primi apice posticisque totis cum tibiarum apice nigris. Metallic-green; face white; the first joint of the black antenne upon the under side red; cilia of the inferior orbit white, of the tegule yellowish; the fore coxe and feet yellow; the fore tarsi pale rusty-brownish ; mid- dle ones from the tip of the first joint and the whole hind ones, including the tip of the tibie, black. Long. corp. 0.17. Long. al. 0.17. Syn. Dolichopus brevimanus Lorw, Neue Beitr. VII, 14, 8. Metallic-green, bright. Face white. Antenne black; the whole lower margin of the first joint red; third joint ovate, not 40 DIPTERA OF NORTH AMERICA. [PART II. rounded at the tip. Front bright bluish-green. Cilia of the in- ferior orbit white. Lamelle of the hypopygium white, of medium size and of ovate form, upon the upper and apical margin with a narrow black border, and fringed with black bristles; on the apical margin somewhat jagged. Fore coxe yellowish-white, with- out minute black hairs upon the anterior side; middle and hind coxe blackish with whitish-yellow tip. Feet light yellow; hind femora beset with somewhat longer minute black hairs, without being actually ciliated. Hind tibie plain, upon the hind side without glabrous stripe, at the tip blackish. Fore tarsi only as long as the tibie and but little darker than those, yellow- brownish ; middle tarsi black from the tip of the first joint; hind tarsi. entirely black. Tegula with pale yellowish cilia. Wings hyaline, towards the fore margin with a faint brownish-gray tinge; costa near the tip of the first longitudinal vein although somewhat stouter, not actually thickened; the fourth longitu- dinal vein not broken. Hab. Washington. (Osten-Sacken. ) 13. DB. socius Lorw. %.—Aeneo-viridis, facie alb4é, antennarum ni- grarum articulo primo subtus rufo, ciliis oculorum inferioribus albis, tegularum ciliis dilute flavicantibus, pedibus flavis, coxis anticis con- coloribus, tarsis anterioribus inde ab articuli primi apice, apice tibiarum posticarum tarsisque posticis totis nigris. Metallic-green; face white; the first joint of the black antenne upon the under side red ; cilia of the inferior orbit white ; cilia of the tegule pale yellowish ; fore coxe and feet yellow, the four anterior tarsi from the tip of the first joint, the tip of the hind tibie and the whole hind tarsi black. Long. corp..0.17. Long. al. 0.17. Syn. Dolichopus socius Lozw, Berl. Entom. Zeitschr. VI, 211, 60. Metallic-green, bright. Face white. Antenne black; the whole lower margin of the first joint red, the third joint ovate, not rounded at the tip. Front bright, bluish-green. Cilia of the in- ferior orbit white. Lamelle of the hypopygium white, of medium size, ovate, on the upper and apical margin with a narrow black border and fringed with black bristles, on the apical margin ‘somewhat jagged. Fore coxe yellowish-white, without minute black hairs upon the front side; middle and hind coxe blackish, with yellowish tip. Feet pale yellow; hind femora upon the un- der side with but extremely short hardly visible hairs; hind tib‘e DOLICHOPUS. 4] blackish at the tip; upon the hind side without glabrous stripe; fore tarsi but little longer than the tibie, rather slender, blackened from the tip of the first joint, still so that the extreme basis of the second and sometimes even that of the third joint remain pale; the last joint of the fore tarsi is light rusty-brownish ; middle tarsi from the tip of the first joint black; hind tarsi entirely black. Cilia of the tegule pale yellowish. Wings hyaline, towards the fore margin with a faint brownish-gray tinge; the costa near the tip of the first longitudinal vein only very little stouter, but not thickened ; fourth longitudinal vein not broken. Hab. Illinois. (Le Baron.) Observation.—In order to distinguish D. socius from the very like D. brevimanus, it is only necessary to pay attention to the difference in the length and coloring of the fore tarsi and also to the different nature of the hairs on the under side of the hind femora. From D. subciliatus, nudus and splendidus, D. socius differs by its hind tibize, which are distinctly blackish at the tip, whereas in D. subciliatus and nudus they are only slightly infus- cated at the tip, and altogether yellow as far as the extreme tip in D. splendidus. From D. subciliatus and D. splendidus it further differs by the red coloring of the lower margin of the first joint of the antennz and by the hind femora of the ¢ which are not ciliated; from all three above named species it differs by the plain fore tarsi of the ¢. 14. BD. mudus,n.sp. % and 9.—Viridis, nitidus, coxis anticis pedi- busque flavis, apice tibiarum posticarum subfusco, antennis preter in- ferum articuli primi marginem tarsisque posticis nigris, ciliis oculorum inferioribus tegularumque ciliis flavicantibus. *%,. Tarsis anticis elongatis tenuibus, articulo ultimo dilatato atro, femori- bus posticis non ciliatis. ©. Pedibus simplicibus, tarsis anticis inde ab attiquld primi apice nigris. Green, bright ; fore coxe and feet yellow; tip of the hind tibiz brownish ; hind tarsi black; lower margin of the first joint of the black antenne red ; cilia of the inferior orbit and of the tegule yellowish. *,. Fore tarsi elongated, slender, their enlarged last joint black; hind femora not ciliated. Q. Feet plain; fore tarsi from the tip of the first joint blackened. Long. corp. 0.21—0.22: Long. al. 0.25. Male. Metallic-green, bright. Front metallic-green. . A. calcitrams Lorw. %.—Scutello nudo, pedibus totis pallide — flavicantibus, metatarso postico maris paulo incrassato et valde hirto. Scutellum bare; the whole feet pale-yellowish ; the first joint of the hind tarsi of the male somewhat thickened and covered with rough hair. Long. corp. 0.14—0.15. Long. al. 0.11. Syn. Argyra calcitrans Loew, Neue Beitr. VIII, 46, 3. Male. Face narrow, silvery-white. Thorax and proboscis black. Antenne black, third joint more blackish-brown; arista distinctly inserted before its end. Front silvery-white. Cilia of the upper orbit black, very short and delicate ; cilia of the inferior and lateral orbits white. Thorax shining green, covered with thick white dust, so as to make the ground color invisible in some directions. Scutellum also shining green, or blue-green, with less dust, and bare with the exception of the usual bristles. The ground color of the abdomen seems to be blackish-blue, but cannot be distinctly seen on account of the thick white dust which covers it; the second segment is yellowish and transparent, with a black- ish border on the posterior margin and with a blackish middle line, which is sometimes wanting; the third segment is of a simi- lar color, only the margin on the posterior border and the middle line are broader, though the latter is sometimes interrupted. The small lamellae of the hypopygium are brown. Coxe and feet white-yellowish ; fore coxe with delicate white little hairs and delicate black bristles ; middle cox on the outside with a black- ish spot; hind coxee scarcely a little blackened on the extreme ARGYRA. Tt basis. Fore and middle femora withont any longer hairs on the under side ; the hind femora have a row of black bristle-like hairs, inserted rather more on their hind side than upon the under side. Tarsi towards their end not infuscated, but only very little darker; the first joint of the fore tarsi is 13 the length of all the following joints taken together, on the under side with a row of delicate hairs; the first joint of the middle tarsi not quite as long as all the other joints together ; hind tarsi unusually short, the first joint not much shorter than al] the others, a little thickened, on the under side with rather long bristie-like hairs ; the second and third joints of the hind tarsi of about equal length. The cilia of the tegule, which have a blackish margin, are white-yellowish. Wings some- what tinged with yellowish-gray, with yellowish-brown veins ; the last segment of the fourth longitudinal vein is but gently inflected forward. - Hab. New York. (Osten-Sacken.) G. A. caliceata Lorw. ¢(?.—Scutello nudo, pedibus pallide flavis, tarsis posticis nigris. Scutellum bare, feet pale-yellow, with black hind tarsi. Long. corp. 0.16. Long. al. 0.15. Syn. Argyra calceata Loew, Neue Beitr. VIII, 47, 4. Female. Face, for a female, of moderate breadth, silvery- white. Palpi rather large, black, with almost silvery-white dust ; proboscis brownish-black. Antenne black; third joint small, with an acute angular tip; arista distinctly inserted before its end. Cilia on the upper orbit black, extremely short and delicate. Cilia of the lateral and inferior orbits white. Thorax shining green, in the vicinity of the shoulders rather thickly covered with white dust, so as to induce the belief that the males are altogether covered with silvery-white dust. Scutellum also shining green and with the exception of the usual bristles, bare. Ground color of the abdomen greenish-black ; the second, third and fourth seg-, ments yellow, with the exception of the extreme anterior margin, the posterior margin and a narrow, not always distinct middle line ; on the sides of the segments and towards the tip of the ab- domen there is some white dust. Coxe and feet pale-yellowish ; fore coxee with delicate whitish hair and with black bristles ; mid- dle cox with a gray spot on the outside; hind femora scarcely a little darker at the tip, hind tibie at the tip not of a dark color. 132 DIPTERA OF NORTH AMERICA. [PART cr. Tarsi comparatively long; fore tarsi scarcely infuscated towards the end, only the last joint brown, the first joint a little longer than the others taken together. Middle tarsi from the tip of the first joint strongly infuscated ; the four last joints together as long as the first one. Hind tarsi entirely black, the first joint a little shorter than the second, the following joints decreasing in length. The cilia of the tegule, which have a blackish border, are pale. Wings tinged more with brownish than yellowish-gray; veins rather dark brown; the last segment of the fourth longitudinal vein, before its middle, only slightly inflected forward. Hab. Middle States. (Osten-Sacken.) Observation.—It is impossible to mistake A. calceata for the female of one of the two preceding species for the following rea- SONS :-— 1. On account of the greater extent of yellow color upon the abdomen, which is not so extensive in the females of the species of Argyra as in the males. 2. On account of the black coloring of the whole hind tarsi. It is probable that the coloring of the abdomen of the male of this species resembles that of the male of Leucostola cingulata. B. Abdomen entirely cylindrical, without white lustre. 4%. A. cylindrica, n. sp. %.—Viridis, nitens, abdomine vix obso- letissime albido pollinoso, coxis anticis pedibusque flavis, femorum pos- ticorum apice, summo tibiarum posticarum apice, tarsis denique omni- bus inde ab articuli primi apice nigris. Shining-green, the abdomen has scarcely a trace of whitish dust; fore coxe and feet yellow; tip of the hind femora, tip of the hind tibie and all tarsi, with the exception of their root, black. Long. corp. 0.23. Long. al. 0.22. Metallic-green, and differing from most of the species of Ar- gyra by the cylindrical form of the abdomen and the almost entire absence of all dust. Face with a white reflection. Palpi and proboscis brownish-black ; the hair-like cilia of the inferior orbit pale-yellowish. Thorax and scutellum shining, the latter without hairs. . Abdomen entirely cylindrical, not stouter about the basis, metallic-green, without any transparent spots upon the anterior segments and covered with a thin, almost impercep- tible, grayish-white dust. Fore cox yellowish, with some very scattered black hairs, and, at the tip, with longer black bristles. SYNTORMON. 133 Middle and hind coxe blackish-brown with yellowish tip. Feet yellowish, tip of the hind femora brownish-black to a considerable extent. The black hairs on the feet are somewhat sparse and only of middle length; on the under side of the fore femora there are but a few black hairs of greater length; upon the under side of the middle femora they are in greater number; on the under side of the hind femora only those hairs which are near the tip have a somewhat greater length. Fore tibia with somewhat longer hairs on the under side, on the upper side with but two or three bristle-like hairs of greater length. The middle and hind tibiz with but few and very short little bristles; the extreme tip of the latter is infuscated. (Fore tarsi wanting.) Middle tarsi plain, black from the tip of the first joint ; the first joint somewhat longer than the four following together; on the under side with but two very short black little bristles; hind tarsi black ; the first joint up to the middle brownish-yellow. Tegule with a broad black margin, with pale-yellowish cilia. Wings hyaline, some- what tinged with brown, the-anal angle less protruding than in most of the other species; the neuration shows nothing unusual for the genus. Hab. Sitka. (Sahlberg.) Observation.—Although the imperfect state of the above de- scribed specimen did not afford ‘a thorough examination of the hairs upon the upper side of the first joint of the antenne, still I believe to have satisfied myself of their existence. Gen. XV. SENTORMON. The generic character is as follows: First joint of the antenne with hairs on the upper side; the second reaching on the inner side of the third in the shape of a thumb; third joint of the an- tenne elongated and pointed in the male and shorter in the fe- male; the position of the arista apical. Scutellum bare. The first joint of the hind tarsi without bristles and a little shorter than the second. The hypopygium small and imbedded, with very small, often not distinctly perceptible appendages. The next related genus is Synarthrus, the species of which differ from the species of Syntormon only by the absence of hair upon the first joint of the antenne. Although this character may appear trifling to those who have not studied the family of the 134 DIPTERA OF NORTH AMERICA. [PART IL. Dolichopodide carefully, nevertheless its observation is important, as it is of very great service for the specific distinction as well as for the generic location of such females of different species which resemble each other very closely. The name of the genus (from ovrropuow, I connect by inserted pins) has reference to the characteristic formation of the second joint of the antenne. As yet only European species of Syntormon have become known. Gen. XVI. SYWNARTHRUS. The following are the most important characters of this genus: The first joint of the antenne without hairs; the second reaching more or less on the inner side of the third, usually forming in the males a thumb-like projection, and in the females a more rounded lobe; the third joint of the antenne in the males elongated and pointed ; arista apical or so near the extreme tip of the antenne, as to be taken for such. Scutellum usually bare, first joint of the hind tarsi without.bristles. The hypopygium small, imbedded, with very small, often not distinctly perceptible appendages. That Synarthrus differs from Syntormon only by the absence of hair upon the first joint of the antenne, fas already been stated. Of the three species described below, two undoubtedly belong to the genus Synarthrus. This cannot be said with regard to the third species, Synarthrus barbatus. Its position in the genus Synarthrus can only be a temporary one, brought about by the difficulties of placing it into another genus. It is sufficiently dis- tinguished from the other species’ of Synarthrus by the peculiarity alone, that the second joint of the antennze encroaches only very “little on the inner side of the third. In its general appearance it approaches the species of Porphyrops very closely, so that I leave it undecided whether it would not be better located there. The size of the pulvilli of the fore tarsi betrays a relationship with Eutarsus and Diaphorus, the structure of the antenne, however, does not allow its location in these two genera. ‘To erect a new genus does not seem advisable, as the species shows close rela- tionship in various directions. The name Synarthrus (from oiv, together, and dpSpor, joint) has reference to the peculiar mode of connection between the second and the third joints of the antenne. SYNARTHRUS. 135 The species already known belong to Europe and to North America. Table for the determination of the Species. i/ Posterior margin of the pleurz yellow. 1 palmaris, nov. sp. ( Posterior margin of the pleure not yellow. - 2 Hind femora yellow. 2 cinereiventris Lw. ( Hind femora green. 3 barbatus Lw. Systematical arrangement of the Species. I. Lower half of the occiput only with the usual cilia. 1. palmaris, nov. sp. 2. cinereiventris Lw. II. Lower half of the occiput with a strong beard. 3. barbatus lw. Description of the Species. I. LOWER HALF OF THE OCCIPUT ONLY WITH THE USUAL CILIA. 1. 8S. palmaris,n.sp. % and 9.—Viridis, pleurarum margine pos- tico, coxis, pedibusque flavis. *. Tarsis intermediis apicem versus dilatatis. Q. Tarsis simplicibus. Green, the posterior margin of the pleure, coxz and feet yellow. *,. The middle tarsi towards their end enlarged. Q. Tarsi simple. Long. corp. 0.13. Long. al. 0.14. Male. It can be easily recognized by its striking resemblance to the European Syntormon tarsatus Fall. Rather dark bronze- green, little shining ; the abdomen usually rather copper-colored. Antenne black; first joint on the upper side entirely bare; the second with a long thumb-like projection which overlaps the inner side of;'the third; third joint rather long, pointed, very bubes- cent; the arista has not precisely an apical but a somewhat sub- apical position, as it is the case with Syntormon tarsatus. Face covered with whitish dust, narrow. Palpi and proboscis black. Front steel-blue. The delicate cilia on the inferior and lateral orbits pale. Scutellum of the same color as the upper side of the thorax, and beset, besides the usual bristles, with a few short hairs. Pleure grayish-green, their posterior margin yellowish. The sides of the abdomen near its basis somewhat yellowish and trans- parent; on the posterior margin of its first segment there are long 136 DIPTERA OF NORTH AMERICA. [PART It. black bristles, on the posterior margin of the other segments there are only very short bristles. Venter as far as the tip yellowish. Hlypopygium rounded, small, rather imbedded; its blackish ap- pendages very short and therefore not distinctly perceptible. Coxe and feet yellowish; fore coxe only at the tip with a few black bristles, otherwise in front with short and very delicate white hairs. The short hairs upon the feet are black ; under side of the fore femora glabrous; middle femora upon the under side with a row of short black bristles. Fore tibiz on the upper side with a dense row of black hairs, upon the first quarter of the hind side with a single very small black bristle. Middle and hind tibiz only with a few short black bristles ; the end of the latter is some- what thickened and of a brownish-black color. Fore tarsi plain, from the tip.of the first: joint blackened ; the first joint not quite as long as the other four taken together. The first joint of the middle tarsi nearly as long as the other four taken together, stalk- like, a little thicker at the end and of a whitish color; the second joint very much flattened, whitish, the apical margin bordered with black; the third and fourth joints also flattened, and, with the fifth joint, which is not flat, of a deep black color. Hind tarsi as far as the middle of the second joint brown, then black ; the first joint is a little stouter and shorter than the second and has upon the middle of its under side a black bristle which is a little curved backwards. ° Wings hyaline, tinged with brownish-gray ; the third and fourth longitudinal veins show towards their end a slight convergency. Female. The third jomt of the antennee rounded-oval, very much shorter than in the male; the second joint of the antenne overreaches the inner side of the third only by a rounded lobe. Face less dusty than in the male, very broad, by far not reaching the lower corner of the eye; its lower part is very convex and protrudes in the shape of a roof, whereby the mouth becomes very large. The black palpi considerably larger than in the male. Feet plain, the hind tibie not thickened at the end and only very slightly infuscated. Fore tarsi from the tip of the first joint gra- dually becoming more infuscated ; middle tarsi from the tip of the first joint blackened, though the root of the second joint is some- what paler; hind tarsi at the root brown, black towards the end. The little black bristles upon the under side of the middle femora are missing. The rest as in the male. Hab. Sitka. (Sahlberg.) SYNARTHRUS. ley Observation.—Syntormon tarsatus has upon the upper side of the first joint of the antenne, quite in the vicinity of the basis, a few almost imperceptible little hairs, which I am unable to per- ceive in the present species, so that I am compelled to locate it into the genus Synarthrus. It is further distinguished from Syn- tormon tarsatus by the shorter arista and by the broader wings, which are less narrow towards the root. Besides, in the male the tip of the hind tibiz is less thickened, the second joint of the mid- | dle tarsi is broader, of a whitish color, and has only at its tip a black margin, while in the male of Syntormon tarsatus it is less broad, yellowish upon the middle of the root and black upon the whole apical half. The relation which exists between Synarthrus palmaris and Syntormon tarsatus is exactly the same as that be- tween Synarthrus pallipes and Syntormon Zellert. 2. S. cimereiventris Lorw. 9.—Viridis, coxis anticis pedibusque flavis. Green, fore cox and feet yellow. Long. corp. 0.13. Long. al. 0.13. Syn. Synarthrus cinereiventris Lozw, Neue Beitr. VIII, 48, 1. Female. Shining metallic-green. Face very broad; the infe- rior portion protrudes considerable in the shape of a roof, so that the palpi are rather concealed and the mouth becomes unusually large; the blue-green ground color of the face is rather covered by a gray-whitish powder. Antenne black, rather large for a female; the second joint overreaches the inner side of the third with a broad lobe; the third joint is short, but very broad, beset with very short but distinct hair; the arista is distinctly longer than the antenne. The front in the middle is almost blackish- green, about the antenne steel-blue, on the upper corners rather violet and may possibly vary a little in its coloring. Cilia of the upper orbit black, those of the lateral and inferior orbits white. Thorax shining metallic-green, with very thin and almost imper- ceptible, nearly whitish, dust. Abdomen also shining metallic- green, on the lateral margin with but little perceptible whitish. powder. Venter whitish-gray. Fore coxe yellow, with delicate whitish hair and no black hairs or bristles. Middle and hind coxe blackish with yellow tip, the former green on the front side, and, like the fore coxe, beset with delicate whitish little hairs. Feet yellow; tarsi gradually dark brown towards their end, but 153 DIPTERA OF NORTH AMERICA. [ PART II. so that the first joint, with the exception of its tip, is dark yellow, and the second joint, with the exception of its tip, is brownish- _ yellow. The hind tarsi are visibly shorter than the hind tibie, and the first joint is longer than the second. The yellowish tegu- le have a narrow dark-brown margin and yellowish cilia, which - in some directions assume a very dark color. Halteres yellowish. Wings grayish; the last segment of the fourth longitudinal vein not distinctly inflected ; posterior transverse vein steep. Hab. Middle States. (Osten-Sacken.) | II. LOWER PART OF THE OCCIPUT WITH A STRONG BEARD. De Ss. barbatus Lorw. %.—Viridis, pedibus flavis, femoribus posticis viridibus. . Green, feet yellow, hind femora green. Long. corp. 0.12—0.13. Long. al. 0.12. Syn. Synarthrus barbatus Lorw, Neue Beitr. VIII, 48, 2. Shining metallic-green. Face green, and dull on account of a moderately thick yellowish-white dust, which however does not conceal the ground color. Palpi a little larger than those of the males of Synarthrus in general; they have also a more disengaged position, a bright yellow color, and are beset with a few black little hairs. Antenne black; the second joint reaching only a little on the inside of the chee. almost of transverse form; the rather strikingly hairy third joint is broad only about the bask and becomes elongated into a narrow and very long point; the arista is entirely apical and only half the length of the third joint. Front metallic-green, little shining. Cilia of the upper orbit black, short and delicate; cilia of the lateral and inferior orbits very long, white ; they form with the hair on the lower part of the occiput a sii beard. Thorax and scutellum metallic-green, the former less shining on account of a cover of pale dust, the lat- ter sometimes more bluish-green. Abdomen metallic-green. The last segments assume in some directions a rather black-green color. The small imbedded hypopygium black ; its outer append- ages have the form of small lamella and are of a brownish color ; the inner appendages are not distinctly perceptible. Fore coxe blackish, on the front side greenish-blue; their delicate hairs are principally white, but towards the basis of the cox there are also some black hairs; on the tip are black bristles. Middle and hind SYNARTIRUS—SYSTENUS. 139 cox black; the former with black hairs and bristles. Fore feet yel- low ; femora incrassated towards their basis, on the upper side with a narrow brownish-black longitudinal stripe, reaching to the ex- treme tip; the under side is sparsely fringed with short black hairs, and where these end, there are three black bristles turned somewhat backwards. Fore tibiz covered with thick, rather coarse, but short hairs. Fore tarsi from the tip of the first joint, which is about as long as the others, strongly infuscated. The first and second joints beset on the under side with short bristle- like hairs; pulvilli rather large. Middle feet yellow; femora thickened about their basis; the tibiz have besides the bristle at the tip only one on the upper side, not far from the basis; the tarsi are very much infuscated from the tip of the second joint. Hind femora metallic-green with yellow tip, at the end of the under side with a few black bristles. Hind tibiz yellow, only’ sparsely bristled. Hind tarsi yellow at the basis, from the tip of the first joint black-brown; their joints decrease in length, the first considerably longer than the second. The cilia of the whitish tegule show in most directions a brownish-black coloring, while in some they appear with a yellowish lustre. Halteres yellowish. Wings grayish hyaline with brownish-black veins; the posterior _ transverse vein is straight and has a very steep position; the last segment of the fourth longitudinal vein shows upon its first third an almost imperceptible flexure, otherwise it very little approaches the third longitudinal vein, ruus parallel with it and terminates precisely in the apex of the wing. Hab. Middle States. (Osten-Sacken. ) Gen. XVII. SYSTENUS. This genus, hitherto confined to European species only, may be characterized in the following manner: First joint of the antenne without hairs on the upper side; the second joint transverse; the third large, longer in the male than in the female, in both sexes broad at the basis, ending into a point, distinctly hairy; arista completely apical. Feet rather slender, in both sexes plain and beset only with very few and short bristles. The first joint of the hind tarsi without bristles and scarcely half the length of the -second. The sixth longitudinal vein of the wings distinct. The abdomen of the male towards the tip and laterally much com- 14° DIPTERA OF NORTH AMERICA. [ PART II. pressed, its last segment narrow. The basal portion of the entirely disengaged and inflected hypopygium forms a long peduncle; the outer appendages are rather filiform and whitish, the inner appendages also. The last segment of the fourth longi- tudinal vein with more or less flexure. . The name of the genus (from ov», together, and orevds, narrow) has reference to the very pointed shape of the third joint of the antenne, which is peculiar to both sexes. Gen. XVIII. RHAPHIUM. The first joint of the antenne has no hairs on the upper side; the second is transverse ; the third glabrous, very narrow, in both sexes very much elongated, though in the male more so than in the female. Arista entirely apical, bare ; its first joint somewhat elongated in the male. Scutellum glabrous. Hypopygium small, rounded, rather imbedded ; its outer appendages more filiform than lamelliform; the inner appendages small; the first joint of the hind tarsi without bristles. The genus Rhaphium stands in next relation to the genera Porphyrops and Xiphandrium. With the species of Porphyrops it shares the larger size, the greater number of bristles on the . feet, the broader wings, less narrow towards the basis. With the species of Xiphandrium it has in common the great elongation of the second joint of the antenne, the lesser density of hair on — the occiput, and the shorter hair upon the coxe and feet, also that the last segment of the fourth longitudinal vein is less inflected. From both these genera, however, Rhaphium is distinguished by the somewhat longer first joint of the antenne, which, particularly in the male, is rather swollen; by the great narrowness and the glabrousness of the third joint, which is uncommonly elongated not only in the male but also in the female; by the glabrousness of the arista, and finally, by the more narrow and mores pointed palpi of the female. The other genera most closely approaching Rhaphium, as Systenus, Synarthrus and Smiliotus, cannot be easily confounded with it, the hypopygium of the male in the \spe- cies of Systenus being very much pedunculated, the second joint of the antennz in the species of Synarthrus reaching over the third, and the abdomen in Smiliotus having only five segments. ti RHAPHIUM—XIPHANDRIUM. 141 The name of the genus (from fag.ov, small needle) has reference to the shape of the antennee, which distinguishes it. Only a single European and one North American species, de- scribed below, are known at present. I. R. lugubre Lozrw. 9Q.—Ex viridi nigrum, nitens, pedibus nigris, anteriorum tibiis intermediorumque femoribus luteis. Greenish-black, shining; feet black ; the four anterior tibize and the middle femora dusky yellow. Long. corp. 0.16. Long. al. 0.16. Sy. Rhaphium lugubre Loew, Neue Beitr. VIII, 49, 1. Of a bright metallic, but very dark greenish-black color. Face moderately broad, with a bright lustre of silvery-white powder upon black ground. Palpi black with white powder. The black antennee very long, narrow and glabrous; the apical bristle short , and bare. Front shining black. Cilia of the upper orbit black, delicate, short; cilia of the lateral and inferior orbits white. Thorax bright, with an almost imperceptible gray-whitish dust. The scutellum has no hair with the exception of the usual bristles. Abdomen bright, only on the lateral margin with distinct white powder ; the hair upon it is black. Coxe black with white dust ; the front side of the fore coxse with white hair and black bristles. ' Anterior femora black with luteous tip; fore tibize luteous, only with two bristles on the upper side ; fore tarsi black, the first joint as far as the tip, luteous. Middle feet luteous, tarsi from the tip of the first joint blackened. Hind feet entirely black, only the knees yellow; the first joint of the tarsi scarcely a little longer than the second. Cilia of the brown tegule whitish. Wings blackish, on the fore margin and along the veins darker; the last segment of the fourth longitudinal vein only in the middle gently inflected forward. Hab. Carolina. Gen. XIX. KIPHANDRIUM. The genus Xiphandrium comprises small species, of slender form, with little hair. The first joint of the antenne has no hair on the upper side; the second is of a transverse form, the third rather narrow, in the male very much elongated and in the female much shorter; the hairs upon it are distinct, especially on the under side. Arista entirely apical, comparatively short, with 142 DIPTERA OF NORTIZ AMERICA. [PART II. scarcely perceptible short pubescence. The lower part of the occiput only with the usual fringe of cilia. Scutellum without hair. Coxe and feet comparatively bare, the latter with very few bristles; the first joint of the hind tarsi without bristles. Wings not very broad, somewhat narrowed towards the basis; the last segment of the fourth longitudinal vein little inflected ; hypo- pygium small, rounded, rather imbedded, its outer appendages more filiform than lamelliform; the inner appendages small. The next related genera are Rhaphium and Porphyrops. The characters of the -genus Rhaphium have already been described. The species of Xiphandrium differ from the species of Porphyrops by their smaller size, more slender form, less hair, especially on the lower part of the occiput and on the coxe; the third joint of the antenne of the males is more elongated, more distinctly hairy, particularly on the whole lower side; the arista is beset with a comparatively short but easily perceptible pubescence ; the wings are less broad and towards their basis still narrower. It cannot be mistaken for the genera Systenus, Synarthrus and Smiliotus, as they differ from Xvphandrium and Rhaphium by the same distinctive marks. The name (from & 0s, sword, and drzp, man) has been given to this genus on account of the sword-shaped antennz of the male. Out of Europe, no species of Xvphandrium are as yet known. I have a female from North America, which probably belongs to this genus. As it has lost its antenne, its systematical location could not be ascertained. Gen. XX. PORPHYROPS. The genus Porphyrops comprises species of at least middle size, rather stout shape and very hairy. The first joint of the antenne has no hairs on the upper side; the second is transverse ; the third is moderately elongated in the male and shorter in the female; the hairs upon it are very short and the whole under side (with the exception of a few species) is entirely bare. Arista altogether apical with an almost imperceptible and very short pubescence. The under side of the occiput more or less densely fringed. Scutellum without hairs. Coxe and feet with rather much hair and bristles. First joint of the hind tarsi without bristles. Wings comparatively broad, towards the basis only a PORPHYROPS. 143 little narrower; the last segment of the fourth longitudinal vein moderately inflected. Hypopygium small, rounded, rather im- bedded, its outer appendages almost in all the species more fili- form than lamelliform ; the outer appendages small. With regard to the mutual relation of the three kindred genera, namely, Rhaphium, Xiphandrium and Porphyrops, all the re- quired information has already been furnished, so that a repetition of their distinctions is not necessary. I have vindicated the name of Porphyrops for this genus in the fifth volume of the Neue Beitrige. An entirely unfounded oppositions had been raised against it. The following are the reasons by which I have been governed with relation to the name Porphyrops. Meigen, in the fourth volume of his works, has taken a wider view of the genus Porphyrops and divided it into three sections: 1. With a subapical arista. 2. With an apical arista; and, 3. With an arista inserted dorsally on the third joint, near the basis. In his seventh volume he adopts the genus Argyra, which M. Macquart had in the meantime established for the first of the three divisions ; the third division he unites with Medeterus; and for the only remaining second division, which principally contains species of the present genus, he retains the name of Porphyrops; at the same time he unites with them the species of his genus Rhaphium (that is the genera Rhaphium and Xiphandrium in the sense adopted above). As I cannot agree with this reunion, I am com- pelled to retain the name of Porphyrops for the genus, which embraces most of the species contained in Meigen’s second division and this is the present genus. The name Porphyrops (from zoppipa, scarlet, and 3), face) has reference to the beautiful scarlet color which is peculiar to the eyes of many species, especially the males. The hitherto known species of Porphyrops are distributed all over Asia Minor, Europe, and North America. Table for the determination of the Species. haem black. 1 melampus Zw. Feet yellow. ’ 2 { All the coxe black. 2 nigricoxa Lw. Fore cox yellow. 3 { Fore coxe not blackened at the basis. 3 fumipennis Lw. Fore coxe blackened at the basis. 4 rotundiceps L/w. 144 DIPTERA OF NORTH AMERICA. [PART Il. Description of the Species. i. P.melampus Lorw. ~% and 9.—Pedibus atris, alis nigricantibus. Feet black, wings blackish. Long. corp. 0.17—0.18. Long. al. 0.14— 0.15.° Syn. Porphyrops melampus Loew, Neue Beitr. VIII, 50, 1. Male. Metallic blackish-green. Face very narrow, with white dust. Palpi black with white dust. Antenne black; third joint rather long and pointed; arista more than half the length of the third joint. Front black-green, with white dust. Cilia of the upper orbit black, those of the inferior snow-white. Upper side of the thorax shining, only on the anterior and lateral margin with more distinct white dust; on the former the beginning of two darker colored lines is perceptible. The scutellum has no hair besides the usual bristles. The bright and dark-green abdomen has scarcely a trace of white dust ; its last seement is almost black. The hypopygium is a little larger than in most of the other spe- cies of this genus, bright black; the outer appendages are ex- tremely small black lamelle fringed with black hair; the-brown interior appendages are also small, turned a little upwards at the end, but pointed and upon the middle of the lower side fringed with afew hairs. The hair upon the abdomen is black, only on the lateral margin of the anterior segments and upon the venter whitish. Coxe black, with a rather thick white powder, the fore and middle coxee with considerable white pubescence and without any black bristles. Feet black; femora with a trace of blackish- green lustre; the tip of the trochanter, the tip of the knee, also the extreme tip of the fore and middle tibia brownish-yellow ; the first joint of the fore tarsi a little longer than the three following together, at the end of the under side dilated almost in the shape of a tooth; otherwise the feet have no particular distinction. The cilia of the pale-yellowish tegule have whitish hair. Halteres pale-yellowish. Wings blackish, in the vicinity of the second half of the anterior margin rather black; the last segment of the fourth longitudinal vein only very little inflected forward in the middle. } Female. The only specimen which I have before me, strikingly differs from the described male in the color of the body ; as all the other characters coincide perfectly with those of the male, I have not the least doubt that both belong together and consider the PORPHYROPS. 145 (lifference in the color as only accidental, as it so often occurs in the Dolichopodide. Face moderately broad, with silvery-white dust. Palpi black with white dust. Antenne short, the third joint small and ovate; arista three times the length of the anten- ~ ne. Front blue with thin white dust. Upper side of the thorax steel-blue, upon the middle and towards the hind margin more violet. The steel-blue scutellum upon its middle is also of a vio- let color. The abdomen is dark metallic-green, its last segment rather black-green at the basis, otherwise bright steel-blue. The hairs on the fore coxe are like those of the male, only less dense and shorter ; the hair on the middle coxe is also whitish, the weak bristles in the vicinity of its tip are, however, black. The wings are the same as those of the males, only the blackening of the second part of the fore margin is stronger and the fourth longitu- dinal vein with the posterior transverse vein have a darker seam. The remainder like in the male. Hab. District Columbia. (Osten-Sacken.) 2. P. migricoxa Lorw. ©.—Pedibus flavis, coxis omnibus et totis nigris. Feet yellow, all the coxe entirely black. Long. corp. 0.22. Long. al. 0.23. Syx. Porphyrops nigricoxa Loew, Neue Beitr. VIII, 51, 2. Female. Metallic-green, front, thorax and scutellum very cop- pery. Face with yellowish-gray dust ; the separation between its upper and lower part is particularly striking. Palpi compara- tively small, black with yellowish-gray dust ; antenne black ; third joint ovate; arista 1$ the length of the antenne. Front with thin yellowish-gray dust. Cilia on the upper orbit black, on the lateral and inferior orbits white. All the coxe entirely black, with gray dust and whitish hair; at the end of the fore and middle cox there are no black bristles. Feet yellow, apical half of the hind femora black, the last third of the hind tibie and the hind tarsi altogether are of the same color; middle and fore tarsi strongly infuscated from the root and towards the end black. Cilia of the yellowish tegule white. Halteres pale-yellowish. Wings gray, on the fore margin more brownish gray; the last segment of the fourth longitudinal vein, beyond the middle, gently inflected forward. Hab. Maryland. (Qsten-Sacken.) 10 146 DIPTERA OF NORTH AMERICA. [PART IL. 3. P. fummipennis Lorw. ©.—Pedibus flavis, coxis anticis totis concoloribus. Feet with the fore coxe altogether yellow. Long. corp. 0.18. Long. al. 0.17—0.18. : Syn. Porphyrops fumipennis Loew, Neue Beitr. VIII, 51, 3. Female. Bright metallic-green. Face with pale yellowish- gray dust. Palpi black, with yellowish-gray dust. Antenne black; the third joint.small, rounded-ovate ; arista at least three times the length of the antennew. Front blue-green, with a pale yellowish-gray dust. Cilia of the upper orbit black, those of the lateral and inferior white. Thorax with a thin but rather distinct grayish-yellow dust. Fore coxe yellowish with white hair; on their tips among the white hairs there are a few black bristles, not easily perceived. Middle and hind coxe blackish with yel- lowish tip; the front side of the middle coxe is clothed with white hair and towards the tip with a few black bristles; hind femora blackish-brown at the tip; fore and middle tarsi infuscated, black- ened towards the end; the last third of the hind tibie and the hind tarsi black. Cilia of the pale-yellowish tegule whitish ; halteres pale-yellowish. Wings tinged with brownish-gray ; the last segment of the fourth longitudinal vein gently inflected for- ward upon its middle. Hab. Middle States. (Osten-Sacken.) 4. P. rotumdiceps Lozrw. %.—Pedibus flavis, coxis anticis conco- loribus, basim versus nigris. i Feet and fore coxe yellow, the latter in the vicinity of the root, black. Long. corp. 0.16. Long. al. 0.16. Syn. Porphyrops rotundiceps Lozrw, Neue Beitr. VIII, 51, 4. Male. Bright metallic green. Face very narrow, with silvery- white dust, palpi black with pale dust. Antenne black; the third joint not very long for a male, rather rounded at the end; arista about as long as the antenne. Front metallic green. Cilia of the upper orbit black, of the lateral and of the inferior orbits white. Upper side of the thorax bright, with very indis- tinct white-grayish dust. Scutellum in part steel-blue. Abdo- men bright metallic green; in the vicinity of the lateral margin with rather distinct whitish dust; the narrow last segment rather steel-blue; the hair black, on the lateral margin and upon the SMILIOTUS, 147 venter whitish. The small hypopygium black; the exterior ap- pendages are of a dusky gray-yellowish color, comparatively long, fork-shaped and split into a shorter and a much longer internal lobe; the hornlike interior appendages are black and pointed. The yellowish fore coxe are upon their whole basal half of a brownish-black color, and fringed on the front side with long whitish hairs. There are no black bristles upon them. Middle coxe blackish with yellowish tip, the latter with a considerable black thorn, which seems to be composed of several contiguous bristles. Hind coxee of the same color as the middle coxe. Feet yellow ; hind femora almost upon the whole apical half black; hind tibiz although strong, but not incrassated, their last third black. Fore and middle tarsi somewhat infuseated, their end and the tip of their first joint more dark brown; the first joint of the fore tarsi of the usual form, the hind tarsi black. Cilia of the pale- yellowish tegule whitish. Wings tinged with gray, a little darker ’ upon the last part of their anterior margin; the last segment of the fourth longitudinal vein gently inflected forward upon its middle. Hab. District Columbia. (Osten-Sacken. ) Gen. XXI. SMILIOTUS. Characters. Face in both sexes broad. Palpi large, concealing the proboscis. The antennz in both sexes of a similar structure ; the first joint on the upper side without hairs ; the second of the usual transverse form; the third joint of different length in dif- ferent species, on the under side nearly excised from the root to the tip; the arista entirely apical, the first joint short and stout, the second, however, long, very slender, particularly towards the tip. Scutellum without hair. The abdomen of the male shows only five segments, while there are six in the related genera. The small rounded hypopygium is imbedded and has only very short appendages. All the tarsi are short, especially the hind tarsi, the first joint of which has no bristles; the pulvilli of the fore tarsi of the male are enlarged. The wings are elongated, of rather equal breadth, and have a distinctly protruding anal angle ; the last segment of the fourth longitudinal vein is somewhat in- flected, ends beyond the tip of the wing and runs upon its middle over a large but flat impression. © 148 DIPTERA OF NORTH AMERICA. [PART IL. This genus has been established by Mr. Haliday, and, in con- sideration of the almost swordlike form of the antenne of the species which became first known, was called Machzrium (from uazovea, the sword). As this same name has already been used for a genus of plants, I have thought fit to abandon it and to substi- tute the name of Smlrotus (from ourrwrds, the pruning-knife, because the third joint of the antenne in the two known species has the form of a pruning-knife). The two known species belong to the European fauna. Gen. XXII. APHROSYLUS. The known species of Aphrosylus agree in the following, in part rather striking peculiarities which constitute the character of this genus. The first joint of the antennz without hair, the second of the usual transverse form, the third tapering at the tip; the arista entirely apical. The face narrowed above, espe- cially in the male. The proboscis turned towards the breast. Palpi disengaged, hanging downward, in the male larger than in the female. The abdomen of the male shows six segments; the short and rounded hypopygium ends it in the shape of a knob; its exterior appendages are elongated, parallel lamelle, fringed with rather long hair. The female abdomen has only five seg- ments. Wings of rather equal breadth; the posterior transverse vein is less distant from the margin of the wing, than its own leneth ; the end of the fourth longitudinal vein is parallel with the third. Feet with rather coarse bristles; the first joint of all the tarsi is much longer than the second; the first joints of the hind tarsi without bristles. The structure of the proboscis and the position of the palpi distinguish the species of Aphrosylus sufficiently from all the other genera of Dolichopodidx. Hitherto only European species . have been described. The name of the genus (from agpos, the froth, and ovade, I rob) has reference to the habit of these species to pursue their prey along the shores of a surging sea. Gen. XXII. THINOPHILUS. Characters. The face in both sexes broad, not reaching as far as the lower eye-corner, and ending below at an obtuse angie. THINOPHILUS—PEODES. 149 Palpi in both sexes large, reposing upon the proboscis. Antenne very short; the first joint without hair, the second short, trans- verse, longer above than below; the third joint circular, the bare arista dorsal. Wings of equal breadth; the posterior transverse vein is distant from the margin of the wing more than its own length; the last segment of the fourth longitudinal vein is rather parallel with the third. The abdomen of the male has six seg- ments ; the hypopygium small, rather imbedded, and somewhat turned inside; its exterior appendages are narrow, parallel lamella. The abdomen of the female shows five segments. Femora rather strong, the first joint of the hind tarsi without bristles. The species of Thinophilus are easily distinguished from the species of Diostracus by the absence of hair upon the first joint of the antenne; from the species of Peodes they differ by the structure of the face and of the hypopygium. They live principally along the shores of the sea, whence their name (from Sis, down, sand hill, and aos, friend). As yet only European species have been made known. Gen. XXIV. PEODES. Characters. Face not reaching as far as the lower corner of the eye, rather narrow in both sexes, though a little broader in the female, and more enlarged below; the lower margin is straight. Palpi in the female considerably larger than those of the male and in both sexes reposing upon the proboscis. Antenne very short; the first joint without hairs; the second short, transverse; the third joint rounded; arista dorsal, only with a short pubes- cence. Wings of uniform breadth; the posterior transverse vein is removed from the margin of the wing more than its own length; the last segment of the fourth longitudinal vein parallel with the third. The abdomen of the male has six segments; the short, stout hypopygium is not imbedded, but disengaged and a little inflected; its exterior appendages are two small parallel lamelle alongside of each other and with long hair; the interior appendages form a remarkably large curved forceps. The abdo- men of the female shows five segments. The femora are rather strong; the first joint of the hind tarsi has no bristles. Peodes is closely related only to Thinophilus ; the differences become evident when the characters of both genera are compared. 150 DIPTERA OF NORTH AMERICA. [PARY 11. The name of the genus (from meddys, provided with a large penis) has reference to one of its most striking characters. Only one Huropean species has as yet been made known. Gen. XXV. NEMATOPROCTUS. Characters. Antenne short ; first joint without hair; second joint short, transverse; third joint small, in the male not larger than in the female, rounded ; the rather long arista entirely dor- sal. The face, much narrower in the male than in the female, does not reach as far as the inferior corner of the eye. Palpi re- posing upon the proboscis, those of the female much larger than those of the male. Front of equal breadth. The lower part of the occiput distinctly bearded. Hyes very hairy, especially towards the lower corner. Scutellum not hairy. The abdomen of the male has six segments; the small rounded, and a little im- bedded, hypopygium is at its tip; the exterior appendages are long and filiform, the interior appendages very short and usually not distinetly perceptible. The female abdomen shows five segments. Wings a little narrowed towards the basis, the first longitudinal vein not elongated ; the posterior transverse vein distant from the margin of the wing by more than its own length; the last seement of the fourth longitudinal vein very gently inflected and towards the end parallel with the third. Feet rather strong; pulvilli of the fore tarsi not enlarged; the first joint of the hind tarsi without bristles. The species of Nematoproctus mostly resemble in their habitus the species of Porphyrops ; they differ from them, however, by an altogether different structure of the antenne; the third joint of the male being also very short and the position of the arista com- pletely dorsal. They are less closely related to the species of Argyra, to which they were formerly reckoned, as the first joint of the antennee is without hairs, the third joint of the male is not en- larged, but as small as that of the female, the arista not subapical but entirely dorsal, the first longitudinal vein of the wings not elongated, further, the exterior appendages of the hypopygium have not the shape of short lamella, but of long threads. The species of Nematoproctus agree with the species ef Leucostola in the glabrousness of the first joint of the antennz ; otherwise they LEUCOSTOLA. Lb differ from them precisely in the same manner as from the species Argyra. The name of the genus (from rua, the thread, and apwxros, po- dex) has reference to the thread-like form of the exterior ap- pendages of the hypopygium. The species hitherto known are all Huropean. . Gen. XXVI. LEUCOSTOLA. The species of Zeucostola, like those of Argyra, have usually upon the abdomen, and often also upon the thorax, a thick bril- liant ‘silvery dust, which renders them easy to recognize. The first joint of the antenne is entirely hairless, the second is trans- verse, the third bare, rather large in the male; the apparently bare and distinctly two-jointed arista is very near the tip of the antenne. Wings broad, the posterior angle rather protruding ; the first longitudinal vein is farther from the margin of the wing than in most of the other genera, and is also much longer than usual; the fourth longitudinal vein is inflected forward before the middle of its last segment, thence, however, again parallel with the third ; the posterior transverse vein is not approximated to the margin of the wing. The first joint of the hind tarsi has no bristles. Hypopygium small, imbedded; its exterior appendages . are two small narrow lamelle, bent downward; the interior ap- pendages are of rather simple structure, and often not distinctly visible. The close relationship of the genus Leucostola to that of Argyra can be easily perceived by a comparison of their characters. There is scarcely any difference between them, but that the first joint of the antenne of Leucostola is entirely without any hair, while in Argyra it is distinctly covered with hair. The name of the genus (from aevxos, white, and svoay, dress) has reference to the beautiful silvery lustre which covers the abdomen and sometimes also the thorax of most of these species. The known species belong in part to Europe and in part to America. 152 DIPTERA OF NORTH AMERICA. [PART $I. 1. L. cimgulata Lorw. %.—Viridis, lete splendens, abdomine ron pollinoso, cingulis flavis. Green, brightly shining, abdomen without white dust and with yellow bands. Long. corp. 0.19. Long. al. 016. Syn. Leucostola cingulata Lozw, Neue Beitr. VIII, 53, 1. Male. Face very narrow, silvery-white. Palpi snow-white. Proboscis brownish-black. Antenne black; the third joint black-brown ; the arista inserted close to its tip. Front black with silvery-white dust. Cilia of the upper orbit black, extremely short and delicate; cilia of the inferior and lateral orbits snow- white. Thorax metallic green, very bright, dusted only on the lateral margin. Scutellum of the same color, without hair, besides the usual bristles. Abdomen withott any white dust; the first segment mostly black; the second yellowish, transparent, with metallic black border on the posterior margin and with an indis- tinct blackish spot near the middle of the anterior margin; third segment also yellowish, transparent, and at the basis with a rather broad violet-black transverse stripe, bisinuated on the hind side, and with a narrow blackish-green border on the posterior margin ; the coloring of the fourth segment of the abdomen is the same, but the bands on the fore-margin and the posterior border are broader, so that the yellow part of the segment has the appear- ance of being divided into two spots; the fifth segment has no yellow color, but is violet-black near its basis and black-green towards the tip. The same color prevails on the small hypopy- gium, the extremely small lamelle of which are brownish. The rather long but not very coarse hair upon the abdomen is chiefly black, only upon the fore part of the first segment and upon the venter it is yellow-whitish. Coxe and feet pale-yellowish ; fore coxee with white hair and yellowish-white little bristles. Middle and hind cox near tHe basis a little blackened and also fringed with pale hairs and bristles. Femora slender, the hind ones slightly infuscated at the tip on the upper side. The hair upon the femora is blackish on the upper side and near the tip, whitish near the basis and on the under side; the very delicate whitish hair on the under side of the fore and middle femora is rather long. Fore tibize without any bristles; middle and hind tibize only with very few delicate and short bristles. Fore and middle tarsi slen- der, but not very long; the first joint about as long as the others EUTARSUS. 153 taken together. The first joint of the hind tarsi is shorter than the second and a little stouter, especially towards the tip; it is fringed with the usual short hair, which is however unusually dense upon the latter part of the under side. Cilia of the black margined tegule yellowish-white. Wings short and broad; the posterior transverse vein strikingly far distant from the margin of the wing; the last segment of the fourth longitudinal vein be- fore its middle gently inflected forward. Hab. District Columbia. (Osten-Sacken. ) Observation.—A rather badly preserved female, which I pos- sess, I suppose to be that of Leucostola cingulata ; it shows, how- ever, some differences, so that it may belong to some other closely related species. It differs from the above described male by the following characters: The face is comparatively broad and covered with a dense glittering silvery-white powder. The white palpi are larger than those of the male. The third joint of the antenne is very short; the position of the arista almost apical. The ab- domen is yellow with the exception of the last segment which is of a metallic-green color, shows however, when looked upon in an oblique direttion, an indistinct greenish lustre; its penultimate and antepenultimate incisures are greenish-black towards the lateral margin. The posterior margin of the pleure is not gray, but yellow. Among the whitish hair of the fore cox there are a few light- brown bristles, which, in a certain direction, have a black appear- ance. The tip of the hind femora is not darker and the first joint of the hind tarsi is of the usual plain structure, however compara- tively of the same length as that of the described males. Other- wise it coincides with it perfectly. The only character which makes it doubtful whether they belong together is the yellow color on the hind margin of the pleure in the female. Hab. District Columbia. (Osten-Sacken. ) Gen. XXVII. EUTARSUS. Characters, Face narrow, especially in the male; a little broader upwards. Palpi very small. The first joint of the an- tenne without hair, the second much overreaching the third; the third rounded ; the arjsta dorsal, though rather closely approxi- mated to the tip of the third joint, distinctly two-jointed. The elongated, cylindrical abdomen of the male consists of six seg- 154 DIPTERA OF NORTH AMERICA. [ PART II. ments; the hypopygium is very small, entirely imbedded and without bristles ; its appendages are extremely small, almost com- pletely hidden. The female abdomen shows only five segments. Feet rather long, moderately bristly ; the first joint of the hind tarsi without bristles, much shorter than the second; the pulvilli on the fore tarsi of the male are enlarged, but not elongated. Wings of rather uniform breadth or narrower towards the root; the first longitudinal vein not elongated; the last segment of the fourth longitudinal vein though somewhat inflected, still rather parallel with the third. Hutarsus appears to be nearer related to Diaphorus than to any other genus. ‘The striking smallness of the palpi, the face narrowed below, the hypopygium covered with but delicate hairs, the very small and almost completely con- cealed appendages of the hypopygium and the not elongated pul- villi of the fore tarsi in the male distinguish Hutarsus from Diaphorus sufficiently. From Nematoproctus, whose exterior appendages of the hypopygium are long threads covered with hair, Huéarsus is distinguished by the small and concealed ap- pendages of the hypopygium. The species of Saucropus cannot be confounded with the species of Hutarsus on account of the en- tirely disengaged hypopygium. The genus has been founded upon the well known European Eutarsus aulicus Meig. The name (from «3, handsome, and zapods, foot) has reference to the structure of the feet of the male. As yet no North American species is known to me, but I know a species from Venezuela, the hind tarsi of the male of which have a remarkable structure, and of which I furnish a description. i. E. eques, n. sp. %.—Chalybeus, modice nitens, abdominis ex eneo nigri maculis lateralibus, ventre pedibusque flavis, femoribus pos- ticis supra tibiisque posticis totis fuscis, tarsis anterioribus preter basim, posticis totis nigris, articulo horum primo brevissimo, quarto in aculeum producto. Steel-blue, moderately shining; lateral spots of the bronze-black abdomen, venter and feet yellow; upper side of the hind femora and the whole hind tibie brown; the four anterior tarsi with the exception of the root, and the whole hind tarsi black; the first joint of the latter very short, the fourth joint produced into a point. Long. corp. 0.27. Long. al. 0.26. ; * Male. Front shining steel-blue, not very broad, not excavated on the vertex. Antenne only of moderate length, black; the EUTARSUS. 155 narrow and a little elongated first joint is entirely bare on the upper side, on the lower edge of a rather distinctly reddish-yellow color; the third joint is short ovate ; the arista is inserted upon the back of the third joint, nearer to its basis than it is the case with Hutarsus aulicus. The face is very narrow immediately below the antenne, and grows more and more so till it becomes cuneiform, so that the large eyes are entirely contiguous on a large extent. Palpi very small; proboscis rather small. Thorax steel- blue or violet, little shining, upon the shoulders more blue-green and more densely covered with dust; the extreme corner of the shoulder brownish. Scutellum of the same color as the upper side of the thorax and with two bristles. Metathorax and pleurze black-green, the latter with whitish dust and a yellow hind mar- gin. Abdomen cylindrical, blackish bronze-colored; the second segment has near the basis a narrow yellow transverse stripe, which is somewhat dilated near the lateral margin; and upon the hind corners a large yellow spot; there are similar spots, but diminishing in size, upon the other segments. The small hypo- pygium is rounded and rather imbedded; its appendages are short, indistinct lamelle. The short hair upon the abdomen is black ; longer black bristles only on the hind margin of the first segment. Coxe and feet yellow; fore coxee with pale hair, at the tip only with a few thin black little bristles ; middle coxee with a large black spot, which covers about three-quarters of their outer side; the hind coxe with a small blackish spot. The hind femora on the upper half of their hind side blackish-brown ; fore and mid- dle tibiz only at the extreme tip slightly infuscated; the hind tibix totally black-brown. The fore tibiz are without bristles ; the middle and hind tibiz are but sparsely beset with short bris- tles. Fore and middle tarsi from the tip of the first joint black- brown, plain; the first joint of the fore tarsi is somewhat shorter than the following taken together, the first joint of the middle tarsi longer than the others taken together. The hind tarsi are black, very much shorter than the hind tibie and of a very peculiar struc- ture; the first joint is remarkably shortened, the second 44 the size and the third 23 the size of the first ; the fourth joint has only the length of the first, its end, however, is produced into a stout thorn, so that with it this joint is not much shorter than the third; the fifth joint is not at the end of the fourth, but attached on its under side at the place where the fourth joint begins to be pointed ; 156 DIPTERA OF NORTH AMERICA. [PART IT. on both tarsi it is rather singularly at right angles with the fourth joint, is somewhat longer than the third joint and has the form of a slender club. The grayish-hyaline wings are rather long and narrow; their anal angle is rather rounded off; the last segment of the fourth longitudinal vein runs upon its middle over a dis- tinct convexity of the wing and is there a little inflected ; towards its end it does not much approach the third longitudinal vein, which is here very gently curved backwards ; the sixth longitudi- nal vein becomes entirely indistinct at a considerable distance from the margin of the wing. Hab. Venezuela. (Moritz.) Observation.—Although the present species differs in some re- spects from Hutarsus aulicus, still it coincides in many important characters with it, so that it cannot be located into any other genus, unless, rather prematurely, a new genus is created for it. Hutarsus aulicus approaches the forms which prevail in the genus Diaphorus more than the above described species. Gen. XXVIII. DIAPHORUS. At the time of its adoption, and long after, the genus Diaphorus was considered as one which was very distinct from the genus Ohrysotus. The characters which Meigen uses for their dis- tinction are the following: for Chrysotus, arista apical, the eyes of the male contiguous under the antenne, and the wings some- what divaricated when in repose; for Diaphorus, arista dorsal, eyes of the male contiguous on the front, and the yeast reposing upon each other when at rest. The more species of these two genera have become known and the more carefully they have been examined, the more unsatisfac- tory Meigen’s characters have been found. North America is particularly rich in species belonging here, but showing important structural deviations. Besides the species showing a different structure of the thorax, and which were formerly classed with Chrysotus, but are united now in the genus Chrysotimus, the other species of Chrysotus, agreeing in their habitus, are divided in such, the males of which have eyes contiguous under the antenn, and in such, where the eyes are separated by the sometimes broad face; the position of DIAPHORUS. 157 the arista is likewise by no means always apical; on the contrary, it is even subapical in the majority of the species. The same happens to be the case with Diaphorus, where the eyes of the males are contiguous upon the front in some of the species only, while in others they are separated by the broad front; the arista likewise is not always distinctly dorsal, but in many species subapical, and in some truly apical. Thus none of the distinctive marks, which Meigen had established for these two genera, holds good, except for Chrysotus, the wings divaricated in repose, and the parallel wings for Diaphorus. As this charac- ter can only be observed on living specimens, it is, even if proved to be correct, entirely insufficient for a systematical distinction of both genera. In order to escape this difficulty there are two different ways to be followed: either the species, with the eyes of the males not separated upon the front, must remain with Diaphorus, and those the eyes of which, in the male, are contiguous below the antenne, must go with Chrysotus, and a new genus must be established for the species of Diaphorus and Chrysotus, the males of which have the eyes distant above as well as below the antenne. The other way to follow would be to discover characters for the distinction of Chrysotus and Diaphorus better than those which Meigen had chosen. The first of these two alternatives is liable to serious objections. The establishment of three genera would disconnect the relation naturally existing between the insects forming them, a relation based upon their general habitus, and their distinction would con- sist in a character pertaining merely to the male. Therefore nothing remains but to try the other way. If we compare first the species of Chrysotus, in which the eyes of the males are contiguous under the antenne, with those of Dia- phorus, where’ the eyes are not separated on the front, we will observe the following distinctions: The structure of the body of the species of Diaphorus is more slender, the abdomen especially is comparatively narrower, and more elongated; the hypopy- gium of the male has on the hind side four bristles of rather striking size; the feet are longer, the pulvilli of the fore tarsi in the male are not only enlarged, but considerably elongated (with the exception ‘of D. nigricans Meig.); the wings of Diapho- 158 DIPTERA OF NORTH AMERICA. [PART II. rus are comparatively larger, and have a different outline, because the anal angle is more protruding. If, separating the typical species of Diaphorus from the typical species of Chrysotus, we follow out these characters through a series of those species, which, notwithstanding the separation of their eyes upon the front, are placed into the genus Diaphorus, on account of their general habitus which approaches the typical species of Diaphorus, we find that those among the above men- tioned marks of distinction, which are peculiar only to the males, hold also good among these species; at least I do not know of any species which, being placed on account of its general habitus among the species of Diaphorus, had not on the pos- terior end of the hypopygium bristles of greater length and remarkable strength, or in which the pulvilli of the fore tarsi of the male were not elongated. It is different, however, with those marks of distinction which belong to both sexes, as also with the more slender form of the body, the greater length of the feet, and the more projecting anal angle of the wings of the species of Diaphorus; each of these charac- ters gradually fades away from species to species so that, taken singly, these characters are utterly insufficient to decide whether a species belongs to Diaphorus or to Chrysotus. As it happens, however, that where one character decreases, another one becomes more salient, it follows that in their totality they are sufficient to distinguish the females of both genera, with the exception, perhaps, of a few isolated cases. In doubtful cases it will be well to compare the description of the species of both genera. The character of the genus Dzaphorus may, therefore, be estab- lished, as follows: Form of the body rather elongated. Hyes of the male never contiguous on the face, in some species sepa- rated upon the front, in others not. Antenne short, the first joint bare, the second transverse, the third short, distinctly hairy, with a dorsal or subapical, rarely with an apical arista. Wings rather large, with strongly projecting anal angle, and thus usually somewhat broader towards the basis; the posterior transverse vein is either a little beyond, or in, or before the middle of the wing, never close to the margin of the wing; the last segment of the fourth longitudinal vein is almost straight, or but gently inflected, seldom interrupted, so that its end is thus more approxi- mated to the third longitudinal vein, without, however, converging DIAPHORUS, 159 towards it. Feet rather long, but not very slender; the first. joint of the hind tarsi without bristles; the pulvilli of the fore tarsi elongated in the males of all species; in the males of some species the same is the case with the pulvilli of the middle tarsi; in some with the pulvilli of all the tarsi. The hypopygium small, imbed- ded, on the posterior end with stouter bristles. The name of the genus (from diapopos, different) signifies nothing more but that the species on which this genus was established were remarkably different from the species of previous genera, and is therefore not at all characteristic. The known species of Diaphorus are found in Europe, Asia, Africa and America. Table for the determination of the Species. Color of the body non-metallic, black. 1 opacus Zw. : { Color of the body metallic-green. 2) Feet entirely yellow. ! 2mundus L/w. 24 Feet not entirely yellow. 3 Tegule with black cilia. 4 { Tegule with whitish cilia. 6 ( Eyes of the male contiguous. 3 spectabilis Lw. ( Eyes of the male not contiguous. 5 ( All the tibie yellow. 4 sodalis Zw. 5 | Only the first half of the four anterior tibie yellow. 5 lamellatus, nov. sp. ( Last segment of the fourth longitudinal vein not interrupted. 6 leucostomus Lw. oF Last segment of the fourth longitudinal vein interrupted. | { 7 interruptus Zw. Systematical arrangement of the Species. I. The eyes of the male contiguous upon the front. 1. opacus Lw. 3. spectabilis Lw. 2. mundus Lw. II. The eyes of the male not contiguous upon the front. A. The last segment of the fourth longitudinal vein not interrupted. 4.sodalis lw. - 6. lamellatus, nov. sp. 5. leucostomus Lw. B. The last segment of the fourth longitudinal vein interrupted. 7. interruptus Lw. 160 DIPTERA OF NORTH AMERICA. [PART EL. Description of the Species. I. THE EYES OF THE MALE CONTIGUOUS UPON THE FRONT. i. D. opacus Lorw. %.—Totus niger, tibiis piceis. Entirely black, tibie pitch-brown. Long. corp. 0.12. Long. al. 0.12— 0.13. Syn. Diaphorus opacus Lozw, Neue Beitr. VIII, 56, 1. Male. Entirely black. Face with the palpi and the proboscis black, entirely glabrous. Antenne black; third joint small ; posi- tion of the arista more subapical than dorsal. The eyes are com- pletely contiguous on the upper part of the front; immediately above the antenne a brownish-black, opaque, triangular spot lies between them. Upper side of the thorax and of the scutellum covered with brown dust and opaque. The dust upon the black pleure is more gray-brown and less distinct. The abdomen shining black, covered with black hair; the stronger bristles on the posterior part of the hypopygium very striking; its exterior appendages very small, black; coxee and femora black and with black hair; fore and middle femora on the under side with a row of sparse, erect, not very long black hairs; on the under side of the hind femora there are similar black little hairs, which are less erect and somewhat longer only towards the end. Fore and mid- dle tibiee more yellowish-brown; hind tibie dark-brown. Fore tarsi slender, the first joint as long as the following three together ; a great part of the first joint is yellowish-brown, its tip with the rest of the joints black-brown; pulvilli not very much enlarged and only moderately elongated. Middle tarsi black-brown with yellowish-brown basis ; hind tarsi entirely black-brown. Halteres and tegule black ; the cilia of the latter also black. Wings smoky- blackish, towards the anterior margin darker; they become vVisi- bly broader towards the basis ; posterior transverse vein but little before the middle of the wing; the first longitudinal vein reaches almost as far as the middle of the anterior margin and is some- what distant from the latter. Hab. New York. (Osten-Sacken.) Observation 1.—D. opacus is very closely allied to the Huro- pean D. nigricans. As I have only one specimen of the former, Iam unable to prove the coincidence of both species in all the DIAPHORUS. 161 plastic characters as fully as it is necessary when an American species is to be recognized as identical with a European species. Neither can I mention any reliable characters for the distinction of both species. I believe that the examination of a larger num- ber of specimens will establish their identity. Observation 2.—I believe I know the female of D. opacus, am however not certain, on account of the smaller length of the first longitudinal vein and the paler coloring of the hind tibize. The proboscis of this female is remarkably stout and protruding with a flattened tip; palpi rather large and broad. Face with an almost imperceptible grayish dust, with a distinct transverse swell- ing upon its middle; front with gray-brown dust and with a trans- verse furrow below its middle; all the tibie yellowish-brown, wings tinged with a dusky blackish color, though not so much as in the above-described male, and towards the fore margin not much darker; the first longitudinal vein reaches about as far as the middle between the extreme root of the wings and the end of the second longitudinal vein. All the rest as in the male. Hab. Pennsylvania. 2. D. mundus Lozrw. % and 9.—Laete viridis, pedibus totis flavis. Light metallic green, all the feet yellow. Long. corp. 0.12—0.13. Long. al. 0.12—0.13. Syn. Diaphorus mundus Loew, Neue Beitr. VIII, 57, 2. Light metallic green. The face has a blue-green, but little shining, ground color, which is rather concealed by the distinct white dust; it is somewhat broader in the female and has a dis- tinct transverse swelling. Palpi yellowish-brown, much larger in the female and blackened to a considerable extent towards the basis. Proboscis dusky yellow or yellowish-brown. Antenne brownish-yellow ; the small third joint more infuscated ; the arista almost apical; the eyes of the male meet completely on the upper part of the front, while they are separated directly above the antenne by a triangular spot of white dust. The front of the’ female is of entirely uniform breadth, only very little exceeding the breadth of the face, has a blue-green, scarcely a somewhat shining ground color, and is covered with yellowish dust. The cilia of the upper orbit are black and, on account of their brevity, a! 162 DIPTERA OF NORTH AMERICA. [PART II. but difficult to perceive; the cilia of the lateral and inferior orbits are whitish. Upper side of the thorax and of the scutellum pale- green, with metallic lustre, covered with rather thick ochre-yellow dust. Abdomen somewhat darker metallic green, often more gold- green, or coppery-brownish. The bristles at the end of the hypo- pygium are not very long; its exterior appendages brownish and very small. Coxe and feet yellow; the first two-thirds of the middle coxee blackened, the hind coxe near the basis infuscated. The hair on the feet appears black; when seen by a reflected light it changes on the tibie to brownish and on the larger portion of the femora to fallow-yellowish; the root, a part of the under side of the femora, also the fore coxe are distinctly fallow-yellow- ish. The tarsi are scarcely a little infuscated towards their tips, though their last joint is of a dark brown color. In the male the pulvilli of the fore and middle tarsi are considerably enlarged and elongated; the pulvilli of the hind tarsi are much less so. Halteres and tegule yellowish with black-brown cilia, which in some directions have a yellowish lustre. Wings grayish-hyaline, on the anterior half usually somewhat yellowish with yellowish- brown veins; they are rather large and towards the basis a little broader, but their greater breadth is not so near to the posterior margin as in the previous species; the posterior transverse vein is not nearer to the extreme tip of the wing than it is to its root and the first longitudinal vein reaches scarcely above the first third of the length of the whole wing. Hab. Pennsylvania. 3. D. spectabilis Lorw. ‘%.—Aeneo-viridis, femoribus nigris, tibiis tarsorumque omnium basi flavis, ciliis tegularum nigris, oculis maris in fronte contiguis. Bronze green, femora black, tibie and the root of all the tarsi yellow, cilia of the tegule black, the eyes of the male contiguous on the front. Long. corp. 0.183—0.17. Long. al. 0.15—0.16. Syn. Diaphorus spectabilis Lozw, Neue Beitr. VIII, 57, 3. Dark metallic-green, thorax and abdomen more bronze-green, the former sometimes more coppery. Face blue-green with thick white dust, which conceals considerably the ground color. Palpi and proboscis black. Antenne black, small; arista almost com- | pletely apical. The eyes meeting upon the front to a large extent and separated only by a very small triangular spot, immediately DIAPHORUS. 163 above the antenne. Cilia on the upper orbit black, on the lower and lateral orbits white. Upper side of the thorax and scutellum covered with yellow-brownish dust. The stouter bristles on the posterior end of the very small hypopygium rather striking; its exterior appendages brown and very small. Coxe black and with whitish dust; the hair on the fore cox appears in most directions black, in others fallow-brownish. Femora black, somewhat with a green reflection; the tip of the fore and middie femora brownish- yellow; their black hair, even on the under side, neither of con- siderable length nor density. Tibiz brownish-yellow, rather slender, with a few bristles. Fore tarsi very slender, from the tip of the first joint black-brown, though the basis of the second joint is again paler than the tip of the first; their first joint is as long as the other four together; the pulvilli are very much enlarged and elongated. Middle. tarsi of an entirely similar structure, of the same color, but their pulvilli are somewhat less enlarged ; hind tarsi from the tip of the first joint black-brown, their pulvilli but very little enlarged; the yellowish tegule with blackish cilia, which assume a yellowish glitter in a reflected light. Halteres yellowish, the tip of their knob usually somewhat infuscated. Wings tinged with gray, with blackish-brown veins, along which, in faded specimens, there are blackish-brown margins; they are broad, though their greatest breadth is not very close to the pos- terior angle; the space between the third and fourth longitudinal veins is rather wide; the last segment of the latter shows a very gentle flexure; posterior transverse vein rather long and somewhat beyond the middle of the wing; the first longitudinal vein reaches somewhat beyond the first third of the whole length of the wings and is not very far distant from the anterior margin. Hab. District Columbia. (Osten-Sacken.) II. THE EYES OF THE MALE NOT CONTIGUOUS UPON THE FRONT. A. The last segment of the fourth longitudinal vein not interrupted. 4. D. sodalis Lorw. % and 9.—Aeneo-viridis, femoribus nigris, tibiis omnibus tarsorumque anteriorum basi flavis, tarsis posticis totis ex nigro fuscis, ciliis tegularum nigris, oculis maris in fronte separatis. Bronze-green ; femora black; all the tibie and the basis of the four ante- rior tarsi yellow; all the hind tarsi black-browns cilia of the tegule 164 DIPTERA OF NORTH AMERICA. [PART II. black; eyes of the male separated upon the front. Long. corp. 0.14— 0.15. Long. al. 0.15. : Syn. Diaphorus sodalis Lozrw, Neue Beitr. VIII, 58,4. Rather dark metallic-green, the abdomen and sometimes also the thorax more bronze-green, the scuéellum in one specimen violet upon its middle. Face of the male of uniform breadth, green-blue with thick white dust; the face. of the female visibly broader, more green, with less dust, below the middle with a transverse swelling. Palpi of the male whitish, only near the extreme basis somewhat blackish; the palpi of the female much larger, only at the tip dusky-whitish, otherwise blackish. Antennee small, black, with an apical arista. Front of the male of uniform breadth, somewhat exceeding the breadth of the face, blue with yellow- brownish dust, and green and shining upon the vertex. The front of the female is considerably broader, more green and less thickly dusted, the dust has in the vicinity of the antenne a whitish appearance. Cilia of the upper orbit black, those of the lateral and inferior orbits whitish. Thorax distinctly, but not very thickly, dusted. The coarser bristles on the posterior end of the small hypopygium are less striking; the very small exterior appendages are brownish-black. Coxe black with whitish dust; the fore coxze indistinctly dingy white-yellowish at the tip; the sparse hair on the front side pale, but the bristles of the tip, black. The tro- chanter of the fore and middle feet dusky-yellowish, of the hind feet more brownish. -Femora black with green lustre; their black hair is comparatively short; only on the under side of the femora of the male, very closely to the tip, a few somewhat longer bristle- like hairs. The tips of the four anterior femora and the tibie are brownish-yellow, but the tip of the hind tibie is rather dark- brown. The fore tarsi of the male are slender and elongated, brownish-yellow at the root, then gradually becoming more infus- cated ; their first joint is about as long as the two following taken together; the pulvilli are but moderately enlarged and elongated. The middle tarsi of the male are of the same color as the fore tarsi and of the same structure, but the first joint is almost as long as the following four taken together, and the pulvilli are not so much enlarged and less elongated. The fore and middle tarsi of the female correspond in color with those of the male, are, how- ever, considerably shorter, have no enlarged pulvilli, and the first DIAPHORUS. 165 joint of the fore tarsi is about equal in length to all the other joints together. The short hind tarsi are in both sexes dark black-brown. Cilia of the white-yellowish tegule black. Halteres white-yellow- ish. Wings tinged with gray, with black-brown veins, which are margined with dusky in faded specimens; they are rather large and broad ; their greatest breadth is close before the middle; the posterior transverse vein lies in the middle between the extreme root and the extreme tip of the wing; the fourth longitudinal vein is somewhat distant from the third one; the first longitudinal vein is comparatively close to the margin of the wing and scarcely reaches one-third of the length of the wings. Hab. New York. . 5. D. lamellatus, nov. sp. %.— Aeneo-viridis, pedibus nigris, tibiarum anteriorum dimidio basali flavo, ciliis tegularum nigris, oculis maris in fronte separatis. Bronze-green ; feet black; basal half of the four anterior tibie yellow; cilia of the tegule black; the eyes of the male separated upon the front. —Long. corp. 0.13. Long. al. 0.14. Dark metallic-green, the color of the scutellum sometimes more blue and that of the abdomen more coppery. Face with thick ' whitish dust. Palpi small, whitish and fringed with a few black hairs. Antenne small, black; the arista subapical. Eyes separated ; front much narrower than the face, broader below than above, and covered with thick white dust. Cilia of the upper orbit black, of the lateral and inferior orbits whitish. Thorax, though with dis- tinct, but very thin brownish-yellow dust. On the posterior end of the hypopygium there are six bristles of remarkable strength. The brownish-black exterior appendages are of much larger size than in the kindred species ; they are elongated spatule-shaped, very narrow at the root, rounded at the tip and fringed with blackish hairs. Coxe and feet black; the trochanter of the fore cox, the extreme tip of the four anterior femora and basal half of the four anterior tibize yellow. The hair upon the feet is black, on the under side of the hind femora elongated and more dense towards their tip. The pulvilli of the fore tarsi are rather un- commonly elongated, while those of the middle tarsi exhibit only a small elongation and those of the hind tarsi none at all. Cilia of the white-yellowish tegule black. Halteres white-yellowish. Wings gray with brownish-black veins, rather large and broad ; 166 DIPTERA OF NORTH AMERICA. [PART II. they have their greatest breadth somewhat before their middle; the posterior transverse vein is in the middle between the extreme root and the tip of the wings; the first longitudinal vein runs at least as far as the third of the length of the wing. . Hab. Middle States. (Osten-Sacken.:) 6. D. leucestomus Lozrw. % and 9.—Laete viridis, thorace et scutello interdum cerulescentibus, tegularum ciliis albidis, vend longi- tudinali quarta non interrupta. Light green, thorax and scutellum sometimes more blue; cilia of the tegule whitish, the fourth longitudinal vein not interrupted. Long. corp. 0.09—0.10. Long. al. 0.12. Syn. Diaphorus leucostomus Loew, Neue Beitr. VIII, 58, 5. Male. Light green, metallic, shining, thorax and scutellum sometimes sky-blue. Face for a male very broad, deepened length- wise, without transverse swelling, so thickly covered with snow- white dust, that the ground-color becomes invisible. Palpi protruding, much larger than in the males of other species; proboscis very small, black. Antennee black, larger than in other species ; the third joint is particularly distinguished by its more considerable size and is extended at the end into a short point; arista inserted on the upper side before the tip of this point, but so much bent downward as to be easily mistaken for being apical. Front of uniform breadth, scarcely exceeding that of the face, blue with white dust, which is thicker near the antenne and is almost totally wanting upon the vertex. Cilia of the upper orbit black, those of the lower and lateral orbits whitish. Thorax with thin gray-whitish dust. The bristles on the posterior margin of the small hypopygium rather long and strong; its outer appen- dages are not distinctly visible. Coxe black, the foremost dusky- whitish at the tip, on the front side rather bright blue-green and fringed with whitish hair, but without black hairs or bristles. Femora metallie blue-green with yellowish tip, with very short hair. Tibise and tarsi yellowish, the latter towards the end gradu- ally somewhat darker, but only their last joint brown; fore tibie without strong bristles, middle and hind tibie with a stronger bristle on the exterior edge of their upper side and not far from the root; the hind tibia, on the exterior edge of the upper side, are sparsely beset with shorter and weaker bristles. Fore tarsi ? * DIAPHORUS. 167 long and slender; their first joint about as long as the other three together, the pulvilli considerably enlarged and elongated. Middle tarsi like the fore tarsi and of a similar color, but their first joint about as long as the other four together, and the pulvilli not quite so large and not quite so elongated as on the fore tarsi. Hind tarsi more infuscated, only the root of the first joint brown- ish-yellow. Tegule whitish with whitish cilia. Halteres also whitish. Wings hyaline, but very little tinged with gray; veins brown-black ; the posterior transverse vein rather exactly in the middle between the root and the tip of the wing; the first longi- tudinal vein reaches but very little beyond the third part of the length of the wings. Female. Face very little broader than in the male, with thick white powder, although appearing gray on account of the appa- rent dark ground-color; it is somewhat deepened upon its larger upper part and gently convex upon its smaller lower part; both parts are divided by an imperfect transverse swelling. Palpi whitish, near the basis somewhat gray. Antenne considerably smaller than in the male, the third joint much smaller, rounded, with an almost imperceptible angle below the insertion of the arista. Front more broad and more green than in the male. Tarsi shorter and usually somewhat more infuscated than those of the male. The pulvilli not enlarged. Hab. Maryland. (Osten-Sacken.) Observation 1.—I believe that I am not mistaken with regard to their belonging together, but I rather preferred to describe them separately. If, contrary to expectation, they should prove as not belonging together, then the name must remain to the male, which I consider as typical. Observation 2.—D. leucostomus approaches in its entire habitus several species which I believe must be referred to Chrysotus more than any other species of the genus Diaphorus, known tome. The elongation into a point of the third joint of the antenne in the male seems to indicate a relationship to Synarthrus barbatus ; neverthe- Jess the latter differs materially by its narrow, not deepened face, by the conspicuously elongated third joint of the antenne and also by the entirely apical insertion of the arista. 168 DIPTERA OF NORTH AMERICA. [PART IL. B. The last segment of the fourth longitudinal vein interrupted. % D. interruptus Lozrw. %.—Obscure virescens, modice nitens, femoribus et tibiis concoloribus, genibus testaceis, tarsis fuscis, vena alarum longitudinali quarta interrupta. Dark green, moderately shining; femora and tibie also green; knees brownish-yellow ; tarsi brown; the fourth longitudinal vein interrupted. —Long. corp. 0.23. Long. al. 0.20. Syn. Diaphorus interruptus Lo—Ew, Wien. Ent. Monatschr. V, 37, 9.—Lozrw, Neue Beitr. VII, 59, 6. _ Male. Rather dark green, not very shining. Face of uniform breadth with the front, very broad for a male, covered with thick whitish dust, so that the ground color becomes invisible, moder- ately deepened and without a transverse swelling. Palpi and proboscis black. Antenne black; their first joint somewhat longer than in other species; the third joint rounded; position of the arista distinctly dorsal. Front with thick dusky-whitish powder, so as to conceal the ground color. Cilia of the upper orbit black ; the cilia of the lateral and inferior orbits are whitish and form a considerable fringe. Upper side of the thorax and of the scutel- lum dark-green and dull from grayish dust. Abdomen more shining-green, with extensive but less thick whitish dust and on the anterior part of the segments coppery to a large extent. The four stout bristles on the posterior end of the small and imbedded hypopygium are very prominent. Coxe black; the fore and middle coxee on the front side more black-green and fringed with black bristles. Femora metallic green, stout, beset with dense and coarse black hair, on the under side with numerous, but not strong black bristles. Knees yellowish-brown. Tibiz on the under and front side black-brown, on the upper and hind side dark metallic-green, of strong structure and with unusually strong bristles. Tarsi black-brown, the root of the anterior ones and the under side of all the others more brownish-red; all tarsi are stouter and less elongated than in the other species known to me, also with more hair; the pulvilli are all very much enlarged and elongated. 'Tegule yellowish with pale-yellowish cilia. Wings hyaline, scarcely a little tinged with gray, alternately with yellow and brown veins; first longitudinal vein somewhat distant from the margin of the wing and reaching about as far as the middle of the wing; the third longitudinal vein is very close to the second LYRONEURUS. 1¢69 and ends long before the tip of the wing, although its end is very much curved backwards; the posterior transverse vein is very short and lies much before the middle of the wing, so that the last segment of the fourth longitudinal vein becomes uncommonly long ; the latter diverges very much from the third longitudinal vein, is entirely interrupted upon its second third and the last third, which is remarkable by its slenderness, is pushed forward towards the third longitudinal vein. Hab. Cuba. (Poey.) Observation.—The interruption of the last segment of the fourth longitudinal vein is particularly striking in this species; a trace of it is also found in some of the European species. The position and the course of the third longitudinal vein recall the neuration of Lyroneurus. Gen. XXIX. LWRONEURUS. The following are the characters of the genus Lyroneurus: The body is elongated. Eyes upon front and face widely sepa- rated in both sexes. Antenne short; the first joint not hairy, the second transverse, the third short, rounded, distinctly pubescent ; arista apical. Wings very large, at the tip broad and very ob- tuse ; the posterior transverse vein does not approach the margin of the wing; the third longitudinal vein very close to the serond and very much turned backward at the end; the space between the third and fourth longitudinal veins remarkably broad; last segment of the fourth longitudinal vein distinctly inflected. Feet rather long, but not very slender; first joint of the hind tarsi without bristles. Pulvilli of the fore tarsi in the male not elon- gated. Hypopygium small, imbedded, at the posterior end with four strong bristles ; its appendages are very small and hidden. The genus Lyroneurus is by far the next related to the genus Diaphorus. A more minute examination of the American spe- cies of Diaphorus has satisfied me that this relationship is greater than I supposed, when establishing the genus Lyro- neurus (Wien. Ent. Monatsch. I, 37). The larger size of the wings, which are very broad at the tip, the greater breadth of the space between the third and fourth longitudinal veins, the distinct flexure of the last segment of the fourth longitudinal vein and the not elongated pulvilli of the fore tarsi in the male, these are the 170 DIPTERA OF NORTH AMERICA. [PART II. characters which distinguish Lyroneurus from Diaphorus. The last of these characters is decisive for the maintenance of the genus Lyroneurus, as the elongation of the pulvilli of the fore tarsi in the male cannot be dispensed with in the character of the genus Diaphorus, without rendering the limit between Diaphorus and Chrysotus entirely uncertain. The genus Lyroneurus, to which also belongs D. adustus Wied., seems to contain only American species; they appear to be particularly numerous in South America. The name of the genus (from avpa, the lyre, and vetpor, the nerve) has reference to the lyre-shaped space between the third and fourth longitudinal veins. i. L. coerullescems Lorw. 4.—Viridis, thorace et abdominis dorso ceruleis, femorum apice tibiisque totis testaceis, tarsis ex nigro fuscis. Green, thorax and dorsum of the abdomen sky-blue; tip of the femora and the whole tibie brownish-yellow; tarsi black-brown. Long. corp. 0.22. Long. al. 0.25. Syn. Lyroneurus cxrulescens Loew, Wien. Ent. Mon. I, 39.—Lorw, Neue Beitr. VIII, 60, 1. Light metallic-green, most of the upper side of the thorax, of the scutellum and the greater part of the upper side of the abdo- men sky-blue or violet. Face of considerable and uniform breadth and so thickly covered with gray-whitish dust that no trace of the blue-green ground-color is left. Palpi black, with white-gray dust and with strong black hairs. Antenne black, short. Front of uniform breadth, equal to that of the face; the dust upon it is so thick that hardly a trace of the ground color is left. Cilia of the upper orbit black, cilia on the lateral and inferior orbits white and forming a rather thick beard. Thorax pale green, upon the middle line and upon the whole hind part sky-blue, or shifting to violet. The rather thick dust on the upper side of the thorax has a gray-brownish tinge. Scutellum blue or violet with gray-brown dust, on each side with a stronger and with a weaker bristle, on the surface bare. Pleure green with rather thick gray-white dust. Abdomen. cylindrical, metallic-green; its upper side shining blue or violet from the middle of the second segment to the tip. The hair upon the abdomen is black ; the bristles on the hind margin of the single segments are but of moderate length. CHRYSOTUS. Eti The lateral margin of the abdomen shows a distinct gray-whitish dust. The small hypopygium is completely imbedded ; it has (as I now perceive on a well-preserved specimen) four strong bristles on the hind margin, like the hypopygium of the males of Diapho- rus; the appendages of the hypopygium are extremely small, and completely hidden. Coxe black, somewhat shifting to green, ren- dered gray by a covering of dust; the fore coxe at the tip are of a dusky-yellowish color, and beset with black bristles, while on their front side there is some pale hair. Femora green, not strong and fringed with comparatively short black hair. On the four anterior femora the tip to a considerable extent, and on the hind femora only the extreme tip are of a brownish-yellow color. Tibiz brownish-yellow, the tip of the hind tibiz strongly infus- cated, all the tibise with but few bristles. Tarsi black-brown, the first joint of the middle tarsi up to its first third, that of the fore tarsi up to the middle, yellow-brownish. Fore tarsi but little longer than the fore tibiz, and their first joint not quite so long as the rest; their pulvilli not enlarged. Tegule white-yellowish with brownish-black cilia. Wings grayish hyaline with a greasy lustre ; veins brown; the first longitudinal vein lies close to the margin of the wing and reaches only a little over the first quarter of the length of the wings; the costa is rather stout, particularly near the end of the second longitudinal vein; the posterior trans- verse vein is straight and is pretty much in the middle between the root and the tip of the wing. Hab. Mexico. Gen. XXX. CHRYSOTUS. The genus Chrysotus contains on the average only small spe- cies. The eyes of the males in many species meet upon the front ; in males of other species they are separated. The front becomes broader towards the vertex in most of these species, and more so than is the case with the species of Diaphorus. Antenne very short ; the first joint without any hair; the second transverse ; the third rounded, often rather kidney-shaped, sometimes pointed and distinctly hairy; only in one species, which, on account of the agreement of all the other characters, I have located with Chry- sotus, the third joint of the antennz is considerably longer, almost of the same shape as in most of the species of Argyra. The two- 172 DIPTERA OF NORTH AMERICA. [PART 1. jointed arista has an apical or a subapical position. Hypopygium imbedded, distinctly hairy ; its outer appendages have a lamelli- form structure and are usually concealed. Feet rather short and comparatively strong. The first joint of the hind tarsi without bristles. Wings in comparison rather broad and very rounded at the tip ; the small transverse vein in most of the species very far distant from the margin of the wing; the last segment of the fourth longitudinal vein straight, parallel or almost parallel to the third longitudinal vein. I have already expressed myself in detail (see Diaphorus) about the difficulty attending the distinction of the genera Dia- phorus and Chrysotus. I have pointed out that I consider the smaller size, the less slender form, the comparatively smaller size of the wings, the smaller length of the feet, the not elongated pul- villi of the fore tarsi in the male and the absence of stronger bris- tles on the posterior end of the hypopygium, as those characters, which enable us to distinguish the species of Chrysotus from Diaphorus. The range of the genus Chrysotus is known to be Europe, Asia, Africa, and America. The name of the genus (from ypvowzos, gilded) has reference to the gold-green color of many species. - Mr. Say has described three North American species of Chry- sotus ; hardly one of the three probably belongs to this genus, as Mr. Say seems to have misunderstood its characters; Chrysotus nubtlus may be a Medeterus, C. concinnarius is perhaps a Dia- phorus, and C. abdominals is probably a Chrysotimus. In the next place Mr. Macquart has described a female as Chrysotus viridifemora ; if face and front are covered with white dust, as it seems to follow from his description, this character and the color of the feet may perhaps help to recognize the species. Finally, Mr. Walker has, in his usual careless manner, published a Chry- sotus incertus, which probably will remain incertus forever; as he has not even stated the sex of the specimen described, his descrip+ tion is of no use whatever. I know, thus far, twelve North American species of Chrysotus, of which five are represented in both sexes, three only in the male, and four in the female sex; two of the latter offer but so little peculiar characteristics, that I hesitate with their publication, while the two others are striking enough to preclude the possi- bility of a mistake. CHRYSOTUS. I Wo Table for the determination of the Species. 1 | Third joint of the antenne elongated. 1 cornutus, nov. sp. Third joint of the antenne not elongated at all. 2 { Femora of dark color. 3 Femora of pale color. rae: 3 f Ground-color of the palpi pale. a Ground-color of the palpi blackish. 5 4 { Palpi white. 2 longimanus Lw. Palpi yellow, near the basis blackish. 3 validus Lw. | Cilia of the tegule black. 6 Cilia of the tegule pale. 8 Nag of the male separated. 6 vividus, nov. sp. Eyes of the male contiguous. 7 ( Four anterior tibiz of the male and all the tibie of the female yellow. u 4 obliquus Lw. - Both the fore tibize of the male and the four anterior tibie of the L female yellow. 5 affinis Zw. g | Wings of the male with thickened costa. 9 Wings of the male without a thickened costa. 10 9 | Costa of the male very much incrassated. 7 costalis Lw. Costa of the male moderately incrassated. 8 subcostatus, nov. sp. (Smaller species, with about three bristles on the upper side of the | hind tibiz. , 9 discolor Lw. eH Larger species, with about five bristles on the upper side of the hind tibie. 10 auratus Lw. ll { Antenne entirely black. 11 pallipes Lw. First joint of the antenne red. 12 picticornis, nov. sp. Systematical arrangement of the Species. I. Third joint of the antenne elongated. 1. cornutus, nov. sp. II. Third joint of the antennz not elongated at all. A. Femora of a dark color. A. Ground®color of the palpi pale. 2. longimanus Lw. 3. validus Zw. s. Ground-color of the palpi blackish. 1. Cilia of the tegule black. 4. obliquus lw. 6. vividus, nov. sp. 5. affinis Lw. 2. Cilia of the tegule pale. 174 DIPTERA OF NORTH AMERICA. [PART IL. a. Costa of the male incrassated. 7. costalis Lw. 8. subcostatus, nov. sp. b. Costa of the male not incrassated. 9. discolor Lw. 10. auratus Zw. B. Femora of a pale color. 11. pallipes Lw. 12. picticornis, nov. sp. Description of the Species. I. THIRD JOINT OF THE ANTENN® ELONGATED. i. C. cornutus, nov. sp. %.—Obscure viridis, paulo nitens, tertio antennarum articulo elongato, oculis infra antennas contiguis, tegularum ciliis femoribusque nigris, tibiis testaceis, tarsis anterioribus inde ab articuli primi apice posticisque totis fuscis. Dark green, little shining; the last joint of the antenne elongated, eyes meeting below the antenne; cilia of the tegule and femora black; tibie brownish-yellow; the four anterior tarsi from the tip of the first joint and all the hind tarsi brown. Long. corp. 0.09. Long. al. 0.09. Dark green, moderately shining. Antenne black, the third joint untommonly elongated for a Chrysotus, almost of the same shape as in the species of Argyra, only somewhat longer, with a blunt tip; arista. apical. Front black-green. Coxe and femora black, the latter with brownish-yellow tip. Tibi brownish-yel- low, the hindmost black-brown at the tip and fringed on their upper side with a moderate number of bristles. The four anterior tarsi are black-brown from the tip of the first joint ; the hind tarsi are of a black-brown color. Cilia of the tegule black. Wings of the usual structure peculiar to the genus Chrysotus, hyaline with a gray tinge; the small transverse vein is before the middle of the wing and is short. Hab. Illinois. (Le Baron.) Observation.—This species is distinguished from all other spe- cies of the genus Chrysotus in a striking manner by the unusual elongation of the third joint of the antenne, agrees, however, com- pletely in all other respects. I have hesitated to establish a new genus upon it, as but a single character constitutes its difference from Chrysotus, which character belongs probably only to the male. — -T or CHRYSOTUS. «» II. THE THIRD JOINT OF THE ANTENNZ NOT ELONGATED AT ALL. A. Femora of a dark color. A. Ground color of the palpi pale. 2. C.longimanus Lorw. %.—Viridis, nitens, palpis albis, tarsis anterioribus tenuibus et longis. Green, shining, palpi white, the four anterior tarsi long and slender. Long. corp. 0.14. Long. al. 0.14. Syn. Chrysotus longimanus Lorw, Neue Beitr. VIII, 62, 1. Shining green. Face of uniform, and for a male, rather consi- derable breadth ; the covering of white dust does not entirely con- ceal the green-blue ground color. Palpi white, not very broad, but for a male rather long. The third joint of the antenne not large, rather kidney-shaped ; the position of the arista rather pre- cisely apical. Front metallic-green, very little dusty and towards the vertex very little enlarged. Upper side of the thorax covered only with a thin brownish-yellow dust. Coxe and femora black with a blue-green metallic lustre, which is more distinct on the femora; the tip of the fore coxe yellow, the tip of the posterior coxee dusky-brown. On the anterior feet the tip of the femora, the tibiz and the greatest part of the first joint of the tarsi are yellow ; the remainder of the unusually slender and long fore tarsi is dark brown ; the hind tibize are yellow, but distinctly infuscated at the tip; the hind tarsi are dark brown. The hair upon the feet is short and the bristles very scarce. Cilia of the tegulx pale. Wings distinctly tinged with gray and with rather black veins. The posterior transverse vein is more distant from the root of the wing than in most of the other species. Hab. Middle States. 3. C. validus Lorw. 9.—Aureo-viridis, nitens, palpis flavis, basim versus nigricantibus, pedibus flavis, femoribus posticis excepto apice nigris, viridi-micantibus, femoribus anticis nigro lituratis. Golden-green, shining, palpi yellow, towards the basis blackish; feet yel- low, hind femora with the exception of the tip black, with greénish lus- tre, the anterior femora striped with black. Long. corp. 0.13. Long. al. 0.13. Syn. Chrysotus validus Loew, Neue Beitr. VIII, 63, 2. Golden-green, shining. Face for a female of moderate breadth ; 176 DIPTERA OF NORTH AMERICA. [PART II. its covering with whitish dust does not entirely conceal the blue- green ground-color ; the usual transverse swelling lies, as in most of the other species, usually rather far below its middle; palpi for a female of moderate size, yellowish and blackish at the root. The third joint of the antennze comparatively not large, rather rounded. Front metallic-green, with thin dust and towards the vertex a lit- tle enlarged. Upper side of the thorax only with thin, brownish- yellow dust. Coxe and hind femora black with metallic-green lustre, which is most distinctly seen on the latter. The tip of the fore coxe yellow; fore feet yellow ; femora on the upper side with a black longitudinal stripe, the tarsi infuscated from the tip of the first joint; middle feet entirely yellow; the tarsi infuscated only from the tip of the frst joint ; on the hind feet the extreme tip of the femora, the tibize and the greater part of the first joint of the tarsi are of a pale color. The hair upon the feet is short and rather delicate, the bristles only few, though the little bristles on the hind tibie are rather long. The pale hairs on the cilia of the tegule seem to have, in some directions, a dark appearance. Wings only slightly tinged with gray, with dark brown veins. The posterior transverse vein approaches but little the roct of the wing, and is somewhat farther from it than in most of the other species. ; Hab. Middle States. (Osten-Sacken. ) B. Ground color of the palpi blackish. 1. Cilia of the tegule black. 4. C. obliquus Lorw. % and 9.—Viridis, nitens, tegularum ciliis nigris, femoribus nigris viridi-micantibus, summo anteriorum apice flavo. *,. Oculis contiguis, tertio antennarum articulo obliquo, tibiis anteriori- bus flavis. ; ©. Tibiis omnibus flavis. Shining-green ; cilia of the tegule black ; femora black, with green lustre ; the extreme tip of the four anterior femora yellow. *,. The eyes contiguous; the third joint of the antenne oblique ; the four anterior tibie yellow. Q. All the tibie yellow. Long. corp. 0.09—0.10. Long. al. 0.09—0.10. Syn. Chrysotus obliquus Lozw, Neue Beitr. VIII, 63, 3. Male. Eyes completely contiguous upon the face; the small triangular spot between them, immediately below the antennae, is CHRYSOTUS. . 1i7 covered with brown-gray dust; the very small palpi black. The third joint of the antenne comparatively with long hair, rather large, oblique, its upper margin much more arched than the lower margin, which is almost straight; the arista is subapical. Front _ metallic-green, without a distinct trace of dust, and becoming of broader upwards. Thorax shining green, sometimes rather gold- green. Coxe and femora black with metallic-green lustre; on the four anterior feet the extreme tip of the femora, the tibie and the greater part of the first joint of the tarsi are yellow, the fol- lowing part of the tarsi black-brown; the hind tibie and hind tarsi are decidedly of a brown-black color. The hair upon the feet, though somewhat rough, is short, and even on the hind tibix of very moderate length; the hind femora have on the under side before the tip but a few bristle-like hairs ; the bristles on the tibiz are very scarce; the pulvilli are very small even on the fore tarsi. Cilia of the tegule black, though some of them exhibit in a re- flected light a yellow-brownish glitter. Wings somewhat tinged with gray; veins black; the posterior transverse vein very close to the root of the wing; the last segment of the fourth longitu- dinal vein parallel to the third and ending a little before the tip of the wing. Female. Face of moderate breadth with grayish-white dust upon rather black ground; the usual transverse swelling is far below its middle. Palpi blackish, the third joint of the antennze smaller than that of males, and its oblique form less striking. The brownish-yellow dust on the upper side of the thorax some- what more dense than in males. The color of the four anterior feet like that of the males; the hind tibize yellow with a somewhat dusky tip ; hind tarsi dark brown, the first joint is sometimes more yellowish-brown near the basis. Wings like those of the male, only the anal angle somewhat more protruding. Hab. New York. (Osten-Sacken.) Observation.—I have no ground for doubting that these-two sexes belong together, as all those characters which distinguish the male from the female are within the range of the sexual dis-. tinctions peculiar to this genus, and the agreement of all the other characters is very striking. 12 178 DIPTERA OF NORTH AMERICA. [PART II. °5. C. affimis Lorw. 4% and 9.—Viridis, nitens, tegularum ciliis nigris, femoribus nigris viridi-micantibus, summo anteriorum apice ex flavo piceo. *%. Oculis contiguis, tertio antennarum articulo subobliquo, tibiis anticis ex flavo piceis. . Tibiis anterioribus ex flavo piceis. Shining green, cilia of the tegule black; femora black with green lustre ; the extreme tip of the four anterior femora yellow-brownish. *,. Eyes contiguous; the third joint of the antenne but little oblique; the fore tibiz yellow-brownish. ©. The four anterior tibie yellow-brownish. Long. corp. 0.09—0.10. Long. al. 0.10. Syn. Chrysotus affinis Loew, Neue Beitr. VIII, 64, 4. Male. It is so much like the male of C. obliquus, that a state- ment of the differences will be sufficient for its recognition. The third joint of the antenne is visibly smaller and less oblique; the hind femora have upon the second part of their under side a greater number of bristle-like black hairs; finally the hair upon the hind tibise is much longer; the feet are considerably darker; fore tibiee more yellowish-brown than yellow and towards their tips distinctly dusky ; middle tibie often almost brown-black, but always with a yellowish-brown basis; middle tarsi entirely black- brown; fore tarsi only near the basis of a pale brown color. I have not discovered any other differences. Female. I have only a single female, which I think belongs here. It resembles the female of the preceding species very much, only the fore tibize are more of a brownish-yellow color and dusky towards the tip; the middle tibie are still darker than the fore tibie and the hind tibie are like those of the male, black. The third joint of the antenne is somewhat smaller than in the females of C. obliquus. Hab. Middle States. (Osten-Sacken.) 6. C. vividus, nov. sp. %.—Viridis, nitens, ciliis tegularum nigris, femoribus nigris viridi-micantibus, genibus tibiisque flavis, maris oculis distantibus et costa alarum non incrassata. Green, shining, cilia of the tegule black, femora black with green lustre, knees and tibie yellow; in the male, the eyes separated and the costa not thickened. Long. corp. 0.09. Long. al. 0.09. Metallic-green, bright, but on the upper side of the thorax with a rather thick brownish-yellow dust and therefore more dull. The CHRYSOTUS. 179 eyes are separated by the face, which is comparatively broad for a male ; the face has a rather distinetly impressed middle line, is of a metallic-green color, but opaque on account of the cover of whitish dust. Palpi black, their whitish powder only becomes visible when seen in a very oblique direction. Antenne black, of middle size, their third joint is somewhat longer than in most of the other species, hairy, and of a somewhat irregular form, because that part, where the arista is inserted, is somewhat produced in the shape of alobe. Front metallic-green, dull on account of brownish-yellow dust. Coxe and femora black, the latter with a green metallic lustre; the second joint of the fore coxe, the tips of all the femora, all the tibie and all the tarsi as far as the tip of the first joint, yellow, the end of the feet brownish-black. Hairs and bristles wpon the feet very short, the bristles also very few in number. Pulvilli of the fore tarsi rather small. Cilia of the tegule black. Wings somewhat grayish, with a rather protruding anal angle; the costa shows no thickening; the last segment of the fourth longitudinal vein is scarcely a little inflected, parallel with the third and ends immediately before the extreme tip of the wing. Hab. Ulinois. (Le Baron.) Observation.—It is not necessary, when identifying this species, to pay too much attention to the shape of the third joint of the antenne, as it sometimes changes its form, especially when recently developed specimens dry up. The separated eyes, the black cilia of the tegule, the color of the feet, and the costa without a thick- ening, are characters which prevent its being confounded with any other species known to me. 2. Cilia of the tegule pale. a. Costa of the male thickened. %. C. costalis Lozrw. % and 9.—Viridis, polline confertissimo ex fusco cinereo opacus, femoribus nigris, genibus tibiisque flavis, maris oculis distantibus et media cost parte valde incrassata. Green, opaque on account of a very thick brownish-gray dust ; femora black; . knees and tibizw yellow; the eyes not contiguous in the male and the middle of the costa thickened. Long. corp. 0.09—0.10. Long. al. 0.09. Syn. Chrysotus costalis Lozw, Neue Beitr. VIII, 64, 5. Male. Ground-color metallic-green, or blue-green, but so thickly covered with brown-gray dust as to conceal this color. 180 DIPTERA OF NORTH AMERICA. [PART It. Face broad for a male, though a little narrower downward; the dust is of about the same color as the rest of the body, usually, however, somewhat paler. Palpi black, of. middle size. The third joint of the antennz small, kidney-shaped, with an entirely apical arista. Front quite opaque on account of its thick dust. The metallic-green ground-color of the upper side of the thorax becomes more visible only when seen from behind. Seutellum and abdomen less thickly covered with dust than the thorax, so that their metallic ground-color becomes more apparent in most direc- tions. ‘The hair upon the abdomen appears, in a reflected light, of a pale-brownish color. Coxe and femora black, without a dis- tinct green lustre, the second joint of the fore coxe, the extreme tip of all femora, all the tibise and all the tarsi as far as the tip of the first joint, yellow ; the end of the tarsi dark brown. ‘The hair and bristles upon the feet very short everywhere, the bristles also very scarce; the pulvilli of the fore tarsi rather small. Cilia of the tegule pale. Wings somewhat grayish, with a rather protrud- ing anal angle and of more uniform breadth than in most of the other species; the fore margin of the wings shows a strong black thickening, which commences abruptly at the end of the first lon- gitudinal vein, becomes then gradually thinner and disappears already before the end of the second longitudinal vein; the last segment of the fourth longitudinal vein is not inflected at all, parallel with the third and ends rather exactly in the extreme tip of the wing; the posterior transverse vein is almost at an equal distance from the extreme root and from the tip of the wing. Hab. Florida. Female. It resembles the male very much, only the dust upon the whole body is more thick and the green ground-color of the abdomen less bright. The face is not very broad for a female; its covering of thick dust has the same color as that on the rest of the body ; although the usual transverse swelling lies somewhat below the middle of the face, it is considerably higher than in the females of all the other species known to me, so that the face is divided by it into two almost equal parts. The wings have the same shape of equal breadth as in the male, show however no trace of a thickening on the fore margin. Hab. Maryland. (Osten-Sacken.) CHRYSOTUS. 18] Ss. C. subcostatus, nov. sp. %.—Viridis, polline raro ex fusco cine- reo aspersus, femoribus nigris, viridi-micantibus, genibus tibiisque flavis, maris oculis distantibus et media parte cost modice incrassata. Green, sparsely covered with brownish-gray dust; femora black, with green lustre; knees and tibie yellow; the eyes in the male separated, and the costa moderately thickened. Long. corp. 0.09. Long. al. 0.09. Metallic-green or blue-green, upon the thorax with not very thick brownish-gray dust and therefore less shining. Face for a male rather broad, towards the bottom somewhat narrower, with very thick brownish-gray dust. Palpi near the root and margin blackish, upon the middle more brownish ; it was not possible to distinguish their color with certainty in the described specimens. Third joint of the antennez very small; arista apical; front quite Opaque on account of a covering of brownish-gray dust. The scutellum and especially the abdomen have very little dust and are shining. The hair upon the abdomen is black. Coxe and femora black, the latter with a very bright green metallic lustre ; the second joint of the fore coxe, the tip of all femora, the tibie and all the tarsi as far as the end of the first joint, yellow; the tip of the tarsi dark brown. The hairs and bristles upon the feet everywhere very short, the bristles at the same time very scarce. Pulvilli of the fore tarsi rather small. Cilia of the tegule whitish. Wings grayish with a rather protruding anal angle; the anterior margin of the wings shows a not very strong, but distinctly visible thickening, which begins abruptly at the end of the first longitu- dinal vein and thence gradually decreases towards the tip of the wing ; the last segment of the fourth longitudinal vein is scarcely a little inflected, parallel with the third, and ends a little before the extreme tip of the wing; posterior transverse vein rather * equidistant from the root and the tip of the wing. Hab. Illinois. (Le Baron.) Observation.—C. subcostatus is easily distinguished from the male of C. costalis by the smaller antenne, the less thickened costa, the thinner cover of dust, and the green metallic lustre of the femora; from all other species it is distinguished by the thickening of the costa. 182 DIPTERA OF NORTH AMERICA. [PART ILI. b. Costa of the male not thickened. 9. C. discolor Lorw. %§ and 9.—Viridis, nitens, femoribus concolori- bus, genibus, tibiis venisque alarum flavis, maris oculis distantibus et abdomine violaceo. Shining green, also the femora; knees, tibiz and veins of the wings yel- low; eyes of the male separated and its abdomen violet. Long. corp. 0.09—0.10. Long. al. 0.10—0.11. Syn. Chrysotus discolor Loew, Neue Beitr. VIII, 65, 6. Male. Shining green. The face rather broad for a male, a little narrower towards the bottom, with yellow-grayish or rather white-grayish dust upon green ground. Palpi rather small, black. The third joint of the antennz not very large with an apical arista. Front with rather thick brownish-yellow dust upon green ground. The upper side of the thorax and the scutellum bright golden- green, the posterior end of the former and the latter sometimes more blue-green. The brownish-yellow dust on the upper side of the thorax is distinct, but not sufficient to conceal the ground- color. The upper side of the abdomen is bright violet, the basis of the first segment and the lateral margin steel-blue or blue-green. Coxe black-green. Femora dark metallic-green. The tip of all the femora and the tibiz yellow; the four anterior tarsi become dusky from the basis so gradually that it is difficult to state where the infuscation begins; on the hind tarsi the yellow coloring ex- tends much farther, so that only the last joints exhibit a distinct dusky tinge. The pulvilli are rather large, especially on the fore tarsi. The hairs and bristles upon the feet are everywhere very short, on the tibie and tarsi yellowish, with the exception of the stronger bristles at the tip of the middle tibiae. The cilia of the tegule are pale. Wings hyaline, scarcely a little tinged with gray, with luteous veins, which become a little more dark towards the tip of the wing; the last segment of the fourth longitudinal vein is parallel to the third and ends exactly at the tip of the wing ; the posterior transverse vein lies rather exactly in the mid- die between the extreme root and the tip of the wing; the anal angle of the wings is rather protruding. female. It differs from the male by the following marks: The face broader, but not too much for a female; the usual transverse swelling is far below its middle. The third joint of the antenne somewhat smaller than that of the male. The abdomen golden- CHRYSOTUS. 183 ereen, without any trace of a violet coloring. The pulvilli of all the tarsi are very small. Hab. Middle States. (Osten-Sacken.) 10. C. auratus Lorw. %.—Viridis, thorace et scutello auratis, polline lutescente subopacis, femorum nigrorum apice tibiisque omnibus flavis, facie latiuscula albido-pollinosa, palpis nigris. Green, thorax and scutellum gilded, somewhat dull on account of a lnteous dust; the tip of the black femora and all the tibiz yellow; the rather broad face covered with white dust; palpi black. Long. corp. 0.11. Long. al. 0,11. Syy. Chrysotus auratus Loew, Neue Beitr. VIII, 65, 7. Metallic-green. Face even for a female rather broad, with gray-white dust; the usual transverse swelling lies very far below its middle. Palpi black. The third joint of the antenne rather large for a female, with comparatively long hair. Front golden- green, rather dull on account of a yellowish dust, only a little broader upwards. ‘The upper side of the thorax greenish-golden, but thickly covered with yellow dust and therefore opaque. Color and dust of the scutellum the same as those of the thorax. Abdo- men of a purer metallic-green and with less dust, near the basis usually more golden-green. Coxe black, the extreme tip of the first joint and the second joint of the fore coxe yellow, the second joint of the hind coxe yellowish-brown. Femora black with in- distinct green or bronze-colored metallic lustre; the tip of the four anterior femora is to a larger, and that of the hind femora to a smaller extent, yellow. The tibize and the tarsi have the same color, but the latter, towards their end, gradually become dusky. The hair upon the feet is everywhere very short, and the bristles very scarce. Cilia of the tegule pale. Wings somewhat grayish with brown veins ; the posterior transverse vein lies about midway between the extreme root and the tip of the wing. Hab. New York. (Osten-Sacken.) B. Femora of a pale color. 11. C. pallipes Lorw. % and ?.—Viridis, nitens, coxis anticis pe- dibusque flavis. Shining green, the fore coxe and the feet yellow. Long. corp. 0.09—0.10. Long. al. 0.10—0.11. “Sy. Chrysotus pallipes Loew, Neue Beitr. VIII, 66, 8. 184 DIPTERA OF NORTH AMERICA. [PART II. Both sexes resemble each other very much. Metallic-green, shining. The eyes of the male meet almost completely, so that the face appears small, linear ; in the female it is broader and has the usual transverse swelling far below its middle. The dust upon it is white in both sexes. The palpi are rather small and covered with whitish dust so as to conceal the ground-color, which appears to be more yellowish than blackish. The third joint of the an- tenne is not large, even in the males, and but little oblique. Front green, rather dull from whitish dust. The upper side of the thorax has a distinct whitish dust, which however does not conceal the ground-color. The black hair upon the abdomen is somewhat longer than in most of the other species. The whole fore coxe, the tip of the middle and hind coxse and the whole feet are yel- low, even the tarsi are only slightly dusky towards the tip. Cilia of the tegule pale. Wings a little grayish, with brownish or brown veins ; the posterior transverse vein lies considerably nearer to the root than to the tip of the wing. Hab. Middle States. (Osten-Sacken.) 42. C. picticormis, nov. sp. %.—Minutus, viridi-aeneus, modice nitens, oculis infra antennas coutiguis, primo antennarum articulo rufo, coxis anticis pedibusque flavis. Small, bronze-green, moderately bright ; the eyes contiguous below the an- tenn; first joint of the antenne red; fore coxe and the feet yellow. Long. corp. 0.08. Long. al. 0.08. Very small, bronze-green, moderately shining. The eyes con- tiguous below the antenne. The antenns small, the first joint red, the following two black, the third rather small and a little oblique; arista apical. Fore coxe and feet somewhat brownish- yellow. The tip of the hind femora on the upper side and all the tarsi from the tip of the first joint, brown. The hind tibiz are fringed on the upper side only with a few delicate, not very con- spicuous bristles, and show a dusky tinge at the tip. The color of the cilia of the tegule I cannot positively state. Wings of the usual structure, grayish-hyaline with brownish-black veins; the posterior transverse vein is rather short and lies before the middle of the surface of the wings. Hab. Wlinois. (Le Baron.) Observation.—This description is made only after a single spe- TEUCHOPHORUS.—SYMPYCNUS. 185 cimen, and will probably require some correction ; the color of the first joint of the antenne is so characteristic for this species, that there is no probability of its being mistaken for another. Gen. XXXI. TEUCHOPHORUS. The genus Teuchophorus remains hitherto confined to but a few European species. They rather resemble the small species of Chrysotus, but are easily distinguished from them by the follow- ing characters: Antenne smaller; arista distinctly dorsal. The abdomen of the male somewhat compressed laterally. The pos- terior transverse vein, which is far distant from the margin of the wing, has an extremely steep position, so that its posterior end is farther from the root of the wing than its anterior end. The feet of the male are fringed with isolated, strong, stiff bristles, and its hind tibie are curved and adorned in various manners. Besides, in all the hitherto known species, the costa of the male is thickened in the same manner as that of the previously described C. costalis. The other characters of the genus coincide with those of Chry- sotus. The name of the genus (from vevyos, armor, and ¢épw, I bear) has probably reference to the peculiar organs with which the male is provided. Gen. XXXII. SWMPYCNUS. Characters. Small, but little shining species, of a rather slender shape. The face is not narrower upwards. Antenne rather small, in the female shorter than in the male; the first joint with- out hairs; the arista is inserted upon the edge of the third joint in the vicinity of its basis. The metathorax is not unusually pro- truding nor elongated. The abdomen of the male is more or less compressed laterally. The hypopygium is small, more or less im- bedded ; its outer appendages small, sometimes not distinctly visi- ble. The fourth longitudinal vein, towards its end, is perceptibly, although only slightly, approximated to the third and very little convergent towards it ; it ends somewhat before or into the tip of the wing ; the posterior transverse vein before or upon the middle of the wing, distant from its margin; the sixth longitudinal vein becomes indistinct long before it reaches the margin of the wing. 186 DIPTERA OF NORTH AMERICA. [PART II. The feet are sparely fringed with bristles; the hind tarsi shorter than the hind tibiz and their first joint without bristles. The genus Sympycnus stands in the closest proximity to Anep- sius, is, however, very easily distinguished from it by the glabrous- ness of the first joint of the antenne. Among the genera which have no hair upon the first joint of the antenne, Xanthochlorus, Teuchophorus and Campsicnemus are the next to it; they differ ° from Sympycnus by the following characters: 1. Xanthochlorus by the depression on the posterior end of the thorax and the pre- vailing yellow color of the body and of the bristles upon the thorax ; 2. Teuchophorus by the steeper position of the posterior transverse vein, the thickening of the costa in the male, the isolated and strikingly strong bristles upon the feet and the entirely hidden hypopygium ; 3. Campsicnemus by the elongated metathorax, by the last segment of the fourth longitudinal vein, which is parallel to the third and ends always beyond the tip of the wings and by the face of the male, which is very narrowed upwards, &e. The name of the genus (from ovunvxvos, crowded together) has reference to the crowding together of the ends of the fourth and the third longitudinal veins, whereby Sympycnus is distinguished from Campsicnemus and many other related genera. | I am only acquainted with species from Europe, Africa and North America; the majority of the North American species differ from the European and from the South African species by the fourth longitudinal vein ending exactly into the tip of the wing, while in the other species, this end is distinctly before the tip. As they agree in all other details of organization, there is no ground for a generic separation, but it would be advisable to form of them a group within the genus Sympycnus. The charac- ter of the genus Sympycnus, as hitherto established, requires, with regard to these species, a slight modification, which I have. already introduced. ) | Table for the determination of the Species. 1 tertianus, nov. sp. 9 Fourth longitudinal vein ending before the tip of the wing. ; Fourth longitudinal vein ending into the tip itself. a f Antenne entirely black. 2 frontalis Lw. Antenne pale near the basis. 3 | Thorax with dark longitudinal lines. 3 lineatus Lw. Thorax without dark longitudinal lines. 4 nodatus Lw. SYMPYCNUS. 187 Systematical arrangement of the Species. I. The fourth longitudinal vein ending before the tip of the wing. 1. tertianus, 0. sp. II. The fourth longitudinal vein ending into the tip itself. 2. frontalis Lw. 4. nodatus Lw. 3. lineatus Lw. Description of the Species. I. THE FOURTH LONGITUDINAL VEIN ENDING BEFORE THE TIP OF THE WING. 1. S. tertiamus, nov. sp. % and 9.—Ex cinereo virescens, sub- opacus, thorace non lineato, duobus primis antennarum articulis, pal- pis, ventre, coxis pedibusque dilutissime flavicantibus, tarsis inde ab articuli primi apice nigricantibus. *,. Articulo tarsorum posticorum tertio abbreviato et prope apicem pilis paulo longioribus hirto. ©. Pedibus simplicibus. Gray-greenish, rather dull; thorax without dark lines; the first two joints of the antenne, palpi, venter, coxe and feet pale-yellowish ; the tarsi from the tip of the first joint blackish. *. The third joint of the hind tarsi shortened and rough on account’ of some longer hairs near the tip. Q. Feet plain. Long. corp. 0.10. Long. al. 0.10. Dark grayish-green, rather dull. The front seems to be of the same color. Face grayish. Palpi and the first two joints of the antennz white-yellowish ; the third joint blackish, in both sexes rather rounded. Arista in both sexes plain. Venter whitish-yel- low as far as its tip. The hypopygium, as in the other species of this genus, rounded and semi-imbedded ; its lancet-shaped exterior lamella small, but distinctly perceptible and of rather dark color. The posterior margin of the pleurz and the cox white-yellowish ; the four posterior coxee near the basis more or less infuscated. Feet white-yellowish, with black, somewhat scattered hairs, on the middle and the hind tibize with a few black bristles. The tarsi from the tip of the first joint very much infuscated, the hind tarsi from the same spot almost entirely black. The joints of the fore tarsi of decreasing length in the female, while in the male the third and fourth joints are of about the same length. The joints of the middle tarsi are of decreasing length in both sexes. The first joint of the hind tarsi is, in both sexes, a little shorter than 188 DIPTERA OF NORTH AMERICA. [ PART II. the second; the following joints are, in the female, of decreasing length ; in the male the third joint is somewhat shorter than the fourth, and at its end, on the posterior side, beset with longer black hairs. Wings towards the basis very much narrowed; the posterior transverse vein is before the middle of the disk of the wing, but rather exactly in the middle between the extreme root and the tip of the wing; the fourth longitudinal vein ends some- what before the extreme tip of the wing; in the female, however, at a very small distance from it. Hab. Sitka. (Sahlberg.) IJ. THE FOURTH LONGITUDINAL VEIN ENDING INTO THE TIP OF THE WING. 2. 8. fromtalis Lozrw. % and ?.—Nigricans, fronte lete violaceo splendente, antennis totis nigris. Blackish; the front bright violet; the antennez entirely black. Long. corp. 0.11. Long. al. 0.12—0.13. Syn. Sympycnus frontalis Lorw, Neue Beitr. VIII, 67, 1. Face in the female of moderate breadth, in the male below very narrow, towards the antenne broader, with white dust, so that the blue ground-color becomes very little visible. Antenne black, larger than in the next following species; the first joint rather long; the third joint only with a very short pubescence, larger and ovate in the male, smaller and rather rounded in the female. Front bright steel-blue or violet. Cilia of the inferior orbit whitish. Upper side of the thorax dull on account of a thick e@ray-brownish dust, nevertheless the green or blue ground-color is distinctly visible through the dust. The scutellum is of the same color as the upper side of the thorax, and has no hairs besides the usual bristles. Abdomen black or greenish-black, the second segment usually with a complete or almost complete yellowish transparent transverse band, the third segment with one, which is interrupted in the middle; moreover the first and fourth segments are usually yellowish-transparent on the lateral margin. The venter is always white-yellowish. The hypopygium, of the same color as the abdomen, is somewhat larger than in the other species of this genus known to me, and but very little im- bedded ; its outer appendages are so small and hidden that I can- not distinctly perceive their shape. The posterior margin of the SYMPYCNUS. 189 pleuree, all the coxe and the feet yellowish. Fore coxe only with pale hairs. ‘The femora have, besides the usual small bristles im- mediately before the tip, no other bristles. The fore tibiz are without bristles, the middle and hind tibis with but few bristles. The fore tarsi are more or less infuscated towards their tip; in the female the joints are of decreasing length, the first nearly as long as the three following together ; in the male, on the contrary, the first joint is extremely shortened and not quite as long as the last one, the second almost as long as the two following together, the third considerably shorter than the fourth joint, which latter is fringed on its upper side with little curved hairs. The joints of the middle tarsi, which towards their end become more and more dusky, are of decreasing length in the female; in the male their first joint is considerably longer than the following four joints together, the second as long as the following three together, tie third and fourth of almost equal length, but very short, on the anterior side bearded with delicate little fringe-like hairs; the fifth jot is somewhat more slender than the two preceding joints and almost as long as these taken together. The hind tarsi, from the tip of the first joint, are more or less infuscated, the first joint much shorter than the second, and the following joints of decreas- ing length in both sexes. The tegule with pale-yellowish cilia. Wings rather long and narrow, but moderately pointed towards the root, in the female less tinged with gray than in the male; the fourth longitudinal vein is parallel with the third and ends rather exactly into the tip of the wing; the posterior transverse vein is perpendicular and lies before the middle of the wing. Hab. Pennsylvania. (Osten-Sacken.) 3. S. lineatus Lorw. 4% and 9.—Cinereus, fronte nigra, antennarum basi, scutelli margine, ventre pedibusque flavis. Gray, front black; the root of the antenne, the margin of the scutellum, the venter and the feet yellow. Long. corp. 0.10—0.11. Long. al. | 0.11—0.12. Syy. Sympycnus lineatus Lozw, Neue Beitr. VIII, 67, 2. Brownish-cinereous, opaque. Face covered with whitish dust upon black ground ; in the female it is rather narrow, in the male so much narrowed that the eyes are contiguous on the lower part of the face. Palpi rather blackish. Antenne rather short, the 190 DIPTERA OF NORTH AMERICA. [PART II. third joint smaller than in the next preceding species, in the male elongated-ovate, in the female considerably shorter, in both sexes with a basal arista; the first joint is always of a yellowish color, the two following paler or darker brown, sometimes rather black- ish. Front black. Cilia of the inferior orbit pale. Upper side of the thorax brownish-cinereous, entirely opaque; the humeral corner usually brownish-yellow ; on its upper side there are several dark longitudinal lines, the more distinct of which are usually a delicate middle line and two stronger lines alongside of it; the latter bear the middle rows of bristles. These lines disappear, however, when looked upon from another direction, and are not equally distinct and sharply defined in all specimens. Scutellum on the middle of the upper side gray with a metallic-blue lustre, on the margin yellow. Pleure gray, their inferior portion more yellow. The metathorax blackish-gray. Abdomen in well colored specimens brownish-gray, in less matured ones more yel- lowish-brown ; the whole venter always pale-yellowish. The small hypopygium is mostly shining black and rather imbedded; the outer appendages are larger than usual in the species of this genus aud have almost the form of small filiform lamelle; their color is a dingy yellowish-brown. Coxe and feet yellowish. Femora only with the usual bristles immediately before the tip. Fore tibiee without bristles. Middle and hind. tibia with a moderate number of short black bristles. The first joint of the fore tarsi about as long as the three following, which are of decreasing length, most of the fourth and the whole fifth joint black-brown. Middle tarsi from the tip of the first joint more or less dusky ; their first joint about as long as the four following together, which are of decreasing length. ‘The first joint of the hind tarsi much shorter than the second, the following of decreasing length. Tegule with brown margin and with pale-yellowish cilia. -Wings tinged with gray, in the male with a cuneiform tapering towards the basis; this is not the case in the females ; the fourth longitu- dinal vein is parallel with the third and ends rather exactly into the tip of the wing; the posterior transverse vein is perpendicular aud lies rather upon the middle of the wing in the female, consi- derably beyond it in the male. Hab. Virginia; New York. (Osten-Sacken.) SYMPYCNUS. 191 A. S. modatus Lorw. % and 9.—Cinereus, margine primi antenna- rum articuli infero, fasciaé abdominis basali maculisque lateralibus, ven- tre et pedibus flavicantibus, femorum posticorum apice nigro, seta an- tennali maris capitulum minutum apicale gerente. Gray, the lower margin of the first joint of the antenna, a band near the basis of the abdomen, lateral spots upon it, venter and feet, yellowish ; the tip of the hind femora blackened ; the arista of the male at the tip with a small button. Long. corp. 0.10—0.11. Long. al. 0.11—0.12. Syn. Sympycnus nodatus Loew, Berl. Ent. Zeitsch. V1, 215, 68. Face of the male very narrow, upwards a little broader, with white dust; the face of the female much broader, not perceptibly narrowed below, and much less thickly dusted, so that the black ground-color is distinctly apparent. Antenne of a stouter struc- ture, and even a little larger than in S. frontalis ; the first joint rather long, upon the under side always of a yellowish color, some- times yellow, with the only exception of its upper edge, in which case the yellow coloring extends also on the lower edge of the second joint; the third joint in the male is broad ovate, in the female rounded. Arista basal, in the female somewhat shorter and plain, in the male longer and enlarged at the tip into a small button. The front is gray, but appears in some directions almost black. Upper side of the thorax brownish-gray, opaque, without distinct longitudinal lines, with black bristles. Scutellum usually darker than the upper side of the thorax and without hairs, except the usual bristles. Pleure whitish slate-gray, “their posterior margin yellowish. Abdomen of a bronze-black, moderately bright coloring, sometimes with a green or blue metallic lustre ; upon the second segment there is a very broad, usually inter- rupted, transverse band; upon the third segment there is also a transverse band, usually interrupted in the middle, and consisting of two yellow lateral spots; the fourth segment has usually a yel- low spot on each side. The hypopygium, being of the same color as the abdomen, is of a similar structure as in S. frontalis ; its small, not easily perceptible, appendages are black. Coxe and feet yellowish. The fore coxe are covered only with whitish hair, nevertheless the stronger hairs on the tip assume sometimes a blackish appearance. The femora without any other bristles but those small ones, usually found before the tip; the hind femora are of a brownish-black color to a rather large extent, though their extreme tip is again paler. The fore tibiz have only a single 192 DIPTERA OF NORTH AMERICA. [PART II. small bristle, which is on their upper side, not far from the root ; the middle tibise have only a few bristles; the hind tibiz have a larger number of bristles, but they are mostly very short ; in the male there is one bristle on the under side, not far from the basis, which is remarkable for its length. The fore tarsi have 14 the length of the tibia; in the male the first joint is very much shortened and not as long as the last one, the second is as long as the three following together, and usually a little blackened on the extreme tip, the three last ones are black and very little decreasing in length; the last one with somewhat shorter hairs than the two preceding ; in the female the fore tarsi are gradually of a darker black-brownish color towards the tip, and their joints are of a de- creasing length, the first somewhat longer than the two following, but not quite so long as the three following together. The mid- dle tarsi of the male but little exceed the tibiae in length; their first joint is of a plain structure, but almost 14 the length of the other joints and blackened at its tip ; the last four joints are black; the second is as long as the last three together, gradually enlarged towards its end, and at the end on the outside, in consequence of the greater length of the appressed black pubescence, elongated into a kind of projection ; the third and fourth joints have on the posterior side a few erect crooked hairs. The middle tarsi of the female are plain, scarcely shorter than those of the male, towards the tip gradually of a darker black-brown color; their joints are of a decreasing length; the first is longer than the following two, but shorter than the following three together. The hind tarsi are of the same structure in both sexes, shorter than the tibie ; their last four joints black; the first joint is scarcely longer than the third, the second at least as long as the third and fourth together. Hal- teres yellowish. Tegule with a narrow black margin ; their cilia appear yellowish in a reflected light, seen towards the light, however, blackish, in the female even often black. Wings grayish hyaline, in the male with the posterior margin somewhat wavy, and towards the basis much more pointed than in the female ; the fourth longi- tudinal vein is parallel to the third and ends precisely at the tip of the wing; the posterior transverse vein is perpendicular and lies upon the middle of the wing. Hab. Mlinois. (Le Baron.) CAMPSICNEMUS. 193 + Gen. XXXII. CAMPSICNEMUS. racters. The first joint of the antenne without hairs on the side » the third more or less pointed, distinctly hairy; the inserted on its back, near the basis. Face upwards very , especially in the male. The metathorax is elongated ; domen flattened. The small hypopygium imbedded; its ages extremely small. Feet slender; the first joint of the rsi without bristles. The males are usually remarkable by uliar structure of their tibie and often also ‘of the tarsi: = segment of the fourth longitudinal vein, about its first runs over a distinct convexity of the wing, is parallel to | longitudinal vein and ends beyond the tip of the wing. renus Campsienemus possesses so many remarkable cha- hat the species belonging to it cannot either be mistaken unded with species of another genus. The name of the rom xapjes, the curve, and xryjun, the tibia) was given be- e males of many species are distinguished by the peculiar e of their middle tibiz. yecies hitherto known belong to Europe and North Ame- Description of the Species. irtipes Lorw. % and 9.—Obscure olivaceus, facie ochracea, Scatis, coxis anticis pedibusque ex testaceo rufis, tarsis preter < fusco nigris. tibiarum intermediarum dimidio incrassato, tarsisque anticis giores gerentibus. $ simplicibus. brown, face ochre-colored ; wings blackish-gray ; fore coxe ana nish-red ; tarsi black-brown with the exception of the root. kened basal half of the middle tibie and the fore tarsi beset bristles. in. Long. corp. 0.08. Long. al. 0.13. tenemus hirtipes Loew, Neue Beitr. VIII, 68, 1. olive-brown. Face very narrow, yellowish-brown, ht golden-green spot immediately under the antenne, t always easily discernible. Antenne entirely black ; oint in the male long and pointed, in the female short 194 DIPTERA OF NORTH AMERICA. [PART II. and small. Front black with a violet, oftgn very bright lustre, immediately above the antenne with a pale copper-reddish spot. The cilia on the inferior orbit pale. The upper side of the thorax often shows violet reflections. The scutellum shining violet, rarely shining black with an indistinct violet lustre. The color of the abdomen is usually more greenish-black. Fore coxe brown- ish-yellow, near the basis blackened ; middle and hind coxe black with brownish-yellow tip. Feet yellowish-red or brownish-red. The extreme tip of the knees blackish-brown and the tarsi from the tip of the first joint black. Sometimes the upper side of the femora is distinctly infuscated. Cilia of the tegule black. , | Wings tinged with blackish-gray and with black veins; the convexity of the wings lies before the first quarter of the last segment of the fourth longitudinal vein. Male. Its fore femora are thickened as far as their middle, and on the under side, precisely at the end of this thickening, they are densely bearded with stiff little bristles; the fore tibie are visibly stouter than in the female, beset on the under side with numerous and erect, on the upper side with less numerous and less erect bristles ; fore tarsi with unusually long hairs, especially on ther first two joints. The structuve of the middle femora is similar to that of the fore femora, though their thickening is less strong and reaches as far as the tip; the thick beard on the under side, formed of short stiff bristles, is thus brought nearer to their end. “he middle tibie are of rather irregular structure; from the basis to about their middle they are distinctly thickened and fringed on the upper side with a few long black bristles, on the under side chey are provided with a small tubercle, beset with short bristles. That part of the middle tibize, which is not thickened, is of a plain s;ruc- ture, though beset on the under side with a row of rather long, black, bristle-like hairs. The middle tarsi and the whole hind feet are of a plain structure. Hab. Pennsylvania. (Osten-Sacken.) 2. C. claudicams, nov. sp. % and 9.—Olivaceus, facie ochracea, alis infuscatis, punctum nigrum in ultimo vene quarte segment) geren- tibus, coxis anticis ex testaceo fuscis, pedibus ex rufo testaceis. ; %. Tibiis intermediis crassissimis, varis, supra nigro-spinulosis, tarsis in- termediis totis nigris, articulo primo crasso, recurvo, supra nigro-setoso, tarsis anticis posticisque simplicibus, inde ab articuli primi apice nigris. ®. Pedibus simplicibus, tarsis omnibus inde ab articuli primi apice nigris. CAMPSICNEMUS. 195 Olive-green; the face ochre-yellow; wings infuscated, with a black spot upon the last segment of the fourth longitudinal vein ; fore coxe red- dish-brown ; feet brownish-red. %,. Middle tibie very stout, crooked, on the upper side with small black spines; the middle tarsi entirely black; their first joint thickened, curved upwards, on the upper side with black bristles; fore and hind tarsi plain, from the tip of the first joint black. ©. All the feet plain; all the tarsi from the tip of the first joint, black. Long. corp. 0.09. Long. al. 0.14. Olive-green; thorax more bright than the abdomen, near its fore margin with a few strikingly green reflections. Front black- ish-blue. Antenne entirely black; the third joint small and not pointed. Face brownish ochre-yellow. Palpi ochre-brownish. Proboscis black. Cilia of the posterior orbit black above, below pale. Fore coxe brownish-red, sometimes yellowish-red, with a white reflection near the root and a large part of the outside brown; the four posterior coxse grayish-black, the trochanters brownish-black. Feet yellowish-red; the knees, especially those of the hind feet, more or less infuscated ; all the femora, the fore and hind tibiz, as also the fore and hind tarsi are plain in both sexes, the latter blackened from the tip of the first joint. The middle tibis and middle tarsi are only in the female of the same plain structure and of the same color, while they are distinguished in the male by a very different structure; for its middle tibiz are uncommonly stout and somewhat curved; the greatest thickness is in their middle; the last two thirds of the posterior side are excised and provided with a brown stripe ; before this excision, almost on the upper side of the tibia, there is a longitudinal row of black spine- like bristles, which does not occupy, however, the basal third and the apical one-fourth of the tibia; the second half of the tibia bears upon the other two sides a few long black bristles; the middle tarsi of the male are entirely black; their first joint is somewhat curved upwards at the tip, stout and near the extreme basis a little more swollen, on the upper side excised furrow-like and fringed with a row of black bristles; the following joints are plain, the second not quite so long as the third, and at the extreme basis sometimes of a yellowish-brown color. Wings with a dis- tinct smoky black tinge and with a small blackish spot upon the last segment of the fourth longitudinal vein. Hab. Sitka. (Sahlberg.) 196 DIPTERA OF NORTH AMERICA. [PART If. Gen. XXXIV. PLAGIONEOURUS. This genus has been established by me (in the Wien. Entom. Monatschr. I, 43) on the species described below, and known as yet only in the female sex, but the extraordinary and peculiar cha- racters of which rendered the establishment of a new genus neces- sary. The whole habitus approaches the species of Gymmnopter- nus and Pelastoneurus most, differs, however, from both by the first joint of the antenne being entirely without hairs and by the posterior transverse vein having an unusually oblique position ; from Gymnopternus it differs moreover by the course of the last segment of the fourth longitudinal vein, which is almost like that of the genus Pelastoneurus. The peculiarities of the female seem to indicate that the hypopygium of the male is disengaged. The establishment of the characters of this genus on so scanty materials presents many difficulties. I believe, however, that the following may be regarded at least as a temporary definition. The first joint of the antenne without hairs, the second not reach- ing thumb-like over the third, on the upper side much longer than on the under side; the third joint short, without distinet hair and with a dorsal arista. The posterior transverse vein very oblique; the last segment of the fourth longitudinal vein runs much forward in its second portion and ends in the vicinity of the third longitudinal vein, so that the first posterior cell becomes very narrow near its end. The first joint of the hind tarsi is without bristles. The name of the genus (from anrdyios, oblique, and vetpor, the nerve) has reference to the extraordinary obliqueness of the pos- terior transverse vein. 1. P. univittatus Lorw. 9%.—Viridis, thoracis vitt&é media abdo- minisque fasciis latis purpureis, antennis pedibusque nigris, femoribus virescentibus, genibus tibiarnmque anteriorum basi testaceis, alis cinereis. Green, middle stripe of the thorax and broad bands of the abdomen of a purple color; antenne and feet black, the knees and the basis of the four anterior tibie dusky yellow; wings gray. Long. corp. 0.25. Long. al. 0,23—0.24. | Syn. Plagioneurus univittatus Loew, Wien. Ent. Mon. I, 43.—Lozw, Neue Beitr. VIII, 69. PLAGIONEURUS. 197 Face not very broad for a female, somewhat elevated, upon its larger upper part with an impressed middle line ; the smaller, con- vex lower part is separated from the upper part by a transverse swelling, incomplete in its middle ; the dense, almost silvery-white dust, conceals a great deal of the ground-color of the face. An- tennz black. The third joint with a short, but sharp tip; the arista rather strong, with a very short but distinct pubescence. Front bright metallic blue-green. The cilia on the upper orbit black, on the entire lateral and lower orbits white. Thorax me- tallie-green, only on the fore and lateral margin with a little whitish dust, upon the middle with a not very sharply defined longitudinal stripe, which in some directions appears more black, in others more brown and purple, sometimes of a beautiful cinna- mon-brown color. Scutellum metallic-green, with the usual two strong bristles, otherwise bare. On the segments of the abdomen the two first thirds have a dark, the last third a more pale color; the eolor of the former part shifts from black, through bronze- brown into a beautiful dark violet; on the last third the color is chiefly metallic-green, nevertheless it changes on the anterior part into steel-blue, and on the hind margin of the segment into golden- green or almost a coppery color; onthe lateral margin the last third of the segments is covered with white dust. Coxe black with a rather dusky-green lustre; the foremost with white dust, clothed with delicate white little hairs, and at the tip with a few black bristles. Feet black; femora with green lustre; knees brownish-yellow ; this coloring extends on the fore tibiz as far as the middle, on the middle tibiz as far as the first third, while on the hind feet it is confined to the tip of the knee. The femora have on the under side from the basis almost as far as the tip, erect, but short, whitish hairs ; otherwise their hair is black ; mid- dle and hind femora have on the front side before the tip a few insignificant black bristles. The hair upon the tibie is altogether black, very short, only on the upper side of the hind tibize some- what longer, so that its great density is easily perceived; all the tibiz are beset with short and not very numerous black: bristles.. Wings tinged with smoky gray, the veins brown-black; the pos- terior transverse vein is so very much oblique as to run parallel to the hind margin of the wing; the last segment of the fourth longitudinal vein approaches the margin of the wing rather closely, without changing its course, then, however, it suddenly turns 198 DIPTERA OF NORTH AMERICA. [PART II. towards the front, so as to end rather far from the tip of the wing in the vicinity of the third longitudinal vein. Hab. Cuba. (Riehl.) Observation.—This species is also found in Brazil. Gen. XXXV. LEIANCALUWS. The genus Liancalus shows the closest relationship to the genera Scellus and Hydrophorus. It agrees with them in the following characters: The body in general is beset with neither numerous nor long bristles. Wings elongated; the posterior transverse vein very closely approximated to the margin of the wing ; feet elongated and slender; the first joint of the hind tarsi on the upper side without bristles, not shorter than the second, but in the majority of the species, longer. Face in both sexes broad, provided with a small tubercle upon the lowest third of each side of the orbit, and with an indistinct swelling running from one tubercle to the other. Antenne rather short, the first joint without hairs; the apparently bare arista ‘dorsal, distinctly two- jointed. The hypopygium of the male imbedded. The above mentioned three genera differ sufficiently from the other genera of the Dolichopodidz by the above stated characters, which they have in common. The genus Liancalus in particular, however, differs from SceNus and Hydrophorus in the following points: 1. All the femora are slender and unarmed, while the genera of Scellus and Hydrophorus have the femora very much thickened toward the basis, which at least in the males, is armed on the under side; 2. The segments of the abdomen are beset with bristles before the posterior margin, which is not the case in the species of Scellus and of Hydrophorus. The genus Liancalus contains as yet only three European and one North American species. They form two groups; in the first the scutellum has only four bristles and the exterior appendages of the hypopygium are more lamelliform, while in the second the scutellum has six bristles and the exterior appendages of the hypopygium are fliform. To the first group belongs Liancalus lacustris Scop. and leucostomus Loew, to the second L. virens Seop. and the following North American species. The name of the genus (from aeos, smooth, and ayxday, arm) - LIANCALUS. 199 has reference to the unarmed fore feet, by which it is distinguished from the next related genera of Scellus and Hydrophorus. I. L. gemualis Lorw. % and ?.—Virescens, thoracis lineis quatuor abdominisque fasciis obscuris, pedibus ex nigro viridibus, genibus flavis, alis maris macula apicali nigra, guttam candidam includente, ornatis. Greenish, four lines upon the thorax, and the bands upon the abdomen dark, feet blackish-green with yellow knees; the tip of the wing in the male with a black spot, which contains a snow-white drop. Long. corp. 0.26—0.28. Long. al. 0.31. Syn. Liancalus genualis Loew, Neue Beitr. VIII, 70, 1. Closely related to the European ZL. virens Scop. and very much like it, though differing from it in the neuration and the picture of the wings, as also by the greater length of the filiform append- ages of the hypopygium. Blue-greenish, somewhat gray from pale dust. Face green or blue with rather whitish dust, which, how- ever does not conceal the ground-color. The large black palpi, fringed with black and comparatively long hair, when seen from the side, usually appear entirely gray-yellowish on account of the dust, with which they are covered. Front green and somewhat spotted with whitish dust. Antenne entirely black. The cilia of the posterior orbit black above, whitish below. The upper side of the thorax has two narrow, linear longitudinal stripes, separated by a reddish-gray middle line; these stripes are rather black in fully colored specimens ; there are besides two latera stripes, the posterior part of which is bifurcated near the trans- verse suture. Thus, not much is left of the beautiful blue-green color, except two broad longitudinal stripes, bearing the stronger bristles. Scutellum with six bristles, as in L. virens. The ab- domen is provided with broad, copper-colored or bronze-brown, sometimes almost black, transverse bands, on the posterior margin of the segments; on the edge of these bands the ground-color of the abdomen changes often into yellowish-green. Coxe, femora and tibie metallic black-green ; the knees yellow; the tarsi black. Fore coxe elongated, cylindrical, on the front side with long whitish hair, at the tip only with a few small black bristles. In the male the second joint of the fore tarsi is uncommonly short- ened and somewhat thickened, so as to be the shortest of all joints, and almost as broad as it is long. Cilia of the tegule whitish. 200 DIPTERA OF NORTH AMERICA. [ PART Il. Wings with black veins, hyaline, in the female with but few irre- gular gray spots upon the apical half, in the male moreover near the tip with a few grayish-black longitudinal stripes, and on the tip itself with a black spot, containing near the end of the fourth longitudinal vein anteriorly a round drop, which, the light falling through it, has a snow-white reflection; on the anterior margin of this drop, in the black, there is always a small paler spot. The outline of the wings in the male differs considerably from that of the female, being not only narrower, but also sinuated on their whole posterior margin in a peculiar manner. The ex- terior appendages of the short black hypopygium are two very long threads, which reach back almost as far as the basis of the abdomen, and which are beset on their whole length with very long pale hairs. Hab. Middle States. (Osten-Sacken.) Gen. XXXVI. SCELLUS. Characters. First joint of the antenne comparatively narrow, bare; the second short; the third rounded, elongated only in a hitherto undescribed European species, not excised on the edge. Arista dorsal, apparently bare, distinctly two-jointed. The front on the vertex but little deepened, a little narrower anteriorly. The eyes much higher than broad, encased below by the linear cheeks. Face of middling breadth, very long, reaching somewhat below the lower corner of the eye; its lowest sharply-edged part is separated from the narrowly-margined eyes by an incision, which turns away from the eyes on its upper end. Palpi recum- bent, of middling and about equal size in both sexes. Proboscis stout. Upper side of the thorax upon its middle with but short bristles. Scutellum flat, with two bristles. Abdomen with- out bristles and only with scattered and very short hairs. The abdomen of the male has five segments ; the first four are normally developed, while the fifth is usually shortened, often also of a different color; the following segment is formed by the short, half-imbedded hypopygium. At its lower end there are two small, dark lamell, directed obliquely downwards, which lie so close together as to present the shape of a stout, dentiform pro- jection ; besides these, the comparatively thick penis, bent down- ward and curved, may be seen, but no other appendages. Between * SCELLUS. 201 the fourth and fifth abdominal segments of the male, however, two long, mostly pale-colored tape- or thread-like appendages protrude, which are turned either backward or outward; their place of in- sertion seems to forbid us to take them for representatives of the ordinary external appendages of the hypopygium ; thus, we are led to regard as such the previously mentioned inferior appendages ; if we do this, then the representatives of the interior appendages will be wanting, unless these same tape- or thread-like appendages are taken for them. If the point 6f insertion of the tape-like appendages was really at the place where they first appear on the outside, then the question would be solved, as in such a case they could not be considered as appendages of the hypopygium ; that however, this is not the case, and that they rather originate much further inside, and proceed from there upwards between the fourth and fifth abdominal segments, before they reappear on the surface, can be distinctly seen in many specimens; to ascertain their true place of insertion requires the anatomical examination of fresh specimens, for which I have no opportunity at present. The form and position of the hypopygium and of its appendages in the males of Scellus has so many peculiar features, that it is difficult to arrive at a conclusion about the true meaning of its different parts. The female abdomen consists of five normally developed segments, followed by one segment more, which is shortened, retracted, and of a different color; the extreme, somewhat opaque tip of the female abdomen is beset with black bristles. The feet are generally bare, middle and hind feet much longer than the fore feet, and, except the thickening of their femora, which belongs to the males of some species, they are more slender than the fore feet; fore femora thickened towards the basis, on the under side with nume- rous bristles ; fore tibiae on the under side with bristles, elongated at the end into a large tooth, which is still larger in the males than in the females; the males have, moreover, a strong spine on the inside, not very far from the basis; the middle tibie of the male are variously decorated with long curly hairs and stiff bris- tles, while those of the female are plain; the hind tibize and the. feet in both sexes plain, the joints of the latter of decreasing length; the empodium distinct. Wings long and narrow; the posterior transverse vein oblique and close to the margin of the wing; the third and fourth longitudinal veins converging, the 202 DIPTERA OF NORTH AMERICA. [PART II. sixth almost entirely obliterated or existing only as but a short rudiment. In the genus Liancalus we have already mentioned the charac- ters which this genus has in common with Scellus and Hydro- phorus, as also those which distinguish Scellus from Liancalus ; to the latter may be added the presence of the two appendages, peculiar to the males of Scellus. The presence of these append- ages also distinguishes the species of Scellus from Hydrophorus, where they are entirely wanting. Moreover the under side of the fore femora and of the fore tibise in the species of Scellus is beset with long spines, catching into each other when the knee is bent, while in the species of Hydrophorus there are at the utmost some spine-like bristles on the under side of the fore femora near the basis, otherwise the under side of the fore femora and of the fore tibiz is only beset with very short thorn-like bristles. The name of the genus (from oxeaads, with crooked feet) has reference to the peculiar structure of the fore feet. I know as yet only six species of Scellus, of which three are peculiar to North America, one is common to Europe and North America, and two are exclusively European; one of the latter species, occurring in Sweden, is as yet undescribed. Table for the determination of the Species. 1 { Wings entirely blackened. 1 exustus Walk. Wings not entirely blackened. ae Apical half of the wings black. 2spinimanus Zit. { Apical half of the wings not black. 3 3 ' Wings entirely tinged with blackish gray. 3 avidus, n. sp. Wings scarcely a little tinged with gray. 4 filifer, n. sp. Description of the Species. i. 8. exustus Watk. % and 9.—Thoracis dorso eneo-nigro opaco, abdomine cupreo, latera versus viridi, nitidissimo, halteribus nigris, alis nigricantibus adversus costam nigris, lamellis analibus maris albis, in basi nigris, apicem versus flavis, in summo apice puncto nigro notatis. The upper side of the thorax bronze-black, opaque; the abdomen copper- colored, laterally green, very bright; halteres black; wings blackish, towards the fore margin entirely black ; the anal appendages of the male are white, near the root black, towards the tip yellow, at the extreme tip with a black spot. Long. corp. 0.22. Long. al. 0.26. Go SCELLUS. 20 Syn. Medeterus exustus WALKER, Dipt. Saund. 211. Scellus exustus Lozw, Neue Beitr. VIII, 71, 1. Male. Black. The face rather narrow, opaque from a bright ochre-yellow dust. Antenne black. Front covered with white dust. The middle of the upper side of the thorax is, at least in my specimen, black, opaque, and exhibits some traces of gray dust; towards the lateral margin it is more bright and shows a less distinct coppery reflection ; on the lateral margin itself there is a broad longitudinal stripe covered with white dust. Scutellum with two bristles, opaque upon the middle, with a thin, almost im- perceptible coat of white dust, bright on the sides. Pleure bronze-black, on the upper half with a dusky copper-colored reflec- tion, on the lower half with a thin gray-whitish dust. Abdomen brilliant coppery-red, in a certain light it appears brass-colored upon the posterior segments, in an oblique direction even green ; its first segment almost reddish-violet. The upper appendages, peculiar to the males of Scellus, are of a very considerable length, white, near the root black, somewhat enlarged at the tip, curved towards each other and of a yellow color, at the extreme tip black and provided with a tuft of pale hairs, which are turned back- wards. Coxe black, with a thin white-grayish dust, the foremost with extremely short pale hairs, with a few stiff black little hairs and near the tip with a few black bristles. Feet black, the femora more metallic green-black, with coppery reflections; ‘the fore femora but short,.very much thickened, toward the basis on the whole under side beset with bristles of different length, on the an- terior side with a row of stiff black bristles ; middle femora elon- gated, thin, gently curved, on the under side almost entirely bare ; the hind femora near the basis of the under side are enlarged into a large blunt appendage, beset with large black spines, beyond this appendage there is an arch-like excision; then again they are stouter and beset on the under side with black bristles. The fore tibiz, which are comparatively stout, bear on the front side, not far from the basis, a stout black thorn, their tip is elongated into a coarse! tooth and their under side, which is beset with black bristles, has somewhat before this tooth a small excision; middle tibia long and rather slender ; their first half has only three short bristles; the second is fringed on the front side with a row of short black bristles ; upon the posterior side somewhat beyond the 904 DIPTERA OF NORTH AMERICA. | PART II. middle, there are a few long black bristles, and between these and the tip of the tibia, some long, curly black hairs. The hind tibie are much stronger than the middle tibia, their first half is stouter than the second and the front side before the tip is armed with a strong black bristle. Tarsi plain, their joints of decreasing length, the first joint of the middle tarsi with a few bristles. Halteres brownish-black. Wings blackish, all their veins broadly margined with black ; the margins of the costa and of the first four longitu- dinal veins are entirely confluent, so that the anterior part of the wings appears altogether black ; upon the middle of the posterior transverse vein and upon the curve of the last segment of the fourth longitudinal vein there is a black spot; the costal cell is of a dark brown color. Female. The only female which I possess, is not as well pre- served as the described male, especially the characters of the face cannot be recognized with certainty ; I would therefore recall the circumstance, that the face of most of the females of Scellus is less yellow than in the males. The first joint of the antennz in the female is considerably shorter than that of the male. Fore femora and fore tibie less stout, though the tip of the latter has also a dentiform, but less stout elongation; their under side has no excision before this tooth and the front side of the tibize no thorn. Middle femora not curved, on the larger half of their under side with a few sparse bristles. Middle tibisx plain, upon the first half with a considerable number of black bristles, upon the latter part of the posterior side without the curly hairs which are found in the male. Hind femora plain, slender, towards the tip but very little stronger, upon the second part of the under side with about six rather strong black bristles. Hind tibiz without the strong bristle which, in the males, exists at the tip of the front side. - Hab. Middle States. (Osten-Sacken); Illinois. (Le Baron.) 2. §. spimimanus Zert. % and 9.—Thoracis dorso obscure eneo, albido-pollinoso, opaco, abdomine ex viridi cupreo, nitido, halteribus subfuscis, alis nigris, basi et coste dimidie limbo subalbidis, margine postico toto cinereo, lamellis analibus maris albis, basim versus infra nigro-marginatis, apicem versus flavis, im summo apice puncto fusco notatis. The upper side of the thorax dusky bronze-colored, with whitish dust; SCELLUS. 205 abdomen coppery-green, bright ; halteres brownish ; wings black, though the root and the margin of half the costa is whitish, the whole posterior margin gray; anal appendages of the male white, towards the basis on the under side with a black margin, towards the tip yellow, at the ex- treme tip marked with a brown spot. Long. corp. 0.15. Long. al. 0.19. Syn. Hydrophorus notatus ZevtERsTEDT, Ins. Lapp. 701, 4, in obs. Hydrophorus spinimanus ZETTERSTEDT, Dipt. Scand. II, 445, 5. Male. Blackish bronze-colored. The face is comparatively a little broader than in S. exustus, covered with bright ochre-yellow dust and opaque. Antenne black. Front with whitish dust. The ground-color of the thorax is of a coppery-bronze ; upon the middle of the upper side more of a blackish-bronze, but almost everywhere so thickly covered with dust that the coppery lustre is only very little perceptible ; the dust on the upper side of the thorax is snow-white, upon the two longitudinal stripes near the lateral margin it is less thick, so that the coppery reflection of the ground-color is more distinct ; upon the middle there are two nar- row, dark longitudinal lines, close to each other, which do not reach as far as the posterior margin of the thorax. Upon the pleurse the color of the dust is more yellowish. The scutellum has two bristles, is rather opaque, with a thin whitish dust. Abdo- men green, mostly with a coppery lustre, which becomes much more bright near the lateral margin. The anal appendages are of middling length, white, near the basis on the lower margin with a narrow black border, and on the upper margin usually marked with a blackish spot; beyond the middle they are inflected up- wards and gradually assume a yellow color; their extreme tip is marked with a small brown spot and bears a small tuft of delicate pale hairs, which are turned backwards; about the middle of the interior margin there is a similar pubescence; between them, towards the anal region, there is a small tuft of delicate whitish hairs. Coxe bronze-black ; the four anterior with yellow and the two hind ones with a rather whitish dust ; the fore coxe with very short and delicate pale hairs, near and upon the tip with a few black bristles. Feet black, femora and tibie more black-green, the former bright coppery. Fore femora short, towards the basis very much thickened, beset on the under side with bristles of dif- ferent length, on the front side with a row of stiff black bristles. Middle femora long, stronger than in S. exustus and more curved, on the latter half of the under side with erect black bristles. Hind 206 DIPTERA OF NORTH AMERICA. [PART II. femora of a plain structure, not stouter than the middle femora; their under side has only close before the tip, a few black bristles. ‘The comparatively stout fore tibiz have on their front side, not far from their basis, a stout black thorn ; their tip is elongated into a very stout tooth, before which the under side of the tibiee, which is beset with strong bristles, has a small excision. Middle tibiee not quite so long and slender as those of S. exustus, on the upper side only with three or four short bristles, on the under side with a row of extremely long, straight, erect black bristles, and on the hind side with long curved hairs, which latter are more dense near the tip and curl up to the shape of a lock of hair. Hind tibie plain, scarcely stouter than the middle tibiz ; on their upper side, not far from the basis, there is a strong bristle, and on the latter half a few small bristles; the under side is beset with short smal bristlés, which are isolated upon the first part and closer together. and in more regular order upon the second-half; at the end of the under side there is a considerable number of less strong and less short bristles, of which the last is distinguished by its greater length; on the outside of the tip of the tibie there are several short and one longer and curved bristle, which has almost the thickness of a thorn. ‘Tarst plain, the joints of decreasing length, the first joint of the fore and of the middle tarsi with more, that of the hind tarsi with less bristles. Halteres yellowish-brown, the lower part of the knob more dark. The wings of uniform breadth aud at the end more rounded than in the other species; an un- commonly large black spot covers their apical half with the excep- tion of a broad gray border on the posterior margin, and extends as a broad cloud along the fifth longitudinal vein almost as far as the anal cell; inside of the discoidal cell it is somewhat paler, otherwise, however, so dark that the two black spots, peculiar to this genus, upon the posterior transverse vein and upon the last segment of the fourth longitudinal vein, can only be perceived when the wing is held towards the light; the anterior part of the wing from the basis as far as the middle is dingy-whitish hyaline ; the anal angle and a broad border along the posterior margin are more hyaline-gray. Hab. Fort Resolution, Hudson’s Bay Territory. (Kennicott.) Female. It is distinguished from the male by the following characters: Face with pale yellow-grayish, front with brown dust. The middle of the upper side of the thorax with yellow-brownish SCELLUS. 207 dust, marked with a few spots of whitish dust. Its lateral stripes are covered with brown, the edge of the lateral margin, however, again with gray-whitish dust. The abdomen is more green, less coppery and less bright than in the male. The dust upon the pleurze and upon the fore coxe is less yellow. The fore femora are of a similar structure as those of the male ; the fore tibize with- out a thorn on the inside, elongated at the tip ina much smaller and sharper tooth, before which there is no excision; otherwise the feet are plain, the middle and hind femora straight and much more slender than in the male ; middle and hind tibie only sparely beset with scattered bristles. , Observation.—As I do not possess a North American female of S. spinipes, I have prepared the above description from Swedish specimens. 3. S.avidus, nov. sp. %.—Thoracis dorso eneo-nigro, nitido, mar- gine et linea media cinereo-pollinosis, pleurarum plag& supera, abdo- mineque ex viridi lete cupreis, nitidissimis, halteribus albis, alis cine- reis, punctis duobus nigris, altero in vend transversa posteriore, altero in ultimo vene longitudinalis quartz segmento; lamellis analibus maris albis, basi et apice tamen nigris. Upper side of the thorax bronze-black, shining, its margin and a middle line dusted with gray powder; a large spot on the upper part of the pleure and the abdomen bright greenish copper-colored, very shining ; halteres white; wings gray with two large dots, one on the posterior transverse vein, the other upon the last segment of the fourth longitu- dinal vein; the anal appendages of the male are white, but their basis and tip are black. Lowig. corp. 0.17. Long. al. 0.21. Male. Face somewhat broader than in the previous two spe- cies, dusted with bright ochre-yellow powder, opaque. Front with white dust. Antenne black. Most of the upper side of the thorax bright bronze-black with faint violet reflections; its whole margin has a rather broad border dusted with a whitish-gray pow- der, and therefore opaque; there is also a narrow middle line, which is ‘much abbreviated behind and likewise dusted with a white-grayish powder. The upper part of the pleure, from the shoulder to the root of the wings, is entirely without dust, metallic greenish copper-colored, very much shining ; as I have only a sin- ale specimen, I am unable to judge with certainty whether this large shining spot is also present in fresh specimens, as I believe it to be, or whether in the above described specimen it is merely ° 208 DIPTERA OF NORTH AMERICA. [PART II. rubbed off; the other parts of the pleure are dusted with gray. The scutellum, which has two bristles, is greenish bronze-colored and opaque. The very shining abdomen is of a bright coppery color, but assumes, when its surface is looked upon in a very ob- lique direction, a green or at least brassy-yellow color. The tape- like anal appendages are very long, somewhat blackened at the basis, and still more so at the tip which is turned upwards, and there beset with a small tuft of blackish hair directed backwards; otherwise their margins are not hairy, although there is a single black bristle where the blackening of the tip begins on the under side in the vicinity of its inner margin. Near the anus between the above mentioned two appendages there are a few small black hairs. Coxee greenish-black, with white-yellowish dust; the fore- most have besides some pale hairs, almost imperceptible on account of their shortness and delicacy, a few black bristles before and upon the tip. Feet black with a metallic-green reflection, which gra- dually disappears upon the last joints of the tarsi. Fore femora towards their root not so much thickened as in the two preceding species, beset with strong black bristles of different length on the under side, on the front side with a sparse row of short black bris- tles. Middle and hind femora long, slender, straight, of a plain structure, beset on the second half with a moderate number of short, scattered black bristles. ‘The moderately stout fore tibize bear on their anterior side, not far from the basis, a short black thorn and are prolonged at their tip into a large, somewhat clumsy but sharp tooth, before which the under side of the tibia, provided with bristles, has a very small excision. The middle tibiz are long and slender; on the upper side they are beset with only three, on the anterior side with about seven scattered bristles of very moderate length; on the other half of their hind side they bear long curly black hairs. Hind tibize slender, straight, rather long, only on the second half with a few isolated black bristles; the bristles on the outside of their tip are also only short. Tarsi plain, their joints of decreasing length; the first joint of the fore and middle tarsi on the under side with numerous black bristles, the first joint of the hind tarsi only with a few and much shorter bristles. Wings hyaline-gray, somewhat darker towards the tip on account of the gray margin of the second, third and fourth longitudinal veins; upon the posterior transverse vein and upon SCELLUS. 209 the middle of the last segment of the fourth longitudinal vein there is a gray-blackish spot of considerable size. Hab. Fort Resolution, Hudson’s Bay Territory. (Kennicott.) A. 8. filifer, nov. sp. 4.—Thoracis dorso cinereo, opaco, abdomine cupreo, cinereo-pollinoso, subopaco, halteribus albidis, alis hyalinis in basi subalbidis, apicem versus cinereo-striatis punctisque duobus ma- jusculis nigricantibus, altero didymo in vena transversa posteriore, altero simplici in ultimo vene longitudinalis quarte segmento ; lamellis analibus maris angustissimis albis, in basi nigris, in summo apice fla- vicantibus. Upper side of the thorax gray, opaque ; abdomen copper-colored with gray- ish dust, rather opaque; halteres whitish; wings hyaline, whitish near the root, with gray stripes towards the tip; upon the posterior transverse vein with a double blackish spot of considerable size, and with a simi- lar, but single spot upon the last segment of the fourth longitudinal vein ; the anal appendages of the male are very narrow, white, black at the basis and yellowish at the extreme tip. Long. corp. 0.15. Long. al. 0.20. The narrow face is ochre-yellow. Antenne black. Front with white dust. Thorax blackish bronze-colored with copper-colored reflections; on the upper side with thick whitish dust, which almost conceals the ground-color, opaque; upon the pleure with a somewhat thinner dust of the same color. Upon the middle of the upper side there are two narrow parallel lines of a darker color, which do not reach as far as the posterior margin of the thorax. The scutellum, which has two bristles, is, of the same color as the pleure. The ground-color of the abdomen is like that of the thorax, is, however, more distinct, not being so thickly covered with dust; towards the lateral margin of the abdomen, where the dust almost entirely disappears, there is a bright cop- per-colored lustre. The anal appendages of the male, which are turned upwards at their tip, are not ribbon-like, as in the pre- viously described three species, but filiform, white, black at the root, at the tip pale-yellowish to a small extent; on the middle of their exterior margin there is a dense beard of delicate little white. hairs ; there is no tuft of hairs at their tip. Between them, in the anal region, only a moderate number of short delicate little hairs, which may be easily overlooked, are inserted. Coxe of a black- ish-bronze color with whitish dust; the fore coxe have, besides 14 210 DIPTERA OF NORTH AMERICA. [PART IL the pale, and, on account of its shortness and delicacy, almost im- perceptible pubescence, quite a number of black bristles. Feet black, the femora with a more coppery, the tibie with a more metallic-greenish tinge. Fore femora rather strongly thickened towards the basis, on the under side with strong black bristles of different length, on the front side only with an imperfect: row of short black bristles. Middle femora moderately thickened and strongly curved, on the under side of the basis with two or three not very long, on the apical half with a large number of long, straight and erect bristle-like black hairs. Hind femora plain, of middling stoutness, on the under side with bristle-like short hairs; on the upper side with two longer black bristles, of which the larger is not far from its tip. Fore tibia strong, with a large and sharp thorn on the front side, not far from the basis ; elongated at the tip into a large clumsy tooth; the under side of the tibia, pro- vided with bristles, has no distinct excision before this tooth. Middle tibie long, straight, a little stronger in the neighborhood of the basis; the first two thirds of their under and posterior side are fringed with long curly black hairs, the end of the under and front side, however, with long and stiff black bristles; on the under side, where these bristles. begin, there is between them a somewhat curved black thorn. Hind tibie straight, on the under side with short but very strong black bristles, one of which, being not far from the tip, is remarkable for its greater length; on the outside of the tip of the tibiz afew shorter and one somewhat longer curved bristle are inserted. Tarsi plain, their joints of decreasing length; the first joint of the fore and middle tarsi on the under side with black bristles, which are of considerable length near the basis of the tarsi, but decrease in length very rapidly so as to be very short on the larger portion of the joint; the under side of the first joint of the hind tarsi is everywhere beset with short black bristles. Halteres pale-yellowish, but the basis of the knob some- what brownish. Wings hyaline; almost the whole basal third appears somewhat whitish when seen in a certain direction; gray- ish stripes along the second half of the second and third longitu- dinal veins, likewise along the tip of the last segment of the fourth and the greater portion of the fifth longitudinal vein; there is also a gray streak between the third and fourth longitudinal veins ; upon the posterior transverse vein there is a blackish-gray double spot, and upon the middle of the last segment of the fourth longi- HYDROPHORUS. oe tudinal vein there is a larger rounded blackish-gray spot, which is less sharply defined on the side turned towards the tip of the wing. Hab. Fort Resolution, Hudson’s Bay Territory. (Kennicott.) Gen. XXXVI. HYDROPHORUS. Characters. The first joint of the antennz short, bare; the second very short; the third rounded, more or less distinctly notched under its tip; arista dorsal, two-jointed, apparently bare. Front a little excavated on the vertex, narrower anteriorly. Eyes large, higher than broad, encased below in the cheeks, which in their structure resemble those of Orthochile, and are broader than in the other genera. The face reaches somewhat below the lower corner of the eyes ; it is scarcely narrower in the male than in the female, its two upper thirds are usually a little concave ; the lowest third is separated from the upper one by two knotlike elevations near the eyes, is convex and ends in a sharp rounded edge. Pro- boscis of moderate thickness; palpi incumbent, in both sexes rather small. Upper side of the thorax only with moderately long hairs upon its, middle. Scutellum rather flat, though some- what elevated along its middle line, in all species known to me with four bristles. Abdomen broad and rather flat, very short, without bristles ; it has five segments in both sexes. The hypopy- -gium of the male is small and imbedded; at its lower end there are two small, dark-colored lamelle, obliquely turned down, and so closely approximated that they seem to form but one clumsy dentiform protuberance; usually no other appendages are seen besides these. Feet generally bare; middle and hind feet much longer and more slender than the fore feet ; fore femora gradually rather thickened towards the root; on their under side, either in both sexes or at least in the male, with short, thornlike bristles ; sometimes they are beset with a few longer and thornlike bristles ; fore tibize on the under side densely beset with very short thorn- like bristles ; middle tibiz never beset with longer hairs, even in the male ; tarsi plain, their joints very much decreasing in length; the empodium very distinct. Wings iong and narrow; the pos- terior transverse vein close to the margin of the wing; the third and fourth longitudinal veins usually somewhat Gaeereins towards their ends; in some species they are parallel; the sixth longitudi- nal vein usually apparent as far as the middle of its course. 212 DIPTERA OF NORTH AMERICA. [ PART II. Hydrophorus differs from Scellus by the fore femora and fore tibixe not being provided on the under side with long thorns, catching between each other, by the tip of the fore tibiee not being elongated into a clumsy projection, by the middle tibize of the male not being adorned with long hair, by the hypopygium not having those peculiar pale-colored appendages, which distinguish the | species of Scellus, &c. Liancalus has no notehes on the third joint of the antenne, its fore femora are not thickened and un- armed, and it has bristles before the incisures of the abdomen, so that no mistake can occur between the species of Hydrophorus and Liancalus. The name of Hydrophorus (from déep, water, and gépew, to carry) has been bestowed upon these inseets with reference to the ability of many of the species to run even upon agitated waters. The species of Hydrophorus known to me are distributed over Europe, Northern Asia, Africa and North America. There is no perceptible habitual difference between the species from the dif- ferent parts of the globe. Table for the determination of the Species. Face with white dust, shining green above. 1 innotatus, nov. sp. Face with brownish-yellow dust, opaque above. 2 eae and fourth longitudinal veins convergent. 2 pirata Lw Third and fourth longitudinal veins parallel. 3 parvus Lw. Description of the Species. 1. H. imnotatus, nov. sp. % and 9.—Olivaceo-eneus, scutello virescente, abdomine viridi, femoribus tibiisque viridibus, tarsis nigris, facie supra viridi-splendente, polline pleurarum albido, venis alarum cinerascentium atris, longitudinalibus tertia et quarta apicem versus paulo convergentibus. Metallic olive-brown with greenish scutellum and green abdomen ; femora and tibie green; tarsi black; face shining green above; pleure with whitish dust; wings gray with black veins ; the third and fourth longi- tudinal veins somewhat converging towards their end. Long. corp. 0.13. Long. al. 0.22. The dust upon the face is yellow-brownish immediately below the antenne ; otherwise everywhere white in the male, but so thin upon the entire upper part of the face that its metallic-green eolor becomes distinctly perceptible ; in the female the face is covered with white dust only along the sides, upon the middle with s HYDROPHORUS. 213 brownish dust. Antenne entirely black. Front greenish-black, opaque ; seem in an oblique direction the covering of brown dust upon it becomes perceptible, which otherwise is visible only on the anterior margin. The ground-color of the occiput is green and but little covered with brownish-gray dust. The cilia of the upper orbit are, as usual, black, the dense and hair-like cilia on the late- ral and inferior orbits, however, rusty-yellowish. The upper side of the thorax metallic olive-brown; the hindmost part with a metallic-green reflection; the dust upon itis brown. Scutellum with four bristles, shining, rather green, though somewhat copper- colored upon its middle. Pleure and coxe with whitish dust. Abdomen metallic-green, shining, especially on the sides; the short hair upon it is blackish, upon the sides of the first segment, however, fallow-yellowish. Fore coxe on their front side with a very short and delicate whitish pubescence, beset on the upper half of their exterior side with a moderate number of compara- tively long black bristles; a few of them are also at the tip. Femora slender, green, with an-almost imperceptible grayish dust; the fore femora as usual thickened towards their basis, and beset on the under side near the basis with four or five rather lony thornlike bristles; besides these there is, nearer to the anterior margin, an apparently incomplete row of very short bristle-like little hairs, which are but difficult to perceive. Tibize dark green, the foremost on their under side uniformly fringed with very short, black thornlike bristles. Tarsi black. Cilia of the tegule yel- low. Halteres with a dusky yellow peduncle and with blackened knob. Wings very long, tinged with gray, not darker towards the anterior margin and with veins. which are black up to the ex- treme root; the end of the third longitudinal vein is somewhat curved backwards so as to converge distinctly towards the fourth longitudinal vein; no dark spot is to be seen neither upon the fourth longitudinal vein, nor upon the convexity, crossed by the ~ last segment of the fourth longitudinal vein. Hab. Sitka. (Sahlberg.) Observation.—N otwithstanding the not unimportant difference. in the coloring of the dust on the lower part of the face between the two sexes described above, I have no doubt that both belong together. From the other North American species, known to me, H. innotatus differs by the shining green color of the upper part of the face. Among the European species it can only be 214 DIPTERA OF NORTH AMERICA. [ PART IL. compared to balticus Meig., alpinus Wahlb. and callostomus Lw. It can easily be distinguished from balticus by the dark knob of the halteres; from alpinus by the want of a curved thorn at the end of the fore tibie; from callostomus by its more con- siderable size and a comparatively narrower face. 2. H. pirata Lorw. 9.—Olivaceo-zneus, thorace et scutello cupreo- splendentibus, abdomine virescente, femoribus tibiisque viridibus, tarsis nigris, polline faciei opace ex fusco ochraceo, pleurarum polline albido, venis alarum cinerascentium nigris, longitudinalibus tertia et quart apicem versus paulo convergentibus. Metallic olive-brown, thorax and scutellum with a copper-colored reflex- ion; abdomen greenish; femora and tibie green; tarsi black; the dust upon the opaque face brownish ochre-yellow ; that of the pleure whitish ; wings gray with black veins, the third and fourth longitudinal veins somewhat converging towards their ends. Long. corp. 0.15. Long. al. 0.24—0.26. Syn. Hydrophorus pirata Lozrw, Neue Beitr. VIII, 71, 1. Face with brownish-yellow dust, entirely opaque. Palpi black and covered with black hairs, on the upper side with brownish- yellow dust. Antenne entirely black. Front brownish-black, opaque; when seen in an oblique direction, it seems as if partially covered with brownish-yellow dust. On the occiput the ground- color is green, however almost entirely covered with grayish- yellow dust, or rendered very opaque. The cilia of the upper orbit are, as usual, black, the dense and hair-like cilia of the lateral and inferior orbits however, yellow. The upper side of the thorax is metallic olive-brown with a copper-colored reflection ; the scarcely perceptible dust upon it is brownish-yellow. Scutel- lum with four bristles, shining, copper-colored upon the middle, on the margin green. Pleura and coxe with whitish dust. Ab- domen more green than the thorax and with a coppery tinge, upon ‘the greater portion of the last segment and upon the posterior margin of the preceding segments usually beautifully green; its short hair is blackish, only upon the posterior margin of the first and of the last segment it is pale. Fore coxe on their front side with a very short and delicate whitish pubescence, on their ex- terior margin fringed with black, stiff, but not very strong, bris- tles, of which there are also a few on the tip. Femora slender, green, and covered with thin, almost imperceptible, whitish dust ; HYDROPHORWS. pn the fore femora as usual, thickened towards the basis, on their under side with two rows of thorn-like bristles, the inner row of which reaches as far as their tip, while the ‘exterior one stops already on the middle of the femora. Tibiz dark-green, the fore- most uniformly fringed, upon their under side, with very short thorn-like bristles. Tarsi black. Cilia of the tegule fallowish- yellow. Halteres with a dusky-yellowish peduncle, and with blackened knob. Wings very long, tinged with gray, not darker towards the anterior margin, with black veins up to the extreme root; the end of the third longitudinal vein somewhat approaches the fourth, so that these veins converge distinctly towards their ends ; upon the posterior transverse vein and upon the convexity, which the last segment of the fourth longitudinal veins crosses, there is a somewhat more gray spot, which is almost invisible to the naked eye. Hab. Pennsylvania, District of Columbia. (Osten-Sacken.) Observation.—It is difficult to determine, whether H. pirata is not one of those four species of Hydrophorus which Mr. Walker has described as species of Medeterus. They agree in a good many respects not only among themselves, but also with H. pirata, while each of them exhibits also some distinguishing featuf#e. . viridiflos must be much more green, according to Mr. Walker’s statements, than H. pirata; besides, the cilia of the inferior orbit of the former one are white, while those of the latter are yellow; moreover, its abdomen is conical and longer than the thorax, an entirely uncommon character for a female of Hydrophorus, and making it almost doubtful whether it really belongs to this genus; finally the veins of the wings are said to be brownish-yellow near the root of the wing; these discrepancies are altogether too great to justify the supposition that A. pirata can be identical with viridiflos Walker. The face of Walker’s female of H. glaber is said to be covered with golden-yellow dust, the abdomen on the upper side clothed with brownish-yellow hairs, the femora rather stout and the halteres brownish-yellow. These differences are likewise too important to admit the identity of H. pirata with H. glaber. The face of Walker’s female of H. chrysologus is said to be also covered with golden-yellow dust; the wings are said to be brown along the anterior margin, and to measure only three lines in expanse, whereas they measure six lines in H. pirata. Under such circumstances the identity of these species is out of question. 216 DIEFTERA OF NORTH AMERICA. [ PART II In Walker’s description of H. alboflorens, the brownish-yellow color of the dust upon the face, the color of the halteres and the black color of the hair on the upper side of the abdomen, agree better with HZ. pirata; but it is added, that the thorax is covered with brownish-yellow dust, that the dust upon the femora is of the same color, and finally that the pulvilli are of a pale-yellowish color, of all which there is no trace in . pirata 3. H. parvus Lorw. %.—Olivaceo-eneus, thorace et scutello cupreo resplendentibus, abdomine obscure virescente, femoribus tibiisque viridi- . bus, tarsis nigris, polline faciei opace ex fusco ochraceo, pleurarum polline albido, venis alarum ex nigro cinerascentium nigris, longitudinalibus tertia et quarta perfecte parallelis. Metallic olive-brown, thorax and scutellum with a copper-colored re- flection; abdomen dark-green, femora and tibize green, tarsi black, the dust upon the entirely opaque face brownish ochre-yellow, that on the pleure whitish; the wings blackish-gray with black veins, the third and fourth longitudinal veins entirely parallel. Long. corp. 0.09—0.10. Long. al. 0.13. Syn. Hydrophorus parvus Loew, Berl. Entom. Zeitschr. VI, 214, 67. Res@mbles in the structure of the body H. pirata very much, but sufficiently distinct from it by its smaller size, a more blackish color of the wings and the complete parallel course of the third and fourth longitudinal veins. Face with brownish ochre-yellow dust, entirely opaque, very much narrower upwards. Palpi black, antennse also black. Front almost velvet-black, with yellow- brownish dust, which is not distinctly perceptible in every direc- tion. Ground-color of the occiput green, covered above with yellowish, below and on the lateral margin with whitish dust. Cilia of the upper orbit black, of the inferior one white. Upper side of the thorax metallic olive-brown with almost violet and coppery reflections, the latter of which form two indistinct longitu- dinal lines and are more extended near the posterior margin of the thorax. Scutellum shining copper-colored, with four bristles, the lateral bristles much shorter than those which are nearer to the tip. The abdomen is green, rather opaque, upon the middle somewhat coppery, on the lateral margin and on the under side distinctly covered with white dust ; the very short hair upon-it is black. Coxe, femora and tibie black-green. The fore coxx are fringed on their front side with very delicate whitish har ACHALCUS. 917 which, on account of its shortness, is difficult to perceive; on their exterior side some short white little hairs are also inserted ; one of the uppermost, however, is sometimes of a black color. The fore femora, which are moderately thickened towards the root, have, on their under side, a dense row of very short, straight, erect little bristles, and near the basis two or three longer bristles. The under side of the fore tibie is also provided with a dense row of very short small bristles. Tarsi black. The halteres appear to be black. Wings long, tinged with a gray-blackish color, not darker towards the anterior margin, and up to the ex- freme root with black veins; the end of the fourth longitudinal vein is completely parallel to the third; the posterior transverse vein is perpendicular, without dark margin and dark spot upon its middle; the convexity crossed by the last segment of the fourth longitudinal vein is not darker than its surroundings. Hab. Pennsylvania. Gen. XXXVIII. ACHALCUS. Characters. Color non-metallic. The first joint of the an- tenne glabrous, the third pointed-ovate; the long and slender arista subapical. Face narrow. Abdomen with six segments in both sexes; the female abdomen at the end without a coronet of bristles. Hypopygium small; its exterior appendages have the shape of small lamelle. The first joint of the hind tarsi without bristles, shorter than the second. ‘The sixth longitudinal vein of the wings is wanting. It is impossible to overlook the relationship of the genus Achalcus with the four following genera, which are distinguished by the posterior end of the thoracic dorsum being provided with a concave area. This relationship is also illustrated by the want of the coronet of bristles on the posterior end of the female abdomen, which Achalcus has in common with these four genera. I have only a few speci- mens of Achalcus flavicollis in my possession; the manner in which they are pinned renders it impossible to ascertain whether the posterior end of the upper side of the thorax has a concave surface or not ; it seems to me that the latter is the case. The name of the genus (from a, non, and yaaxos, brass) has refer- ence to the non-metallic color of the species. 218 DIPTERA OF NORTH AMERICA. [ PART II. The few species of Achalcus as yet known, belong all to the European fauna. Gen. XXXIX. MEDETERUS. Characters, Face of both sexes rather broad, and in both with a transverse swelling below its middle. The proboscis very much swollen; when in repose, both sides of its opening are so close together, that its lower surface forms but a single convexity. The first joint of the antenne glabrous, the third rounded or somewhat ovate, with a slender apical or subapical arista. Eyes not hairy. The upper side of the thorax on its posterior end with a concave declivity. The hypopygium with a short peduncle, entirely dis- engaged, inflected under the venter, with rather short appendages. ' Feet rather long and slender, almost entirely without bristles ; the first joint of the hind tarsi without bristles, shogter than the second. The third longitudinal vein, in most of these species, ends not far from the tip of the wing, and the last segment of the fourth longi- tudinal vein converges towards the third. | The genus consists of two groups; the first of hee differs from the second by the shorter distance of the posterior transverse vein from the margin of the wing, by a stronger convergency of the third and fourth longitudinal veins, by the smaller length of the first joint of the hind tarsi and a more slender structure of the body. The name of Medeterus (from pydérepos, neither of the two) was given to this genus, because its species could not be located in any of the two genera of Dolichopodide, established at that time. The known species belong to EKurope, Northern Asia, North- ern Africa, and North America. Of the latter I possess un- fortunately only fragments of specimens, so that my statements about them will necessarily be very imperfect. 1. M. migripes Lorw. 9.—Nigricans, antennis pedibusque concolori- bus, thoracis dimidio anteriore albido-bivittato, dimidio posteriore et scutello albido-pollinosis, alis subhyalinis. Blackish, antennze and feet of the same color, the anterior part of the thorax with two whitish stripes, the posterior half and the scuteilum covered with whitish dust, wings rather hyaline. Long. corp. 0.12. Long. al. 0.12. Syv. Medeterus nigripes Lozw, Neue Beitr. VIII, 73, 1. MEDETERUS. 219 Blackish, without metallic lustre. Face opaque from brown dust; its ground-color seems to be greenish-black, below the trans- verse swelling, above it of a purer black. Palpi and proboscis shining black. Antenne black. Front opaque from brown dust. The cilia of the inferior orbit pale. The anterior half of the upper side of the thorax is brown with dust and has two distinct, yellow- ish-white longitudinal stripes, which reach from the anterior mar- gin as far as the impression upon the posterior half; this impres- sion and the scutellum are covered with grayish-white dust. The upper part of the pleurz is covered with brownish-gray dust; the bristles above the fore cox are black. Abdomen black without any distinct trace of dust. Coxe and feet black; fore coxse very glabrous, only with a few black bristles near the tip; the extreme tip of the knees dark pitch-brown (which might be easily over- looked). The second joint of the hind tarsi is three times the length of the first one. Cilia of the tegule whitish. Halteres whitish with a darker peduncle. Wings hyaline, scarcely a little tinged with gray, with dark-brown veins; the posterior transverse vein distant from the margin of the wing somewhat more than its own length ; the third longitudinal vein ends close before the tip of the wing; the last segment of the fourth longitudinal vein is uncom- monly straight and its end lies close to the end of the third longi- tudinal vein. Hab. Middle States. (Osten-Sacken.) 2. MI. weles Lorw. 4.—WNigricans, antennis concoloribus, facie opaca, pedibus testaceis, femorum dimidio basali ex nigro piceo, alis subhyalinis, maris hypopygio atro, nitido, ovato, subsessili. Blackish, antenne of the same color; face opaque; feet yellowish, basal half of the femora brownish-black; wings rather hyaline, hypopygium black, ovate, almost sessile. Long. corp. 0.11. Long. al. 0.11. Syn. Medeterus veles Lonw, Neue Beitr. VIII, 73, 2. Blackish, without metallic lustre. Face opaque from brownish- eray dust; its ground-color is black, more distinet upon the part below the transverse swelling, the dust there having been rubbed off. Palpi and proboscis black, shining. Antenne black. Front opaque from brown-gray dust. The upper side of the thorax is marked in a similar manner as in the preceding species, but the dust on the anterior half is more gray and that on the posterior half and on the scutellum, at least in the described specimen, less 220 DIPTERA OF NORTH AMERICA. [ PART ILI. striking. The upper part of the pleure is covered with gray dust and the bristles above the fore cox are of a pale color. The abdomen is less thickly dusted than the thorax, appears however rather gray in some directions on account of its cover of dust. The peduncle of the hypopygium is so short as to appear ses- sile; it is rather stout, ovate, almost reversed-pyriform, black, polished on its entire right side and on the latter half of the left side. Coxe black. Feet brownish-yellow, all femora, from the root as far as the middle, pitch-black, this color vanishing gradu- ally. Cilia of the tegule whitish ; halteres whitish with a darker peduncle. Wings hyaline, scarcely tinged with a little gray, veins brownish; the posterior transverse vein distant from the margin of the wing more than its own length. ‘The third longi- tudinal vein ends a little farther from the tip of the wing than in the preceding species; the last segment of the fourth longi- tudinal vein is also very straight, converges, however, less towards the third longitudinal vein than in IL. nigripes. Hab. Florida. (Osten-Sacken. ) Observation. I have received from Mr. Le Baron two females, captured in Illinois. They are somewhat larger than the above described male, and the lower part of the face is greenish-blue, but very little shining. Otherwise they agree with it perfectly. The different color of the lower part of the face would be a sufficient specific distinction, if the bad condition of the above described male of M. veles did not admit the supposition that the difference in its color is an unnatural one. I prefer therefore not to consider these females as belonging to a different species. Gen. XL. CHRYSOTIMUS. Characters. Size of the body small. Antenne small; their first joint glabrous; the third joint very short, usually broader than long, distinctly hairy, with an apical or almost apical arista. Eyes with a very short pubescence. The posterior end of the thorax with a rather large, distinctly concave, sloping area. The bristles upon thorax and secutellum yellow. Abdomen in all the species partially yellow. Feet not elongated; the first joint of the hind tarsi without bristles. Posterior transverse vein upon, or more or less before, the middle of the wing; the last seement of the fourth longitudinal vein neither broken nor distinctly bent CHRYSOTIMUS. 221 forward, parallel to the third vein and ending into, or somewhat beyond, the tip of the wing. Hypopygium small and imbedded. The species of Chrysoltimus were formerly united with the species of Chrysotus. The principal difference between these genera consists in the structure of the thoracic dorsum. Chry- sotus has immediately before the scutellum a small, more or less distinct, transverse swelling, which is separated from the rest of the surface by a rounded impression, and the convexity of the thorax begins here. In Chrysotimus this transverse swelling is entirely wanting, and the thorax shows in the middle of its hind- most part a rather conspicuous, distinctly concave surface, ‘slop- ing towards its posterior margin. Moreover in Chrysotimus the feet are much less hairy, the wings comparatively a little larger, the appendages of the hypopygium more concealed, the integu- ments of the whole body softer, the bristles upon thorax and scu- tellum not black, but yellow, and the abdomen always, at least partially, of a yellow color, which is not the case with any of the genuine species of Chrysotus. The name of the genus (from ypvoos gold, and r.wy, honor) re- minds us of the coloring of the species, as well as of their former connection with the genus Chrysotus. | Besides the two North American species, described below, only European species are known. 1. C. pusio Lorw. °.—Lete viridis, abdominis flavi segmento ultimo viridi, antennis palpisque nigris. Bright green; abdomen yellow, the last segment green; antenne and palpi black. Long. corp. 0.07. Long. al. 0.09. Syy. Chrysotimus pusio Loew, Neue Beitr. VIII, 74, 1. Face dark-green with a thin white-grayish dust. Palpi brown- ish-black, appearing rather pale on account of a white-grayish dust. Antenne entirely black ; front shining metallic-green ; the frontal bristles black, in another direction fallow-brownish, with a yellow lustre. The cilia of the whole orbit yellowish. Thorax and scutellum pale metallic-green, with whitish dust, but shining and fringed with yellow bristles. Metathorax and pleure of the same pale-green color, the latter with thick whitish dust. Abdo- men uniformly yellow, only on the upper side of the last segment ereen. All the coxe and feet yellow, only the last joint of the 222 DIPTERA OF NORTH AMERICA. [PART IL. tarsi brownish-black ; all the hairs, as well as the few short bristles upon them, are yellowish, though the latter appear dark when held towards the light. Halteres and tegulee yellowish, the latter with yellowish cilia. Wings hyaline with a yellow-grayish tinge and yellow veins; the short and steep posterior transverse vein lies more closely to the axillary incision than to the tip of the wing ; its anterior end is not quite so far distant from the extreme basis of the costa as from the tip of the wing. Hab. New York. 2. C. delicatus Lorw. $.—Lete viridis, abdominis segmentis se- cundo et tertio flavis, antennis nigris, palpis flavis. Bright green, the second and third abdominal segments yellow, antennz black; palpi yellow. Long. corp. 0.08. Long. al. 0.10. Syn. Chrysotimus delicatus Lozw, Neue Beitr. VIII, 74, 2. Face blackish-green, covered with white-grayish, not very strik- ing, dust. Palpi pale-yellowish. Antenne black. Front metal- lic-green, indistinctly covered with whitish dust; frontal bristles black, in another direction fallow-brownish with yellow lustre. The cilia of the orbit seem to be altogether yellow. Thorax and scutellum pale metallic-green, with gray-whitish dust, but shining and fringed with yellow bristles. The metathorax and the pleure have a similar, but more dull, coloring; the latter are covered with white-grayish dust. The first and the two last ab- dominal segments are green and shining, the second and third, in fresh specimens, are undoubtedly of a yellow color; in the only specimen, which I possess, both are infuscated to a considerable extent at their basis; upon the posterior corners they show a dusky-whitish color. The color of the venter cannot be distinctly perceived, but it seems to correspond with that of the upper side. Coxe and feet yellow, only the last joint of the tarsi brownish- black. All their hairs, as also their bristles, are yellowish, though the latter appear to be dark when held towards the light. Hal- teres and tegule yellowish, the latter with yellowish cilia. Wings hyaline, tinged with grayish; towards the anterior margin with a yellow-grayish tinge; the veins on the posterior part are more yel- low-brownish, on the anterior part more yellow; the short poste- rior transverse vein has not such a steep position as in the pre- XANTIOCHLORUS. 293 ceding species, and isa little more distant from the tip of the wing. Hab. New York. Gen. XLI. KANTHOCHLORUS. Characters. Color of the body non-metallic, yellow, often with green spots. Antenne very short; their first joint remarkably short and without hairs, the second transverse, the third very short ; the arista, which is distinctly clothed with hairs, is inserted upon the back of the third joint, in the vicinity of the basis. The thorax has upon its posterior half an impressed area, which is sloping downwards. The last segment of the fourth longitudinal vein is but very gently inflected, and converges somewhat towards the third longitudinal vein ; the sixth longitudinal vein disappears already far before the margin of the wing. Feet rather long; hind tarsi much shorter than the hind tibie ; their first joint with- out bristles and shorter than the second. Abdomen of the male not elongated; the hypopygium rather swollen, not imbedded, pointing straight backwards, so that the abdomen thereby appears to be somewhat elongated; the appendages are small, but dis- tinctly visible. The abdomen of the female obtuse at the tip, somewhat impressed below, and without a coronet of bristles. In consequence of the color of the body, the species of Xantho- chlorus might perhaps be mistaken for species of the genera Chry- sotimus and Saucropus. In Chrysotimus the position of the arista is more subapical; the third and fourth longitudinal veins are parallel, the feet shorter, and the hind tarsi almost as long as the hind tibiz, the hypopygium of the male is smaller and imbedded, and the last segment of the female abdomen protrudes in the form of a short ovipositor. Of all this, nothing is to be found in Xan- thochlorus. In Saucropus the abdomen is elongated, the hypopy- gium inflected under the abdomen and the last abdominal segment of the female is a sort of an ovipositor; all this is not to be found in Xanthochlorus ; the feet of the species of Saucropus are also much more elongated than those of the species of Xanthochlorus. The name of this genus (from farS0s, yellow, and yawpds, green) has reference to the peculiar color of the species. Besides a few European species, only the following North 224 DIPTERA OF NORTH AMERICA. [PART II. American species is known, which may perhaps be identical with one of the European species. 1. X. helvinus Lorw. 9.—Flavus, fronte, facie et setis thoracis nigricantibus. | Yellow, front, face and the bristles of the thorax blackish. Long. corp. 0.11. Long. al. 0.13. Syn. Xanthochlorus helvinus Lozw, Neue Beitr. VII, 75, 1. Altogether yellow. Front and face blackish with whitish dust, which is more distinctly visible in an oblique direction. The arista, the bristles on the vertex and on the upper side of the thorax, black, but shifting into brown in a reflected light. A small blackish spot on the pleura, immediately below the root of the wing. Hab. Chicago. Observation.—This species resembles the European X. tenellus Wied., very much, and is probably a slight variety of it. No plastic distinctions at all are to be seen; the only difference which I can perceive, is the darker color of the bristles upon the vertex and on the upper side of the thorax. The comparison of the male is necessary in order to determine whether this species can be con- sidered as a variety of X. tenellus. Gen. XLII. SAUCROPUS. The species of this genus, which older authors have united with Porphyrops, agree in many characters so much, and differ by these characters so sharply from the related species of the Doli- chopodide, that their claim to form a separate genus cannot be questioned. The following are the principal characters of this genus: First joint of the antenn without hair on the upper side ; arista dorsal. The thorax with a sloping area upén the mid- dle of its posterior end. Feet very long and slender; hind tibiz elongated ; the first joint of the hind tarsi without bristles, shorter than the second. Abdomen elongated and narrow; especially in the male. Hypopygium disengaged, short and stout, inflected, with short, very little developed appendages. Color of the body principally, or at least partially, yellow. Hairs and bristles chiefly black. or SAUCROPUS. 22 The characters by which the genus Saucropus is distinguished from the related genera, need not be repeated here, as they have already been sufficiently explained among the characters of those genera. The name:-of Saucropus (from cavxpos, delicate, and mows, foot) has reference to the great slenderness of the feet, which distin- guishes all the species of this genus. The known species are distributed over Europe, America, and South Africa. The American species resemble more those of Europe than those of South Africa; in the latter the third and fourth longitudinal veins are parallel, while in the European species the last segment of the fourth longitudinal vein approackes the third longitudinal vein, although very gradually, still, in gene- ral, very strongly. 1. S. dimidiatus Lorw. 4 .—Pallide flavus, thoracis lined media et macula posticda nigris, abdomine nigrofasciato, setis coxarum anteriorum albidis. Pale-yellow, thorax with a black middle line and with a black spot upon the posterior end, abdomen with black bands; the anterior coxe with whitish bristles. Long. corp. 0.18. Long. al. 0.17. Syy. Saucropus dimidiatus Loew, Neue Beitr. VIII, 75, 1. Pale-yellowish. Face very narrow, white. Antenne bright- yellow. Front black with white dust; frontal bristles black. Cilia on the posterior orbit as well as the two stronger bristles behind the upper corners of the eyes, yellow-whitish. Upper side of the thorax reddish-yellow; the middle line and the sloping area on its posterior margin are black. Scutellum whitish-yellow with two strong black bristles; on the outside of each of these bristles there is a very small delicate hair, easily overlooked, which in all our European species is much stronger. Metathorax black ; the pleure have a small black dot above the middle coxe. Abdo- men with three black transverse bands, the first in the vicinity of the basis of the second segment, the two following near the basis - of the third and fourth segments; the two last are somewhat emarginated on the middle of their posterior margin. Hypopy- gium short and clumsy, shining black; its small exterior appen- dages are white. Coxe and feet pale-yellowish; on the fore and middle cox there are altogether no black, but only whitish bris- 15 996 DIPTERA OF NORTH AMERICA. [PART 10, tles ; the hairs on the front side of the fore coxee are also whitish ; on the outside of the hind coxe there is a solitary black bristle. Tibize and tarsi elongated and very slender; middle and hind tarsi strongly infuscated from the tip of the first joint; the fore tarsi from the tip of the first joint become likewise more dark, though their color changes much more gradually into brown. Cilia of the tegule whitish. Wings hyaline with a slight gray-yellowish tinge ; the end of the fourth longitudinal vein approaches rather strongly the end of the third. ! Hab. Florida, District of Columbia. (Osten-Sacken.) 2. 8. rubehius Loew. 9.—Pallide flavus, thoracis macula postica, abdominis fasciis setisque coxarum nigris. Pale-yellow ; thorax with a black spot upon the posterior side; abdomen with black bands; coxe with black bristles. Long. corp. 0.25. Long. al. 0.23. Syn. Saucropus rubellus Loew, Neue Beitr. VIII, 76, 2. Pale-yellowish. Face narrow, white. Antenne bright-yellow. Front black with white-yellowish dust. The frontal bristles and the two stronger bristles behind the upper corners of the eyes, black. Cilia of the orbit yellowish-white. Upper side of the thorax reddish-yellow, the sloping area on its hind margin black. Scutellum yellowish with two strong black bristles ; on the outside of each there is a very minute delicate hair, easily overlooked. Metathorax brown only on the upper margin and upon the mid- dle line. Pleursz with a black dot above the middle coxe. Ab- domen with four black transverse bands of uniform breadth, of which the first near the anterior margin of the second segment, the others on the anterior margins of the following segments; the last of these bands is sometimes indistinct. Coxee and.feet pale- yellowish. The bristles on the fore coxee black; the hair on the front side blackish, towards the basis of the coxe pale; middle cox with black bristles and hairs; the hind coxe on their out- side with a single black bristle. Tibia and tarsi elongated, very slender; the tarsi from the tip of the first joint infuscated. The cilia of the tegule yellowish. Wings with a very distinct gray- yellow tinge; the end of the fourth longitudinal vein rather strongly | approaches the end of the third one. Hab. Virginia. (Osten-Sacken. ) SAUCROPUS. O27 3. S. superbiems Lorw. % and 9.—Ex glauco viridis, abdomine lete eneo-viridi, basim versus flavo. Grayish-green, the abdomen shining metailic-green, towards the basis yellow. Long. corp. 0.13—0.14. Long. al. 0.15. Syn. Saucropus superbiens Lorw, Neue Beitr. VIII, 76, 3. Face of the male entirely linear; that of the female also very narrow, snow-white. Palpi and proboscis dark-yellow. Antenne bright reddish-yellow ; the small third joint somewhat infuscated at the tip. Front with thick whitish dust; the frontal bristles black. The cilia of the upper orbit black, those of the lateral and inferior orbits whitish. The upper side of the thorax has a pale, metallic-green ground-color, more copper-colored towards the sides, appears, however, on account of the thick gray-whitish dust, opaque and glaucous. Scutellum more blue-green, but also rather thickly covered with gray-whitish dust; it has two strong black bristles. The pleura, which are covered with thick white dust, have a grayish-green ground-color, only their posterior mar- gin (epimera metathoracis) is of a yellow color. Abdomen some- what less elongated than in the preceding species; its first seg- ment yellow, usually with a blackish spot on each side, which expands more in some specimens, so that the greater portion of this segment is of a blackish color; the second segment is also yellow, has however on each side a large, bright, metallic-green spot, which reaches from the posterior almost to the anterior mar- gin and not unfrequently comes in contact with the opposite spot and forms a complete band, so that the anterior margin of this segment alone remains yellow. The following segments are on their whole upper side of a very saturate metallic-green coloring and very shining; towards the lateral margin the eolor often changes more into gold-green, rarely into coppery. Venter yel- low. *The small rounded hypopygium of the male yellow. All the cox and the long slender feet pale-yellow ; the stronger hairs and bristles on the fore cox are fallowish-yellow in the males, black-brown in the females; the more delicate hairs are pale-yel- - lowish in both sexes. Tibize and tarsi very elongated, especially the fore and middle tarsi of the male, the first joint of which is almost as long as the tibize and considerably longer than the four following joints together; in the female, however, the fore and middle tarsi are less elongated, especially their first joint, though 928 DIPTERA OF NORTH AMERICA. [PART Ir they exceed the tibie in length not inconsiderably ; the hind tarsi are but a little longer than the tibie, their first joint not much longer than the second. The tibiz and tarsi of the hind feet are sparsely beset with very short bristles, which, in the female, dis- tinetly differ from the usual short hairs, in the male however scarcely exhibit any difference. The cilia of the whitish tegulz appear in some directions dark-brown, in others shift into yellow- ish. Wings hyaline, little tinged with grayish; the veins brown- ish ; the long last segment of the fourth longitudinal vein is gently inflected forward and ends rather closely near the end of the third longitudinal vein. Hab. Florida. (Osten-Sacken.) 4, S. temtlis, nov. sp. ©.—Dilute fiavescens, fronte, thoracis dorso preter limbos laterales scutelloque preter marginem ex cinereo vires- centibus, pleurarum dimidio superiore et metanoto ex glauco cinereis, fasciis basalibus segmentorum abdominalium nigris. Pale-yellowish, the front, the back of thé thorax, with the exception of the lateral margins, and the scutellum with the exception of its margin, gray-greenish ; the upper half of the pleure and the metathoraz green- ish-gray ; abdominal segments at the basis with black bands. Long. corp. 0.13. Long. al. 0.14. , Pale-yellowish; the face, very narrow for a female, and the palpi have the same color ; both are somewhat covered with whitish dust. Antennne pale-yellowish, the third joint somewhat infus- cated. The ground-color of the front is greenish, metallic but not shining, covered with rather thick white dust, so that the whole front assumes a pale grayish-green appearance. The greater part of the upper side of the thorax has a similar, but somewhat more green coloring ; however, the humeral region, and in connection with it, a large lateral spot near the transverse suture, the lateral margin above the root of the wing and the posterior corners are of a yellowish color. Scutellum grayish- ereen with yellowish’ margin. Almost the whole upper half of the pleure is greenish-gray, yet the color of the described speci- men is not sufficiently matured for a more precise statement about the extent of this color; the metathorax is gray. The first ab- dominal segment is blackish at its basis; the three following segments have each on the anterior margin a broad, black band, which is gradually tapering towards the lateral margin. Feet PSILOPUS. 929 pale-yellow ; tarsi towards the tip only very little darker, but their small last joint more or less distinctly infuscated, especially that of the fore tarsi. Cilia of the tegule whitish. Halteres white-yel- lowish ; their knob infuseated on its lower half. Wings hyaline, only a little tinged with grayish; the last segment of the fourth longitudinal vein is only very gently inflected forward from its middle, is in general somewhat distant from the third longitudinal vein, and approaches it, especially at its end, less closely than is the case in the preceding species, Hab. Middle States. Gen. XLII. PSILOPUS. The genus Psilopus can be easily distinguished from the re- lated genera by its peculiar slender structure, the slenderness of its feet, the broad and excavated vertex and the peculiar neuration of its wings. The peculiarity of the neuration consists, besides the great proximity of the posterior transverse vein to the margin of , the wing, especially in the structure of the fourth longitudinal vein; this vein either does not reach the margin of the wing at all, or becomes extremely thin before it reaches it; at the same time it emits anteriorly a robust branch, which bends forward either in a smooth or in an angular curve and ends in the neigh- borhood of the third longitudinal vein into the margin of the wing ; strictly speaking, this anterior branch is the real continua- tion of the fourth longitudinal vein; its apparent continuation beyond the origin of this branch is an adventitious appendage ; and that such is really the case, is proved by those exotic species, where this appendage is entirely wanting. The species of Pstlopus exhibit in the structure of the head and of its parts, especially in the antenne, as also in the structure of the feet, of the wings, and of the male organs of copulation, numerous plastic differences, which may easily mislead to the for- mation of smaller genera. The greater part of these characters are merely ornaments of the males and exclusively specific distinctions, so as to be of little use for the definition of smaller genera; this applies even to the most striking among the other characters, as, for instance, to the either dorsal or apical position of the arista, the either very short or very long pubescence of the second joint of the antenne ec. ; these also afford no sharp limits, and there 230 DIPTERA OF NORTH AMERICA. [PART IL. are species, where the two sexes do not agree in these characters. Mr. Bigot divided the genus Psilopus into the following twelve smaller genera: Megisiostylus, Mesoblepharus, Agonosoma, Mar- garitostylus, Oaristylus, Condylostylus, Eurostomerus, Dasypsi- lopus, Heteropsilopus, Psilopus, Sciapus, and Gidipsilopus. In accordance with what I have said above, I cannot adopt these genera, based in part upon differences in the ornamentation of the feet in the male, and upon other distinctions of a similar value. If the genus Pszlopus is to be further subdivided, this division will have to be based upon the observation, that the species of Psilopus diverge in two directions in their general habitus; one of these two sections embraces all our Huropean species, and a number of similar species, mostly from Northern Asia and North America, the other section includes the large majority of the extra- European species. If these two branches are to be raised to in- dependent genera, then such characters must be found, which can distinctly separate them from each other. There is no want of plastic distinctions, which may be used for such a purpose, but they are so manifold and of such an intricate nature that I believe to have found a more useful mark of distinction in the color of the cilia of the tegule, which in all the species of the first branch known to me are whitish, in those of the second branch however black. These characters have been used by me merely for the establishment of the two subsections of the genus Psilopus. Although the species of Pszlopus are so numerous and appa- rently resemble each other so much, nevertheless they can be easily distinguished, if only the necessary attention is paid to the plastic differences and not merely to the differences in color, which are often insignificant and more or less inconstant in almost all the species. The males of the different species especially can be easily distinguished, as they are remarkable by peculiarities in the structure of their antenne, wings and feet, which belong to their sex only; they offer, besides, useful marks of distinction in the anal appendages; among the females of the smaller species, how- ever, the distinction becomes. sometimes rather difficult. Of the characters taken from the coloring, the most unreliable are those taken from the coloring of the head, thorax, and abdomen, espe- cially in those species, the metallic coloring of which is shifting between the blue and the green; a little more available are the characters based upon the picture of the wings, if only we do not PSILOPUS. 231 neglect to» observe that this picture, at least in many species, varies a great deal not only in intensity, but also in extent; use- ful and rather reliable are the characters based upon the coloring of the feet, but of course then only, when the sex is stated, as in a good many species the feet of the females are much paler than those of the males. The genus derives its name (from 4raos, slender, and zovs, foot) from the great slenderness of the feet, peculiar to all the species. The species of Pstlopus are numerously represented in all parts of the world. Say has described several North American species of Psilopus. Wiedemann has added a few more. His descriptions, even if judged with leniency, will be found very unsatisfactory, as they relate merely to differences in color, and often do not even state to what sex the specimen belonged; some of them can be applied to whole series of closely allied species. Mr. Macquart’s and Mr. Walker’s descriptions are not much better ; those especially which the latter published in the Diptera Saundersiana are remarkable for their entire uselessness, so far that one may be sure not to find in them precisely those data which are indispensable for the re- cognition of the species of Pstlopus and for their distinction from each other. - ‘The insufficiency of the existing descriptions renders the deter- mination of the species very difficult; generally we reach only possibilities, sometimes probabilities, very seldom certainty. 9. guttula Wied. Of this species there is a well-preserved pair in Wiede- mann’s and another in Winthem’s collection. "Wiedemanun’s state- ment that this species is from Savannah, is a mistake, corrected br himself, and replaced on the etiquette by “Rio Janeiro.” In Win- them’s collection also, Brazil is mentioned as the locality. There- fore this species must be stricken out from the list of North American species. As Wiedemann’s description is not sufficient, I give a more accurate one as follows :— P. suttula Wiepv. % and ?.—Obscure eneo-viridis, capite, scutello et thorace postico interdum violaceis, abdomine cupreo, in apice viola- ceo, in basi plerumque viridi, facie nuda, pedibus simplicibus, obscuris,. alarum fasciis duabus nigris valde dilatatis, antice conjunctis et postice abbreviatis, in vena longitudinali quarta confluentibus, ita ut guttam hyalinam majusculam ineludant. *,. Tibiis obscure piceis, halteribus ex fusco nigris, abdomine nigro-fas- ciato, appendicibus hypopygii minuti parvis, nigricantibus. 238 DIPTERA OF NORTH AMERICA. [PART II. ©. Tibiis ex flavo testaceis, halteribus flavis, abdomine subobsolete nigro- fasciato. Dark bronze-green, head, scutellum and hind part of the thorax sometimes violet; abdomen coppery, at the tip violet, at the basis usually green ; face glabrous, feet plain and dark colored; the two broad black bands on the wings are united in front and shortened behind; on the fourth longitudinal vein they again run together, so as to enclose a rather large hyaline drop. %,. Tibie dark pitch-brown, halteres brown-black; abdomen with black bands; the small hypopygium with small black appendages. ©. Tibia yellow-brownish ; halteres yellow; abdomen with but rather indistinct black bands. Long. corp. 0.18—0.22. Long. al. 0.17—0.19. Syn. Psilopus guttula WiepEMANN, Auss. Zweifl. II, 222, 18. Of moderately bright, dark-metallic color, which seems to be chiefly green on head and thorax; on the abdomen principally coppery and violet. Head shining green, rarely shining black- green, though the front is always steel-blue or violet; on the ver- tex, besides the usual bristles, it is also beset with black hairs. The face is not very broad, without hair, and exhibits but a slight trace of whitish dust. Antenne black, of moderate size; the bris- tles of the second joint not very long. Palpi black, beset with a few stiff black hairs; proboscis brown-black. Thorax dark metal- lie green, usually on the lateral margin and sometimes on the whole posterior half of a’ violet color. The bristles of the thorax and the four bristles of the green or violet scutellum are black ; pleuree green, on the posterior margin more black, everywhere covered with white dust. Abdomen towards the tip, especially in the male, very pointed; its color is usually chiefly coppery, at the tip always violet, near the basis often green; sometimes the violet color extends almost over the whole abdomen, but even then the posterior margins of the fore and middle abdominal segments remain of a coppery color. In the male each of the abdominal segments has near the basis a broad, but not sharply defined black band ; there are also traces of them in the female. The black hair on the abdomen and the black bristles before the posterior margin of each segment are but of middling length. The extremely small hypopygium is black; its short appendages are blackish. Coxe black with thin white dust, the foremost ones with white hair and in the vicinity of the tip with a few black bristles. Femora black, on the under side with rather long erect white little hairs, inter- ESILOPUS. 239 spersed now and then with a little black hair. Tibise of the male brown, near the root black-brown; the middle tibiz on the out- side with a regular row of obliquely inserted black bristles ; on the outside of the fore tibize there is a row of five or six black bristles, which does not reach as far as the tip; the hind tibiz are without bristles. Tibize of the female yellow, near the root brown; the fore and middle tibiz with a few sparse bristles; the hind tibiz, as in the male, without bristles. Tarsi black-brown, those of the female less dark than those of the male, in both sexes plain; the fore tarsi of the male ‘are about 14 the length of the tibie, their first joint is about 14 the length of the following joints together, and beset upon the middle of the outside with two black bristles ; its middle tarsi are not quite 14 the length of the tibiee, their first joint is more than 14 the length of all the other joints together, and beset with a few black bristles; its hind tarsi are somewhat stout, shorter than the hind tibie, and their. first joint not much longer than all the others together. The fore and middle tarsi of the female are somewhat shorter than those of the male, and their first joint is much less elongated ; its hind tarsi are more slender than those of the male. The tegule have a black margin, and are fringed with long black cilia. The halteres of the male are brown- black, those of the female yellow. Wings hyaline with the usual two black bands, united on the anterior margin and abbreviated before the posterior margin; they expand in a rather unusual manner, and coalesce again upon the fourth longitudinal vein, so as to enclose a large drop in the first cell of the posterior margin ; on the anterior margin the darker coloring begins rather far before the end of the first longitudinal vein, and does not reach to the end of the third vein; the anterior branch of the fourth longitudinal vein forms an acute angle with it and turns then at a somewhat rounded angle of about eighty degrees towards the tip of the wing, pursuing this course in a rather straight line; the posterior transverse vein is straight, has, however, a somewhat oblique position. Hab. Rio Janeiro. (Coll. Wied. and Winth.) 10. caudatus Wied. Wiedemann’s statements seem to prove beyond doubt, that this species belongs to the relationship of P. scobinator ; among the species of this kind I know but one which, like caudatus, is distinguished by the extraordinary length of the hairs at the ex- DIPTERA OF NORTH AMERICA. [PART i treme tip of the male abdomen; this species, which I have called P. caudatulus, differs, however, from P. cuwudatus by its smaller size too much, to be mistaken for it. In Wiedemann-Winthem’s collec- tion no information whatever is to be found about P. caudatus. In the Berlin Museum there is a specimen of P. comatus, under the name of P. caudatus; I cannot, however, acknowledge the correct- ness of this determination, as Wiedemann distinctly says that the female of his P. caudatus has no black femora, like the male, but yellow ones, while this is not the case with P. comatus. The typical specimen of P. caudatus is in Westermann’s collection. ll. virgo Wied. The description of a female, which also seems to belong to the circle of relationship of P. scobinator. The statements which Wiedemann gives about it are so uncertain, that no conclusion as to the species to which the described specimen belonged can be drawn from them. The size, as stated by Wiedemann, is more con- siderable than the size of the females of all the species of this rela- tionship that are known tome. The typical specimen is not to be found in Wiedemann’s collection, so that a satisfactory solution as to this species is probably never to be expected. 12. mundus Wied. Of this species there are two males in Winthem’s collection, marked as Wiedemann’s types. Had I known them be- fore I published the Eighth Part of the “ Neue Beitrage,” I should not have ventured to describe in that volume P. ci/iatus as a species different from P. mundus. Certainly both specimens in Winthem’s collection are very much smaller than the male, which was the type of my description of P. ciliatus, and their coloring is darker and more distinctly violet; but in all the plastic characters there is much similitude between them and the male, which I have de- scribed. The only plastic difference, which I can discover, is the following: in P. mundus there is, besides the row of bristles on the outside of the fore tibiz, also a second row, placed further towards the inside, and which is tolerably complete; in P. ciliatus this second row is also present, but it is as complete as in P. mundus only in the vicinity of the root of the tibiz, further on it is (appa- rently) more incomplete; however, no accurate judgment can be based on a single specimen, and moreover the difference is so trifling, when compared to the great conformity in the extraordinary struc- ture of the wings and of the fore tarsi, that too much stress is not to be laid upon it. As the name “ czliatus’ has already been be- stowed upon this species, I may be permitted to retain it, until the identity of the species, so named, with P. mundus has been more positively established. A separate description of the latter is unne- cessary, as no mistake can occur if a proper attention is paid tothe description of P. ciliatus, as well as to what has just been said about these species. 12. radians J/acq. First described in the “ Suites @ Buffon ;” the same PSILOPUS. | QAI description is found in the Dipttres erotiques 11, 2, 122, only in the latter it is said “jambes POSTERIEURES e¢ infermediatres jaungtres,” in- stead of “jambes ANTERTEURES et intermediaires jaundtres.” That this is merely a misprint, is evident from what Mr. Macquart says in Dipt. exot. II, 2,123, at the top of the page. All the characters stated by Mr. Macquart are also those of P. longicornis Fabr., so that Macquart’s species cannot be distinguished from it. 14. portoricensis Macq. A very incomplete description of a female first given in the “ Suites 2 Buffon,” and then repeated in the Dipteres exotigues, JI, 2,121. Mr. Macquart again mentions this species in Dipt. exot. Suppl. J, 120, and furnishes there a figure of the wing (tab. xi, fig. 17). The only character contained in the description and which may lead at once to the recognition of this species, is the pubescence at the basis of the arista : another character of this kind may perhaps be found in Macquart’s figure of the wing, where the anterior branch of the fourth longitudinal vein is closely approxi- mated to the margin of the wing. I know of no species possessing these characters. 15. sipho Jacg. Ihave already remarked that the species, which Mr. Macquart has described under this name, is quite different from the genuine sipho Say, and probably identical with P. jucundus, with which it will have to be united as a synonym. 16. incisuralis J/acg. The description (Dipt. exot. Suppl. I, 120) has been drawn from a female; in an observation, however, Mr. Mac- quart declares that he possesses a male belonging to this female; the characters, however, which he furnishes render it very doubtful that they belong together. I therefore take into account the de- scription of the female only. It belongs to the group of species which resemble by the picture of their wings P. diffusus, superbus, &c., but does not seem to be identical with any of these species ; it has also some resemblance with a female in my collection, from Brazil, which Wiedemann himself had determined as P. guttula, but which, nevertheless, does not belong to this species; however the band on the wing is much broader and connected with the spot near the tip of the wing not only at the anterior margin, as it is in the other species, but also upon the fourth longitudinal vein. Therefore incisuralis seems to be an unknown, but independent species. 17. delicatus Walk. still the basis of the fore and middle tarsi yellow. Long. corp. 0.15— 0.16, Long. al. 0.15.—0.16. Syn. Psilopus scobinator Loew, Neue Beitr. VIII, 91, 9. Male. Handsome shining, green, sometimes partly stee]-blue. Palpi black ; proboscis brownish-yellow. Face with a long whitish pubescence and not very closely dusted with white. The second joint of the antenne with moderately long bristles; the arista itself only of the usual length. The delicate scattered pubescence of the front generally yellowish, more seldom whitish; the usual black bristles upon the ocellar tubercle and in the upper eye- corner rather long. The bristles upon thorax and scutellum are also rather long. The hind part of the abdomen is more pointed in the shape of a cone than in most of the other species ; the black bands at the basis of the segments of the abdomen are narrow, broader only upon the segments. The short pubescence of the abdomen is black; upon the first segment, as also on the anterior part of the lateral margin and on the greater part of the venter it is \ PSILOPUS. 269 whitish; the black. bristles before the incisures are not remarkably long; the bristle-like hairs at the extreme tip of the abdomen are rather long. The small hypopygium is black, with extremely | small black appendages. Coxe black, dusted with white, the fore- most with a white pubescence and a few black bristles. Femora black with a green reflection; the anterior ones light yellow at the extreme tip; upon the under side of all there is a delicate, erect, rather sparse pubescence of medium length. Tibie yellow; the hindmost colored with blackish-brown to a rather considerable extent at the tip. Fore tibiz upon the upper side with about four short black, minute bristles, upon the hind side with about six still shorter ones. Middle tibie upon the first half of the hind side with three not very long black bristles ; a perceptibly longer bris- tle is to be found upon the first quarter of the front side, another near its end; immediately before the end on the under side an unusually long, straight, diverging, black bristle assumes the shape of a rather striking spur of the tibia. On the hind tibize, besides the black bristles inserted at the tip, there is but one bristle de- serving to be noticed, upon the first third of the outside. Fore tarsi slender, somewhat longer than the tibize; their first joint yellow, only at the extreme tip brownish-black, nearly once and a half the length of the following taken together; the latter are brownish-black ; from the second to the fourth of rapidly decreasing length, the fifth as long as the fourth. There are no bristles nor any unusual pubescence on the fore tarsi. Middle tarsi brownish- black, considerably shorter than the tibie; their first joint about once and a quarter the length of the following taken together, its whole length upon the under side fringed rasp-like with short black bristles, crooked downwards, and inserted in a row on both sides ; the four following joints of decreasing length. Hind tarsi black, hardly two thirds of the length of the tibie ; their first joint little longer than the following taken together; the second to fourth joint of rapidly decreasing length; the two last joints of an equal length, somewhat flattened. Halteres yellowish with blackish peduncle; tegule with black cilia. Wings hyaline with black veins ; the end of the first longitudinal vein is a considerable dis- tance before the middle of the wing; the anterior branch of the fourth longitudinal vein diverges from it at an angle which is very nearly a right one, and turns then arch-like towards the margin, which it reaches rather far before the apex, quite near the tip of 270 DIPTERA OF NORTH AMERICA. [PART II. the third longitudinal vein; hind transverse vein moderately ob- lique and nearly straight. _ female. Face somewhat broader than in the ¢. All pretes perceptibly shorter. Abdomen, in the usual position of the seg- nents, without black bands. Fore coxe yellow, at the extreme basis often colored with gray; their white pubescence much shorter and the black bristles more striking. All the femora altogether yellow, fringed upon the under side with but very short, erect, whitish hairs. 'Tibiz quite yellow, the hindmost somewhat infuscated only at the extreme tip. The bristles of the tibie are quite like those of the ¢, still some of the bristles are missing, or at least shorter. Tarsi plain, somewhat shorter than in the ¢; the first joint of the middle tarsi brownish-yellow, upon the under side with but a few very short black bristles. Hab. New York, Illinois. (Osten-Sacken. ) Observation 1.—With P. scobinaior begins a series of very closely resembling species, which agree in a remarkable manner not only in size and coloring, but also in the majority of the plastic characters. The structure of' the middle feet in the ¢ shows differences, which leave no doubt as to their specific dis- tinctness. The distinction of their females offers such difficul- ties, that I am unable to overcome them with the materials at my command. JI have received P. scobinator in so large numbers, that the 9 belonging to this species is surely abundantly repre- sented among them; but whether I have not confounded with it females of the three following species, I am not able to tell. Some of the females, I suspect, belong to P. caudatulus, others may be P. inermis, but I am not positively certain about any one of them. Positive characters for the distinction of the females of these species can only be acquired by the observation of the species in life. Observation 2.—There is no doubt that P. fone Say belongs to the present group. Whether it is one of the species known to me, and which of them, I cannot decide, as Say does not mention any of those plastic characters by which alone they can be distinguished, and as the ¢ specimen sent by Say to Wiedeman has not been preserved in the collection of the latter. PSILOPUS. 271 12. P. caudatulus Lozw. %.—Parvus, nitidissimus, viridis vel ex viridi chalybeus, facie pilosa, alis immaculatis, anteriore venz longi- tudinalis quart ramulo arcuatim ducto, halteribus flavis. *,. Abdomine fasciis nigris angustis ornato et in apice pilis solito multo longioribus vestito, femoribus nigris, viridimicantibus, summo femoruim anteriorum apice tibiisque omnibus flavis, apice tibiarum posticaruin tarsisque omnibus ex fusco nigris, tarsorum anteriorum basi tamen flava, calcare tibiarum intermediarum longissimo, primo tarsorum inter- mediorum articulo setulis incurvis scabro. Small, very shining, green or bluish-green; face hairy; wings without picture; the anterior branch of the fourth longitudinal vein arched ; halteres yellow. *%. Abdomen with narrow black bands, at the tip with much longer hairs than usual, femora black, with a greenish reflection, the extreme tip of the four anterior femora, and all tibie yellow; the tipof the hind tibia, and all tarsi brownish-black ; still the first joint of the fore tarsi yellow, the spur of the middle tibize very long; first joint of the middle tarsi beset with crooked bristles, rasp-like. Pe ieile= che Log. corp. 0.10. Long. al. 0.15, Syn. Psilopus caudatulus Lozw, Neue Beitr. VIII, 93, 12. It resembles the P. scobinator so much, that the statement of the slight differences will be perfectly sufficient for its recognition ; the hairs at the tip of the abdomen are much longer, more bristle- like, and when well preserved, are of the same length as the four last segments of the abdomen, whilst in P. scobinator, the two which are longest among them are but little longer than the last segment. Hab. Missouri. (Schaum.) Illinois. (Le Baron.) Observation.—The name which I have given to this species is intended to remind of P. caudatus Wied., which undoubtedly belongs to the same group; but, by its larger size, it seems to be different from the species known to me. In the Neue Beittrige, in consequence of a mistake, some incorrect statements have been made by me about P. caudatulus. Its resemblance with P. scobinator is so great that one would be very much inclined to take it for a mere variety of it, if the difference in the length of the hairs at the tip of the abdomen was not so considerable, and if the distinction of the other species of this group, otherwise agreeing perfectly in all characters, did not likewise rest on some single plastic character. 272 DIPTERA OF NORTH AMERICA. [PART II. 13. P. catcaratus Lorw. %.—Parvus, nitidissimus, viridis vel ex viridi chalybeus, facie pilosa, alis immaculatis, anteriore vene longitu- dinalis quarte ramulo arcuatim ducto, halteribus flavis. *,. Abdomine fasciis nigris angustis ornato, femoribus nigris, viridi- micantibus, summo femorum anteriorum apice tibiisque omnibus flavis, tibiarum posticarum apice tarsisgue omnibus ex fusco nigris, primo tamen tarsorum anticorum articulo flavo, calcare tibiarum intermedia- rum longissimo, primo tarsorum intermediorum articulo simplici. Small, very shining, green or greenish-blue ; face hairy; wings without picture, the anterior branch of the fourth longitudinal vein arched; halteres yellow. *,. Abdomen with narrow black bands; femora black, with a greenish lustre, the extreme tip of the four anterior femora and all tibiz yellow; the tip of the hind tibize and all tarsi brownish-black; still the first joint of the fore tarsi yellow; the spur of the middle tibiz extremely long ; the first joint of the middle tarsi plain. Ois) Vahey aie) oo one. corp... 0:15.) pylbong yal Oglo Syn. Psilopus calcaratus Lozw, Neue Beitr. VIII, 93, 10. T am unable to mention any difference from the male of the P. scobinator, except that the middle tarsi are somewhat longer, namely, as long as the tibia, and that their first. joint upon the under side is not fringed rasp-like, with numerous, crooked bristles, but has only a few scattered straight bristles. Hab. Carolina. (Zimmermann.) 14, P. imermis Lorw. %.—Parvus, nitidissimus, viridis vel ex viridi chalybeus, facie pilosa, alis immaculatis, anteriore vene longitudinalis quart yamulo arcuatim ducto, halteribus fiavis. 4,. Abdomine fasciis nigris angustis ornato et in apice pilis solito longicri- bus nullis vestito, femoribus nigris, viridi-micantibus, summo femorum anteriorum apice tibiisque omnibus flavis, apice tibiarum posticarum extremo tarsisque omnibus ex fusco nigris, tarsorum anteriorum basi tamen flava, calcare tibiarum intermediarum brevissimo, primo tarsorum intermediorum articulo simplici. Small, very shining, green or bluish-green, face hairy; wings without picture, the anterior branch of the fourth longitudinal vein arched ; halteres yellow. *. Abdomen with narrow black bands, at the tip without hairs longer than usual; femora black, with greenish lustre, the extreme tip of the four anterior femora and all tibie yellow, the extreme tip of the hind tibize and all tarsi brownish-black, still the basis of the fore and middle PSILOPUS. ya tarsi yellow; the spur of the middle tibie very short; the first joint of the middle tarsi plain. OF ks gs a, wm ong, corp.10.15. ...\Long,, al. 0.15. Syn. Psilopus inermis Lorw, Neue Beitr. VIII, 93, 11. This species is likewise most closely allied to the ¢ of P. scobinator. In the coloring there are no differences, except that in P. inermis the hind tibiz are somewhat infuscated at the very extreme tip, while in the ¢ of scobinator the blackish-brown coloring is extended nearly over the whole of their last quarter, and that in 7nermis the first joint of the middle tarsi is brownish- yellow nearly to the middle. Whether these differences in the coloring are constant, further observations must show. ‘The plas- tic differences, which secure the specific distinctness of anermis from the two previous species lies in the structure of the middle feet. Whilst in the latter that bristle, which is inserted near the tip of the tibize upon the inner side, forms an unusually long, diverging spur, and much exceeds in length the bristle inserted on the front side of the tip, in P. enermis the bristle inserted on the inner side is not only the much smaller one, but is also not diverging ; the remaining bristles of the middle tibiz are consider- ably longer than in scobinator and calcaratus ; the first joint of the middle tarsi is plain, as in calcaratus, but has upon its under side a still smaller number of very short, straight bristles; the fore and middle tarsi are somewhat longer than in the two previous species, still this difference is but trifling. Hab. Pennsylvania. (Osten-Sacken.) II. TEGULA WITH PALE CILIA. A. Antenne entirely black. 15. P. scintillams Lorw. 4% and $9.—Totus nitidissimus, viridis vel ex viridi chalybeus, abdomine interdum ex aureo vViridi, antennis nigris, coxis anticis pedibusque flavis. *,. Alarum costa breviter ciliata, hypopygii appendicibus atris. ©. Alarum costa non ciliata. _ Very shining, green or bluish-green, abdomen sometimes golden- “green antenne black; fore coxe and all the feet yellow. *,. Costa with short cilia; appendages of the hypopygium Hack: Q. Costa not ciliated. Long. corp. 0.14—0.16. Long. al. 0.15—0.17. Syn. Psilopus scintillans Lorw, Neue Beitr. VIII, 94, 13. 18 274 DIPTERA OF NORTH AMERICA. [PART II. Male. Very handsomely shining, green, the abdomen, except- ing the two last segments, gilded. Proboscis dingy yellow, the small palpi black, with white hairs. Face without hairs, dusted with white. Antenne entirely black, small; the second joint with short, minute bristles; the arista itself of only moderate length. Front with the usual black bristles, which have but a moderate length, otherwise bare. ' Bristles upon scutellum and thorax of moderate length; upon the latter there are only two bristles. The black hairs of the abdomen are very scattered, and the black bristles before its incisures are rather short. The small hypopygium is black; its external appendages are very narrow, black, and with black hairs. Fore coxe pale-yellow, with scattered and rather short whitish hairs, and beset with several white bristles. Middle and hind coxe black. Feet very long and slender, pale-yellow. Femora slender, upon the under side sparely fringed with short, minute, whitish hairs. Tibiee likewise very slender, without bristles, with a very short black pubescence, which is diverging fringe-like on the middle tibize and is much closer upon their under side. Fore tarsi extremely slender, more than once and two-thirds the length of the tibiee; their first joint alone somewhat longer than the tibize, brownish-yeilow ; the follow- ing joints brownish-black and of decreasing length. Middle tarsi likewise very slender, about once and a half the length of the tibie ; their short black pubescence diverging, so that it appears fringe-like; their first joint brownish-yellow, at the extreme tip brownish-black ; the following joints brownish-black and of de- creasing length. Hind tarsi nearly as long as the tibie; first joint brownish-yellow, and but little longer than the following joints taken together; the latter brownish-black and of decreasing length. All the tarsi entirely without bristles. Halteres pale-yellow with a blackish peduncle; tegulee blackish with whitish cilia. Wings on the anterior margin, from their basis to the tip of the second longi- tudinal vein, regularly ciliated with rather stout, minute, black hairs; the third longitudinal vein rather distinctly curved back- wards at its end; the anterior branch of the fourth longitudinal vein diverges from it at a nearly right angle and turns then at a very rounded, somewhat obtuse angle towards the margin, which it reaches very near before the apex and not far from the tip of the third longitudinal vein; posterior transverse vein rather oblique and somewhat inflected. PSILOPUS. Dir. Female. It resembles the male very much, still the pubescence and bristles of the body are shorter, also the anterior margin of the wing is not ciliated. The delicate, minute white hairs upon the under side of the femora are hardly perceptible. Middle tibie with a much shorter, not diverging pubescence, but with a few minute black bristles, which are not to be found in the ¢. Tarsi somewhat shorter, otherwise of a similar structure, still the middle tarsi only with a quite short, not diverging pubescence, and the first joint of the hind tarsi fully as long as the four following joints taken together. Tegule sometimes rather yellowish. Hab. Middle States. (Osten-Sacken.) B. The two first joints of the antenne pale. 4. Fore femora in both sexes, or at least in the male, without yellow thornlike bristles upon the under side. 1. Abdomen not yellow at the basis. 16. P. palliems Wirp. 7% and 9.—Ex viridi cinereus, opacus, pro- boscide, palpis, duobus primis antennarum articulis, ventre, coxis pedi- busque flavis, coxis posterioribus fusco-maculatis. *%,. Tarsorum anticorum articulo quarto subdilatato, albido. ©. Infero femorum anticorum latere setis validis flavis armato. Greenish-gray, without lustre, halteres, palpi, the two first joints of the antenne, the venter, the cox, and the feet yellow, the four posterior coxe spotted with brown. %,. The fourth joint of the fore tarsi slightly enlarged, whitish. ©. Under side of the fore femora bearing stout yellow bristles. Long. corp. 0.23—0.26. Long. al. 0.22—0.24. Syn. Psilopus pallens Wiepemann, Auss. Zweifl. II, 219, 11. Psilopus albonotatus Lozw, Neue Beitr. V, 4. Psilopus pallens Lozw, Neue Beitr. VIII, 97, 17. Male. Everywhere closely covered with a grayish or whitish- gray dust, from below which the metallic bluish-green ground shines distinctly, although not strongly, through. Proboscis brown ; palpi whitish-yellow. Face broad, without hairs, very closely - covered with white dust. The two first joints of the antenne yellowish, the second beset with very short minute black bristles ; third antennal joint brown, rounded ; arista proportionally short. Front with a close white, round the ocellar tubercle with brownish- gray, dust, without hairs, the usual black bristles upon it of medium 276 DIPTERA OF NORTH AMERICA. [PART II. length. The opaque thorax, dusted with grayish, has two longi- tudinal lines, distant from each other upon the middle, and two other incomplete longitudinal lines of a brown color, occupying the place of the lateral stripes. Bristles of the thorax proportion- ally short. Scutellum with two bristles. The abdomen, dusted with grayish and rather opaque, has upon the second segment a jarge blackish, triangular spot, with its point directed backwards ; upon each of the following segments there is a similar spot, which is connected with the rather narrow black anterior margin of the segment, and the color of which is changing from a dusky-bronze into grayish-green. The structure of the hypopygium and of its appendages is nearly as in P. albifrons Meig.; the external appendages are hardly half so long as the inner ones and have the form of a small elliptical lamella; their color is brown, their pubescence near the basis more delicate, shorter and pale, at the tip coarser, longer, and black; the inner appendages form a brownish-yellow forceps, dark-brown at the tip. Coxee and feet yellowish, still the middle and hind coxe rather broadly infuscated. Fore coxe beset only with a delicate, moderately long, yellowish- white pubescence, without stouter bristles. All femora slender, upon the under side very glabrous; the few pale. hairs which are to be found there are extremely short, and therefore hardly per- ceptible. Pubescence of all the tibie very short, that of the middle tibiz somewhat longer and more diverging. Fore tibiz upon the upper side with a few slender minute bristles, one of which is inserted at their tip. Middle tibie generally infuscated upon the two last thirds of their upper side; upon their ante- rior side, not far from the basis, a more perceptible small black bristle is inserted; otherwise they are without bristles. Hind tibiee with a few very small bristles at the tip, otherwise as good as without bristles. Fore tarsi slender, double the length of the tibize ; their first joint somewhat longer than the tibia; the three following joints of nearly the same length; the fourth joint some- what flattened from the sides, whitish ; fifth joint only about half as long as the fourth, dark-brown. Middle tarsi once and a half the length of the tibis, slender; the first joint distinctly longer than the following taken together; the latter of a decreasing length, the last one infuscated. Hind tarsi somewhat shorter than the tibice, their first joint distinctly shorter than the second, the last one somewhat infuseated. Halteres yellowish; tegule with PSILOPUS. QT Yt a narrow black border and yellowish-white cilia. Wings rather large, of an elliptical outline, tinged with brownish-gray ; the third longitudinal vein is but little curved backwards at the end; the anterior branch of the fourth longitudinal vein, the origin of which lies nearer to the posterior transverse vein than to the margin of the wing, leaves this vein at an obtuse angle, and turns in a flat curve towards the margin, which it reaches a little before the apex and not far from the tip of the third longitudinal vein ; the poste- rior transverse vein lies proportionally far away from the margin, is but moderately oblique and not inflected. Female. It resembles the ¢ very much, but shows the follow- ing differences: The color of the dust upon front, thorax, scutel- Jum and abdomen is more yellow-grayish. The blackish, triaugu- lar dorsal spots of the abdomen are indistinct. The fore coxe have, besides the yellowish-white pubescence, on the inner and outer margin, as also at the tip, numerous yellow bristles. Feet shorter and of stouter structure than in the ¢. Upon the first half of the under side of the fore femora there are five diverging stout thorn-like bristles of yellow color. All the tibiw are sparely beset with single black bristles of medium length. Tarsi dis- tinctly shorter than in the ¢, from the third joint infuscated, the last joint dark brown, the second to fourth joints of the fore tarsi decreasing in length more rapidly than in the ¢. Wings somewhat smaller and less obtuse than those of the ¢; tke neura- tion does not show any perceptible difference. Hab. New York. (Osten-Sacken, who found it frequently in June and July in the buildings near the Bowling Green and the Battery, on walls and windows in the rooms. ) Observation 1.—The present species is not only an entirely European form, but also without the least doubt perfectly identi- cal with P. albonotatus, which I have discovered at Rhodus and described in “‘ Neue Beitr. V.” The comparison of two ¢ of the latter with several ¢ of P. pallens shows, that there is no per- ceptible difference between them. Observation 2.—At the Imperial Museum in Vienna there are two specimens of P. pallens marked “ New Holland.” The simultaneous existence of the species in North America and Europe might lead to believe in the possibility of its also occur- ring in New Holland. However, my reasons for doubting this at present are as follows: the pins bearing these specimens are easily 278 DIPTERA OF NORTH AMERICA. [PART It distinguished from others, and among all the other Dolichopodidz of the collection, there are only two specimens on similar pins, and both are also marked “‘ New Holland.” A most careful compa- rison of the latter specimens showed that they are P. sipho Say. This circumstance renders it very probable that there was a mis- take in the statement of the habitat. 2. Abdomen at the basis yellow, not metallic. a. Tarsi for the most part black. 1%. P. wariegatus Lorw. (.—Viridi, chalybeo et cupreo varius, modice nitens, proboscide, palpis, primis duobus antennarum articulis. abdominis basi, ventre pedibusque fiavis, coxis intermediis cinereo- maculatis, tarsis ex fusco nigris. Green, steel-blue and copper-colored, variegated, moderately shining ; pro- boscis, palpi, the two first joints of the antenne, the basis of the abdo- men, the coxe and feet yellow; middle coxe spotted with gray; ; tarsi brownish-black. Long. corp. 9.21. Long. al. 0.20. Syn. Psilopus variegatus Lozew, Neue Beitr. VII, 95, 14. Green, the most part of the upper side of the thorax and the anterior part of the single segments of the abdomen coppery-red, the front and seutellum blue. The lustre of the ground-color is moderated by a slight whitish dust. Face greenish-blue, closely dusted with white, reaching more downwards than usual; without hairs. Proboscis and palpi yellow. The two first antennal joints yellowish, the second with very short minute black bristles; the arista dorsal, moderately long. Front blue, slightly dusted with white, without hairs; its usual black bristles of a moderate length. The upper side of the thorax shows two longitudinal lines of a coppery-red color, which are separated by a broad green stripe; each of them coalesces with a large coppery-red lateral spot; the upper side of the thorax is very probably not so variegated in all specimens. The black bristles of the thorax of “medium length. Scutellum blue with a green tip; the pair of bristles inserted near its tip is rather large, that nearer to the basis is more slender and much shorter. Pleurze rather closely dusted with white; their hind margin colored with yellow. The first segment of the abdomen yellow, near the basis blackish, on the hind margin, excepting the middle, metallic-green and fringed with a row of long black bristles; the basal third of the second PSILOPUS. 279 segment and on each side a lateral spot, yellow; otherwise, the abdomen is metallic-green, at the basis of the segments handsome coppery-red, altogether covered with a slight whitish dust. The pubescence of the first segment of the abdomen is whitish and delicate, upon the remaining segments it is coarser and black ; the minute black bristles before the second and before the following segments differ but little from the remaining pubescence. Ven- ter yellow, with a very scattered and short pubescence, which has near its basis a whitish, towards its end a black color. Fore cox yellow with a rather short whitish pubescence and with a few stout whitish-yellow bristles. Middle and hind coxe likewise yel- low, still the first with a gray spot, which covers the larger part of its outside. Femora yellow, upon the under side with a hardly distinct whitish pubescence; the foremost with a single black bristle inserted upon the outside not far from the basis. The middle tibiz have a more distinct minute bristle upon the front side near the basis and a few at the tip, besides some small ones upon the hind side; the hind tibiz have upon the front side, not far from the basis, also one stout bristle and some quite small, hardly perceptible ones upon the upper and under side. Fore tarsi about once and two-thirds the length of the tibie ; their first joint alone of the same length as the tibiz, brownish-yellow; the following joints brownish-black and of decreasing length, still the third but little shorter than the second. Middle tarsi once and a-half the length of the tibize, of the same coloring and structure, only the first joint proportionally somewhat shorter. Hind tarsi but little shorter than the tibiz, brownish-black, at the basis more yellowish-brown, the first joint not quite as long as the second and third taken together. Halteres yellowish; tegule with a very. narrow black border and whitish cilia. The third longitudinal vein of the wings distinctly curved backwards near its end; the anterior branch of the fourth longitudinal vein diverges at a rather acute angle and turns then at a very rounded right angle towards the margin, which it reaches somewhat before the apex near the* tip of the third longitudinal vein; hind transverse vein strikingly oblique, not sinuated. Hab. Florida. (Osten-Sacken.) Cuba. (Gundlach.) Observation.—P. variegatus is very like the ? of P. psitta- cinus. The proportionally longer wings, the different position of the bristles of the scutellum, the much darker coloring of the 280 DIPTERA OF NORTH AMERICA. [PART II. tarsi and the proportionally somewhat lesser length of the first joint of the hind tarsi seem to prove its distinctness sufficiently. b. Tarsi but little infuscated towards the end. a. All the coxe entirely yellow. 1S. P. bicolor Lorw. ?.—Viridis, nitidissimus, proboscide, palpis, duobus primis antennarum articulis, abdominis basi et maculis laterali- bus, ventre, coxis pedibusque flavis. Green, very shining; proboscis, palpi, the two first joints of the antenne, the basis of the abdomen and spots on its side, venter, coxze and feet yellow. Long. corp. 0.13—0.14. Long. al. 0.13—0.14. Syy. Psilopus bicolor Loew, Neue Beitr. VIII, 96, 15. Green, very shining. Palpiand proboscis yellow. The gla- brous face and the front bluish-green, the former rather closely dusted with white, the latter with the usual black bristles, which have but an insignificant length, otherwise without pubescence. The two first joints of the antenne yellowish; the second with only extremely short minute black hairs. The black bristles of the thorax short. Scutellum with only two long black bristles. Pleure closely dusted with white, their hind margir yellow. First segment of the abdomen yellow, with a shining green hind mar- gin; the second segment likewise yellow, with a very large metallic- green spot, which only leaves unoccupied the basal one-third, the anterior corner and the lateral margin; the two following seg- ments shining green, with a yellow anterior corner and yellow lateral margin; the fifth segment only with a yellow lateral mar- gin. Venter entirely yellow. The pubescence of the abdomen is scarce, delicate and short, upon its upper side black ; the minute black bristles before the incisures are so short that they distinguish themselves but little from the remaining pubescence. All the cox and the very glabrous, long and slender feet pale yellowish. Fore cox with a short whitish pubescence and with a few hair-like ‘whitish bristles. Under side of the fore femora with extremely short minute whitish-hairs, under side of the middle and hind femora glabrous. Fore tibize entirely without bristles; middle and hind tibize with one short minute black bristle upon the out- side, not far from the basis and with some similar minute bristles at the tip. The very slender fore tarsi over once and two-thirds the length of the tibia; their first joint a little longer than the PSILOPUS, 281 tibia, the following joints of a decreasing length, the fifth joint infusecated. The slender middle tarsi nearly once and a-half the length of the tibie; their first joint distinctly shorter than the tibia; the following ones of decreasing length, the last one some- what infuscated. Hind tarsi about three-fourths the length of the tibie ; their first joint longer than the following taken together ; these are of a decreasing length, somewhat infuscated, still only the last is really brown. ‘The pubescence of all the feet is of a rather striking shortness ; its color upon the under side of the tibia and tarsi is not black, although they take the appearance of this color in some reflected light. Halteres pale-yellowish ; tegule with an exceedingly narrow black border and with yellowish-white cilia. The third longitudinal vein of the wings curved gently backwards at its tip; the anterior branch of the fourth longitudinal vein diverges from it under a rather acute angle and turns then at a rounded right angle towards the margin, which it reaches imme- diately before the extreme apex, near the tip of the third longi- tudinal vein ; the hind transverse vein very oblique, little inflected. Hab. Middle States. (Osten-Sacken. ) B. Middle coxe gray with yellow tip. 19. P. psittacinus Lorw. 4% and ?.—Aureo-viridis, modice nitens, proboscide, palpis, duobus primis antennarum articulis, abdominis basi, ventre, coxis anticis posticisque et pedibus flavis, coxis intermediis cine- reis, in apice flavis. *,. Alarum costa concava, breviter ciliata. ©. Alarum costa nec concava, nec ciliata. Golden-green, moderately shining, proboscis, palpi, the two first joints of the antenne, the basis of the abdomen, the venter, the fore and hind coxe, as also the feet, yellow; the middle coxe gray with yellow tip. =. The anterior margin of the wings concave, with a fringe of short cilia. Q. The anterior margin of the wings neither concave nor ciliated. Long. corp. 0.20—0.22. Long. al. 0.19—0.20. Syn. Psilopus psittacinus Lorw, Neue Beitr. VIII, 96, 16. Male. Golden-green, moderately shining. Proboscis and palpi yellow. Face greenish-blue, closely dusted with yellowish-gray, reaching much downwards, without hairs. The two first joints of the antennz yellowish, the second with very short minute black bristles. The arista dorsal, moderately long. Front blue or bluish-green, with a grayish-yellow or nearly whitish dust, without 232 DIPTERA OF NORTH AMERICA. [PART II. liairs, its usual black bristles of a very moderate length. Thorax, scutellum and abdomen with a slight yellowish dust, which moderates the lustre of these parts. The black bristles of the thorax of moderate length. The scutellum has only the pair of bristles at the tip, which is of a considerable length ; immediately near each bristle of this pair a much shorter black hair is inserted towards the outside. Pleure black with a green reflection and with a grayish-white dust; their hind margin gray or at least only in part yellowish. Abdomen green, towards its end generally some- what gilded; the first segment yellowish, at its basis blackish, on the hind margin metallic-green; on the second segment the ante- rior margin and corner, sometimes also the lateral margin, yellow; the third segment has generally, on the anterior part of the lateral margin, an elongated yellowish spot. ‘The scattered pubescence of the abdomen is rather delicate and long; upon the upper side it is black, whitish only upon the first segment; the pubescence of the venter is whitish near its basis, but becomes gradually darker towards the end. The black bristles before the incisures of the abdomen of a very moderate length. The external append- ages of the hypopygium small and very narrow, brownish-yellow. Fore and hind coxe pale yellow, the former with a snorter and more delicate whitish pubescence and with a few light-yellowish bris- tles; middle coxe gray with pale-yellowish tip. Feet yellowish. Femora slender, upon the under side sparely fringed with exceed- ingly short, minute whitish hairs; besides, upon the second half of the under side of the middle femora there is a sparse row of minute black hairs. Tibi slender and long; the usual black pubescence of the fore and hind tibiz is very short and appressed, that of the middle tibiz somewhat longer and more erect, there- fore almost fringe-like. The fore tibie, with the only exception of a rather small minute black bristle, inserted upon their outside, near the basis, are entirely without bristles. The middle tibiz bear no bristles whatever, distinguished from the other pubescence. Hind tibie upon the front side, not far from the basis, with a rather apparent little bristle, whilst those upon the upper and under side are less numerous, extremely small and therefore more difficult to perceive. Fore tarsi slender, nearly twice as long as the tibie ; their first joint for itself alone somewhat longer than the tibia, the following ones of decreasing length, the last one brown. Mid- dle tarsi slender, about once and a half the length of the tibie ; PSILOPUS. 983 the first joint distinctly shorter than the tibia, upon its front side somewhat sparsely ciliated with oblique minute black hairs; the following joints only with the usual short pubescence and of de- creasing length, the last one dark brown. The length of the hind tarsi somewhat exceeds three-fourths of the tibi ; their first joint is only somewhat longer than the following taken together; these are of decreasing length, somewhat infuscated, still only the last one dark brown. Halteres light yellow; tegule with extremely narrow black margin and with yellowish-white cilia. Wings with brown veins; the anterior margin is gently sinuated upon its larger second half, and forms before the tip of the second longitu- dinal vein a projecting angle, so that the whole wing acquires a quite unusual axe-like shape ; the whole anterior margin, as far as that angle, is delicately and equally ciliated ; the third longitudinal vein, near its end, is turned back very abruptly and unusually far ; the anterior branch of the fourth longitudinal vein diverges from it under a rather acute angle and turns then in a curve towards the margin, which it reaches not far from the tip of the third lon- gitudinal vein ; posterior transverse vein rather remarkably oblique, gently sinuated in the shape of an 8. Female. It resembles the male very closely. Besides the lesser length of the bristles on the whole body, and besides the somewhat lesser length of the feet, which are of the same color as in the ¢, there are only the following differences: the whole hind margin of the pleure is colored with yellow. The middle t#@iz are without the longer and erect pubescence of the ¥, but their pubescence is short and appressed as on the other tibis; there are, however, upon the front side near the basis one, and at the tip of the tibize a few more distinct minute black bristles, besides some smaller ones upon the hind side. The anterior margin of the wings is neither concave nor ciliated, the wings therefore of the usual form; the third longitudinal vein, near its end, is much less sud- denly and much less strongly curved backwards; the course of the - anterior branch of the fourth longitudinal vein is somewhat less in a curve, and the sinuosity of the hind transverse vein not so strong. Hab. Florida. (Osten-Sacken.) 284 DIPTERA OF NORTH AMERICA. [PART Tt: s. Fore femora upon the under side with thornlike bristles in both sexes. 1. All the coxe entirely yellow. 26. P. temer eeu. % and 9.—Laete viridis, proboscide, palpis, primis duobus antennarum articulis, pleurarum margine postico, abdo- minis basi, coxis pedibusque flavis, ciliis tegularum albicantibus, alarum vena transversa posteriore valde obliqua. *. Femora antica setulis subtribus armata ; appendices hypopygii majus- cule flave. @. Femora antica setis quatuor validis armata. Light green, proboscis, palpi, the two first joints of the antenne, the hind margin of the pleure, the basis of the abdomen, the coxe and feet yel- low; cilia of the tegule whitish ; hind transverse vein of the wings very oblique. *,. Fore femora generally with three minute bristles; the rather large appendages of the hypopygium yellow. ©. Fore femora with four stout bristles. Long. corp. 0.16—0.17. Long. al. 0.22. Syn. Psilopus tener Lorw, Berl. Ent. Zeitschr. VI, 217, 71. Light metallic-green, rather shining. Proboscis and palpi yel- low, the latter beset with a few minute bristles, which have in the *, a whitish, in the 9 a black color. The glabrous face, covered with white dust, is very broad, particularly upon its upper part, which is very convex. Antenne small, the two first joints yellow, the,second beset with a few short, minute black hairs upon the upper side; upon the under side with a few short, minute white hairs; the very small third joint is generally blackish, still it has sometimes a much lighter coloring. ‘The front is generally sky- blue, and, besides the usual black bristles, without pubescence. Upper side of the thorax sometimes more blue than green, rather distinctly dusted and beset with but a moderate number of black bristles. Pleurse, in consequence of a close white dust, grayish- green. The scutellum, which has two bristles, is sometimes green, sometimes purplish-blue. Abdomen shining hght-green, some- times rather golden-green ; its basis is in the 9 always, in the male generally, colored with yellow; the black bristles before the hind margin of the single segments are proportionally short. Hypopygium blackish-brown and dusted with white; its append- ages are pale yellow; the external ones are narrow lamelle and are fringed with a blackish pubescence, which is somewhat longer PSILOPUS. 235 at their tip; the inner ones are sty liform, distinctly longer than the outer ones and fringed upon their upper side with some few ininute light hairs; the stile-like central organ is as long as the inner appendages and is smoothly curved downwards. The coxex and the long, very slender and very glabrous feet are yellowish. The fore cox of the §& have a proportionally long, rather close and delicate whitish pubescence; in the ? there are, instead of the longer hairs, bristles of a white-yellowish coloring. The fore femora of the 4 have upon the under side near the basis, three thin yellowish bristles of decreasing length ; in the 2 there are in their stead four stout yellowish bristles. The hind femora of the % have upon the upper side near the basis a few long and very delicate white hairs, which are not present in the 9. The plain and’ slender fore tarsi are in both sexes much longer than the tibie ; they are still much longer in the % than in the ?; the first joint of all tarsi is very elongated, particularly in the % ; on the fore tarsi it is about twice as long as the following joints taken together, on the middle tarsi about three times as long, besides they are distinguished by their slenderness, and apparently complete glabrousness. The hind tarsi in both sexes are nearly as lovg as the tibie, their first joint in the $ somewhat longer than the fol- lowing joints taken together, but in the 9 somewhat shorter. Tegule on the margin with only a single quite small black dot; their cilia whitish. Wings grayish hyaline, long and narrow, towards the basis still more narrowed, particularly in the 4 ; their anterior veins are yellow, the posterior ones more infuscated ; the anterior branch of the third longitudinal vein is very long, rather flat and but little curved; the posterior transverse vein is far remote from the margin and has a very oblique position. The % possesses, as a particular distinctive mark, upon the under side of the basis of the wing, a crooked, black, rather stout thorn, in- serted near the anterior margin. Hab. Pennsylvania. (Coll. Winth.) Observation.—The P. delicatus of Mr. Walker, who described a ?, has an entirely green abdomen, can therefore not be tener, as the basis of the abdomen of its 2 is always colored with yellow. 286 DIPTERA OF NORTH AMERICA. [PART II, 2. Middle and hind coxesz blackish. 21. P. filipes Lorw. %.—Gracilis, longipes, nitidus, capite, thorace scutelloque chalybeis, abdomine viridi, proboscide, duobus primis an- tennarum articulis, coxis pedibusque flavis, femorum intermediorum basi nigra, tibiis intermediis tarsisque omnibus fuscis. Slender, long-legged, shining, head, thorax and scutellum steel-blue, ab- domen green; proboscis, the two first joints of the antennez, coxe and feet yellow, still the basis of the middle femora blackish ; middle tibie and all tarsi brown. Long. corp. 0.26. Long. al. 0.26. Syn. Psilopus filipes Lo—w, Neue Beitr. VIII, 99, 18. Of slender shape and very long-legged, shining. Head pur- plish-blue; proboscis yellow, palpi brown, both beset with minute light hairs. Face without hairs, very broad, covered with dense yellowish dust; its upper part is quite unusually convex. The two first joints of the antenne yellow, the second fringed with short minute white-yellowish hairs ; the small third joint rounded, brownish-black; arista dorsal, proportionally of insignificant length. Front without hairs, with grayish-yellow dust, which does not cover the shining purplish ground-color upon the middle ; the usual black bristles of moderate length. Thorax and scutel- lum shining purplish-blue, with a yellowish dust, which does not cover the lustre of the ground-color. The black bristles of the tho- rax rather long. The scutellum has but two bristles, still near the lateral corners, on its margin, some long hairs are inserted. . Face and front green, with white down. Antenne and arista black. Thorax and abdomen golden-green. Femora brilliant-green ; knees yellow ; tibiz fulvous; tarsi brownish-yellow ; the hind ones brown, with the first joint yellow. Wings hyaline. North America. (Collection of Mr. Hoffmeister in Nordhausen.) Page 128. No.5. Dolichopus heteroneurus. AMneo-viridis. Thorace vittis violaceis. Pedibus flavis. Alis cellula posticé prima subclausd. (Tab. 12, fig. 10.) Long. 141. Palpes noirs. Face et front larges, d’un vert noiratres, 4 léger duvet gris. Antennes: les deux premiers articles fauves ; premiér un peu allongé et menu; troisiéme ovale, assez large, noir, & base fauve ; style noir, peu allongé. Thorax d’un vert foncé, a bandes violettes. Abdomen vert; ventre a duvet blanc. Pieds jaunes, hanches antérieures noiratres; un peu de brun a l’extremité des cuisses ; tarses bruns. Ailes assez claires ; premiere cellule posté- rieure presque fermée; deuxiéme nervure transversale éloignée du coude. De l’Amérique septentrionale. (Collection de M. Hoffmeister de Nordhausen.) ( Translation.)—Golden-green. Thorax with violet stripes ; feet yellow. Wings with the first posterior cell almost closed. (Tab. 12, fig. 10.) Long. lin. one and one-half. ; Palpi black. Face and front broad, blackish-green, with a slight gray down. Antenne: two first joints fulvous: the first somewhat prolonged and slender; the third oval, rather broad, black, with fulvous basis; arista black, not very lone. Thorax dark-green, with violet stripes. Abdomen green, venter with whitish down. Feet yellow, anterior coxe blackish ; tip of femora somewhat infuscated ; tarsi brown. Wings rather hyaline ; first posterior cell almost closed ; second transverse vein at some distance from the flexure of the fourth vein. Hab. North America, 300 DIPTERA OF NORTH AMERICA. [PART EI. Walker, Insecta Saundersiana. Page 207. Psilopus lepidus Mas. ai Viridis, .abdominis segmentorum marginibus anticis nigris, antennis pedibusque nigris, alis limpidis fusco-bifasciatis. Bright-green, beset with black bristles; head blue, tinged with purple, adorned in front with white bloom; eyes bright-red ; mouth black; feelers black; sixth joint as long as the chest; chest not shining, tinged with blue; breast with 3, hoary covering ; abdomen tapering from the base to the tip, narrower and much longer than the chest; a black band on the fore border of each segment ; legs black, clothed with black hairs and bristles ; wings colorless, adorned with two dark-brown bands which are united on the fore border; tip cross-vein forming a right angle, whence it is indistinctly waving to the tip of the wing; lower cross-vein very slightly waving; wing-ribs and veins black. Length of the body two and one-half lines ; of the wings six lines. Y Mexico. | Page 211. Medeterus exustus Fem. Nigro-eneus, capite antico viridi; abdomine purpureo cupreo, antennis pedibusque nigris, femoribus eneis, alis cinereis, costa venarumque marginibus fuscis. | Allied to M. notatus. Bronze-black, beset with black bristles, which form a cross-row behind the head, adorned beneath with a whitish covering ; head green in front, clothed beneath with black hairs; peristoma prominent; eyes red; facets of the fore part rather large; feelers black; abdomen obconical, coppery with a slight purplish tinge, not longer than the chest; legs long, black, thickly clothed with black down, beset with a few black bristles ; thighs brassy, armed with black spines ; foot-cushions dark-tawny ; wings darkish-gray, very dark-brown beneath the fore border and along the borders of the veins in the disk; wing-ribs and veins black; poisers dark-tawny with pitchy knobs. Length of the body two and one-half lines; of the wings six lines. Bolton, North America. APPENDIX. 301 Page 212. Medeterus viridifiios Fru. Fulvo-viridis, thoracis disco fusco, antennis pedibusque nigris, femoribus viridibus, alis subcinereis ad costam subfuscis. Pale grassy-green, tinged with tawny above and with whitish bloom beneath, beset with a few black bristles; head brown about the eyelets, beset behind the eyes with a row of black bristles, clothed beneath with white hairs; eyes red, thickly clothed with short, white hairs; feelers black; disk of the chest brownish ; abdomen obconical, longer than the chest, clothed with very short white hairs ; legs black, clothed with very short black hairs, beset with black bristles ; thighs green, with which color the shanks are also tinged; wings slightly gray, tinged with pale-brown beneath the fore border; wing-ribs and poisers tawny ; veins black, tawny at the base. Length of the body one and one-half lines; of the wings four and one-half lines. North America. Page 212. Dolichopus bifroms Fem. Aneo-viridis, capitis vertice cyaneo, abdominis segmentorum marginibus anticis cupreis, antennis fulvis, pedibus flavis, alis subcinereis. - Green, beset with black bristles, adorned beneath with a white covering ; crown of the head blue, tinged with green and purple; an olive stripe between the feelers and the epistoma ; eyes red; mouth pitchy. Feelers tawny; third joint pitchy towards the tip ; sixth black, feathered; a brassy tinge on the chest; abdomen obconical, longer than the chest, coppery on the fore border of each segment whose sides are adorned with a white covering ; legs yellow, clothed with very short black hairs, which as usual are most frequent on the feet; thighs stout, shanks beset with black bristles ; wings very slightly gray ; wing-ribs tawny; veins black, tawny at the base, poisers yellow. Length of the body one and one-half to one and three-fourth lines; of the wings - three and one-half: to four lines. United States. 302 DIPTERA OF NORTH AMERICA. [PART 11, Page 213. Dolichopus conmsors Fem. AMneo-viridis, vertice purpureo, thorace antico cyaneo, abdominis suturis nigris, antennis pedibusque fulvis, alis subcinereis. Green, beset with black bristles, adorned beneath with a whitish covering ; crown purple; eyes black; mouth tawny; feelers tawny ; sixth joint black, feathered with much shorter hairs than those of D. bifrons; chest brassy-green, blue in front; abdomen obeonical, clothed with short, black hairs, a little longer than the chest, sutures of the segments blackish; legs tawny, clothed with very short black hairs; shanks beset with black bristles; wings grayish ; wing-ribs tawny ; veins black, tawny at the base; poisers tawny with yellow knobs. Length of the body one and one- fourth line; of the wings three lines. United States. Page 213. Dolichopus contimgsens Fem. Viridis, vertice purpureo, antennis pedibusque fulvis, alis subcinereis. , Green, beset with black bristles, adorned beneath with a whitish covering; crown purple; eyes black; mouth tawny; feelers tawny, sixth joint black, feathered like that of D. consors; abdo- men obconical, clothed with short black hairs, a little longer than the chest; legs tawny, clothed with very short black hairs; shanks beset with black bristles ; wings grayish; wing-ribs tawny ; veins black, tawny at the base; tip cross-vein less angular than that of D. consors; poisers dark-tawny. Length of the body one and one-fourth line; of the wings three lines. United States. Page 213. Dolichopus hebes Fem. /Eneus, vertice cyaneo, abdominis segmentorum marginibus posticis viridibus, antennis pedibusque fulvis, alis cinereis costa venarumque marginibus fuscis. Brassy, beset with black bristles, adorned beneath with a whitish covering; crown of the head blue; eyes red; feelers tawny, sixth joint black, feathered with very short hairs; abdo- men obconical, longer than the chest; hind borders of the seg- ments green; legs dark-tawny, clothed with very short black APPENDIX, 303 hairs; shanks beset with black bristles; wings gray, brown beneath the fore border, and along the borders of the veins; wirg:- ribs and veins black; poisers tawny with pitchy knobs. Length of the body one and one-fourth line; of the wings three lines. United States. Page 214. Dolichopus ineptus Fem. Mneus, vertice purpureo, abdominis lateribus albo maculatis, apice viridi, antennis pedibusque fulvis, tarsis subpiceis, alis cinereis fusco vittatis. Brassy, beset with black bristles, adorned beneath with a whitish covering ; crown purple; eyes red; feelers tawny, sixth joint black, feathered with moderately long hairs; abdomen obconical, longer than the chest, green at the tip; a white spot on each side of every segment; legs dark-tawny, clothed with very short black hairs; shanks beset with black bristles; feet almost pitchy; wings gray, tinged with brown along the third and fourth longitudinal veins; wing-ribs tawny; veins black ; poisers tawny, with ferruginous knobs. Length of the body one and one-fourth line; of the wings three lines. United States. Page 214. Dolichopus maculipes Fem. Aeneo-viridis purpureo varius, antennis fulvis apice piceis, pedibus fulvis, tibiis nigro maculatis, tarsis piceis, alis cinereis costé nervorumque marginibus fuscis. Brassy-green, beset with black bristles, adorned beneath with a whitish covering; crown adorned with blue and purple; eyes red; feelers tawny; third joint pitchy; sixth black, feathered with moderately long hairs; disk of the chest partly purple; abdomen obconical, a little longer than the chest, clothed with short black hairs; legs tawny, clothed with very short black hairs; shanks beset with black bristles; feet almost pitchy; a black spot on the tip of each thigh; five or six black spots on each shank, these spots are most distinct on the hind legs; wings gray, brown beneath the fore border and along the borders of the veins ; wing-ribs and poisers tawny ; veins black. Length of the body one and one-half line; of the wings three and one-half lines. United States. 304 DIPTERA OF NORTH AMERICA. [PART II. Page 215. Dolichopus pulcher, Mas. et Fem. Cyaneo-viridis, antennis nigris, femoribus viridibus, tibiis ful- vis, tarsis piceis apice nigris, alis limpidis. Bright green with a bluish tint, beset with black bristles, adorned beneath with a whitish covering ; eyes bright red ; feelers black; sixth joint bare; abdomen of the male cylindrical, of the female obconical, clothed with short black hairs, a little longer than the chest ; scales of the male white, bordered with black ; legs tawny, clothed with very short black hairs; thighs green; shanks beset with black bristles; feet pitchy, black towards the tips; trochanters of the male yellow, of the female tawny; wings colorless ; wing-ribs tawny ; veins black; fourth longitudinal vein not as usual converging to the third after its curve, but almost parallel to it; poisers yellow. Length of the body 14 line; of the wings 3 lines. United States. Page 215. Dolichopus varius, Fem. AMneo-viridis cyaneo varius, abdomine fasciis albidis ornato, antennis pedibusque fulvis, tarsis nigris, alis cinereis, costé macu- lisque quinque fuscis. Brassy-green, tinged with blue, beset with black bristles, adorned beneath with a whitish covering; eyes red; feelers tawny ; sixth joint black, feathered with moderately long hairs; abdomen obconical, longer than the chest, adorned with bands of whitish hue; legs dark tawny; clothed with short black hairs; shanks beset with black bristles; feet black; wings gray, brown beneath the fore border, adorned with four or five brown spots; wing-ribs pitchy ; veins black; poisers tawny. Length of the body 1} line, of the wings 3 lines. United States. Walker, List of Dipterous Insects in the Collection of the British Museum, Part LI. Page 645. Psilopus delicatus, n. s., Fem. Viridis, gracilis, abdomine aureo-viridi, antennis fulvis, articulo tertio nigro, pedibus flavis, alis limpidis. Body slender, bright green, clothed with black hairs and bris- APPENDIX. 399 tles; crown of the head blue; eyes bright red; mouth yellow; feelers tawny; third joint black; bristle black, shorter than the chest ; abdomen golden-green ; legs pale yellow, long and slender, clothed with short black hairs ; feet pitchy towards the tips ; wings colorless ; wing-ribs and poisers tawny ; veins pitchy. Length of the body 24 lines, of the wings 5 lines. a. New York. Presented by the Entomological Club. b. New York. Presented by E. Doubleday, Esq. Page 646. Psilopus gemmiifer, n. s., Mas. Viridis, cyaneo purpureoque varius, antennis nigris, pedibus flavis, alis limpidis, cost&é apicem versus nervisque transversis fusco-nebulosis. Body bright green, beset with black hairs and bristles; head covered in front with silvery down; eyes red; mouth tawny; feelers black, as long as the head and the chest, disk of the chest bluish-green, tinged with purple; scutcheon purple; sides and breast covered with silvery bloom; abdomen slender; tip bluish purple; appendages dark tawny; legs yellow, beset with black hairs and bristles, which are most thick on the feet; four hinder hips green ; thighs clothed with white hairs ; feet towards the tips and hind feet pitchy; wings colorless, clouded with pale brown towards the tips of the fore borders and along the cross-veins ; wing-ribs tawny; veins black; poisers tawny. Length of the body 24 lines, of the wings 5% lines. a. Trenton Falls. Presented by E. Doubleday, Esq. Page 646. Psilopus chrysoprasi, n. s. Aureo-viridis, capitis vertice purpureo-cyaneo, scutello abdo- minisque basi purpureis, abdominis segmentorum suturis sneo- purpureis, antennis nigris, pedibus piceis, femoribus viridibus, | tibiis anterioribus tarsisque anticis fulvis, alis subcinereis. Body golden-green, beset with black bristles; head purplish- blue on the crown, slightly covered with white down in front ; eyes bright red; mouth and feelers black ; scutcheon purple; ab- domen adorned with purple towards the base ; sutures of the seg- ments brassy-purple ; legs pitchy, thickly clothed with short black hairs; hips and thighs green; hips slightly covered: with white bloom, thighs fringed with white hairs; fore shanks pale tawny ; middle shanks and fore feet dark tawny; wings slightly gray ; 20 306 DIPTERA OF NORTH AMERICA. [PART I. wing-ribs and poisers pitchy ; veins black. Length of the body 2 lines, of the wings 44 lines. a. West Indies. From Mr. Children’s collection. Page 648. Psilopus suavium, n. s. Viridis, capitis vertice cyaneo-purpureo, abdomine apicem ver- sus purpureo, antennis pedibusque nigris, femoribus viridibus, alis limpidis, fusco bifasciatis. } Body bright green, beset with black bristles; head bluish-pur- ple on the crown, clothed with white down in front; eyes red; mouth pitchy ; feelers black; bristle nearly as long as the chest ; breast and sides of the chest covered with a white bloom; abdo- men purple towards the tip ; legs black, beset with black hairs and bristles; hips and thighs green ; hips covered with a white bloom; thighs clothed with white hairs ; wings colorless, adorned with two brown bands, which are joined together on the fore border and more slightly on the disk, but do not reach the hind border nor the tip; veins black; wing-ribs and poisers pitchy. Length of the body 24 lines, of the wings 5 lines. a. Jamaica. From Mr. Grosse’s collection. Page 648. Psilopus amatus, n. s., Mas. et Fem. Viridis, capite purpureo, abdomine nigro-fasciato apice pur- pureo, antennis nigris, pedibus piceis, femoribus viridibus, alis sub- cinereis, costé apicem versus nervisque transversis fusco nebulosis. Body bright green, beset with black hairs and bristles; head purple, covered in front with white down; crown of the male adorned with a green spot on each side; eyes red; mouth and feelers black; bristle a little shorter than the chest; hind part of the chest tinged with blue and purple; sides and breast covered with white down; abdomen at the tip purple in the male, bluish- purple in the female; hind borders of the segments in the male adorned with black bands; legs pitchy, beset with black hairs and bristles; hips and thighs green, the former covered with white down; wings slightly gray, indistinctly marked with brown towards the tips of the fore borders and along the cross-veins; wing-ribs pitchy ; veins black; poisers of the male pitchy, of the female tawny. Length of the body 15—1? line, of the wings 33—4 lines. a. New York. Presented by E: Doubleday, Esq. b. Trenton Falls. Presented by E. Doubleday, Esq. APPENDIX. 307 Page 649. Psilopus inficitus, n. s. Viridis, capite purpureo, abdomine purpureo,* abdomine pur- pureo-cyaneo, fasciis nigris, antennis pedibusque nigris, alis sub- cinereis fusco bifasciatis. Head and chest beset with black bristles ; head purple, fringed about the mouth with hoary hairs; eyes red; mouth and feelers black; bristle a little longer than the chest; chest green; sides and breast covered with whitish down; abdomen deep purplish- blue; sutures, of the segments black; legs black, clothed with black hairs and bristles; wings slightly gray, adorned with two brown bands, which are united on the fore border, but do not reach the hind border; wing-ribs and veins black; poisers pitchy, with-tawny knobs. Length of the body 25 lines, of the wings 5 lines. a. Mexico. Presented by E. P. Coffin, Esq. Page 650. Psilopus nigrofemoratus, MSS. Cyaneo-, aut aureo-viridis, antennis nigris, capite duplo longi- oribus, pedibus nigris tibiis fulvis, alis limpidis. Head and chest bright bluish-green, armed with black bristles; head covered in front with white down, clothed beneath with white hairs; eyes red; mouth tawny ; feelers black, about twice the length of the head; breast and under side of the abdomen covered with white bloom ; abdomen golden-green, blue at the base, coppery at the tip; legs black, beset with a few black bristles ; shanks tawny, with black tips; wings colorless; wing-ribs tawny; veins black ; poisers yellow. Length of the body 1j line, of the wings 24 lines. Var. 6. Chest golden-green, bluish-green behind; abdomen coppery-green; tips of the thighs and the whole of the shanks tawny. Var. y. Abdomen bright green or bluish-green ; a bronze band on the fore border of each segment. a. North America. Presented by the Entomological Club. b. Nova Scotia. From Lieut. Redman’s collection. Page 651. Psilopus albicoxa Mas. et Fem. Cyaneo-, aut cupreo-viridis, antennis nigris, capite duple longi- oribus, pedibus flavis, tarsis posticis nigris, alis subcinereis. Head and chest armed with black bristles; head bluish-green, * Evidently a misprint in the original. 398 DIPTERA OF NORTH AMERICA. [PART IT. covered in front with white down, clothed beneath with white hairs ; eyes red; mouth tawny; feelers black, about twice the length of the head; palpi black; chest of the male bluish-green, sometimes black towards the tip, of the female bright green or ecoppery-green ; sutures of the segments sometimes black ; breast and under side of the abdomen covered with white down; legs yellow, adorned with rows of minute spines, clothed with a few white hairs, and beset with a few black bristles; four hinder hips green; tips of feet black; hind feet black, first joint brownish; wings slightly gray, wing-ribs tawny; veins black; poisers yellow. Length of the body 14 line; of the wings 23 lines. a. North America. Presented by the Entomological Club. b. Ohio. Presented by the Entomological Club. c. Massachusetts. From Prof. Sheppard’s collection. d. Nova Scotia. From Lieut. Redman’s collection. Page 651. Chrysotus incertus, n. s. Viridis, antennis nigris, femoribus viridibus, tibiis fulvis, apice tarsisque obscurioribus, alis limpidis. Allied to C. femoralis. Body green, beset, with black hairs and bristles; eyes red; mouth and feelers black; hips and thighs green ; shanks tawny ; feet and tips of shanks dark tawny ; wings colorless; wing-ribs pitchy ; veins black; poisers tawny. a. United States. Presented by the Entomological Club. Page 653. Porphyrops pilosicormis, Barysron’s MSS. AMneo-viridis, antennis nigris, pedibus fulvis, tarsis piceis, femoribus posticis apice fusco maculatis, alis limpidis. Body brassy-green, beset with black bristles; eyes dark-red; mouth dark tawny; feelers black; bristle downy, proceeding from the base of the third joint and more than twice its length; breast and sides of the chest covered with a white bloom, which appears also on the chest, but is there very slight; legs tawny, clothed with short black hair, beset with afew black bristles ; feet pitchy ; a small brown mark on the tip of each hind thigh; fore hips at the bage and the other hips green and covered with white bloom ; wings colorless; wing-ribs tawny; veins black; poisers yellow. Length of the body 14 line; of the wings 25 lines. a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Hsq. APPENDIX. 309 Page 655. Medeterus slaber, Barnysron’s MSS. Viridis, thoracis disco nigro-zneo, abdomine zeneo-viridi, anten- nis nigris, pedibus. viridibus, tarsis nigris, alis cinereis, fusco bima-~' culatis. Body green ; head and chest beset with a few black hairs; head covered with white bloom in the male, with golden bloom in the female; eyes red; mouth and feelers black; disk of the chest bronze-black ; sides covered with tawny bloom; breast covered with white bloom; abdomen brassy-green, covered above with short tawny hairs; under side covered with white bloom; legs bright green, rather stout, clothed with short black hairs and bristles ; hips covered with white bloom ; feet black ; wings gray ; each ‘with two small brown spots, one on the cross-vein, the other on the fourth longitudinal vein, a little before half the distance between the cross-vein and the tip of the wing; wing-ribs pitchy ; veins black; poisers tawny. Length of the body 12 line; of the wings 5 lines. a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Esq. ; Page 655. Miedeterus chrysologus, Barnston’s MSS., Fem. Nigro-neus, antennis nigris, pedibus viridibus, tarsis nigris, alis cinereis, fusco bimaculatis, ad costam subfuscis. Body brassy black; head covered with golden bloom, which is paler and brighter towards the mouth ; eyes dark-red, covered with white down; mouth and feelers black; sides of the chest covered with tawny bloom ; breast and under side of the abdomen adorned with white bloom; a row of black punctures on each side of the abdomen, as in other species; legs green, clothed with black hairs and bristles; hips and thighs covered with white bloom; feet black; wings gray, brown along the fore borders, each with two darker brown spots, like those of JZ glaber, but larger and more distinct; wing-ribs tawny; veins black; poisers pitchy. Length of the body 1j line; of the wings 3 lines. a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Esq. 310 DIPTERA OF NORTH AMERICA. [PART IT. Page 656. Medeterus albofflorens, n. s., Fem. AMneus, fulvo pubescens, subtus albus, abdomine cupreo-viridi, antennis nigris, pedibus viridibus, tarsis piceis, alis cinereis fusco subvittatis. | Head and chest bronzed, beset with a few black bristles, thickly covered with tawny bloom; eyes dark red, covered with white down; mouth and feelers black; abdomen rather light green, mingled with copper-color, thinly clothed with short black hairs, not longer than the chest ; hind chest, breast, and under side of the abdomen covered with white bloom; legs long, slender, green, slightly covered with tawny bloom, -beset with short black hairs and bristles ; feet pitchy towards the tips; claws black ; foot-cushions pale yellow; wings gray, very slightly clouded with brown along the borders of the veins; wing-ribs pitchy ; veins black; poisers tawny, pitchy, and covered with white bloom towards the tips. Length of the body 13-14 line; of the wings 444 lines. a. Nova Scotia. From Lieut. Redman’s collection. Page 659. Dolichopus affimis, Haumay’s MSS., Mas. et Fem. Cyaneo-, aut cupreo-viridis, antennis nigris, pedibus flavis, femo- ribus posticis tarsisque fulvis, tarsis anticis, marz. apice nigris dilatatis, tarsis posticis nigris, alis limpidis. Male.—Head and chest green, armed with stout black bristles ; head fringed behind with pale tawny hairs, covered in front and beneath with white bloom; eyes red, covered with white down; feelers black; chest bluish-green on the disk ; abdomen coppery- green, clothed with short black hairs, covered with white bloom beneath and on each side, where there is a row of black punctures; appendages pale yellow; legs yellow, clothed with short black hairs ; four hinder hips green; hind thighs tawny, furnished-with a few tawny hairs; shanks and feet armed with black bristles ; feet tawny, darker towards the tips; hind feet black; tips of fore feet black, widened ; wings colorless ; wing-ribs and poisers yel- low ; veins pitchy. Female.— Body coppery-green; legs tawny; shanks darker than the thighs ; hind feet pitchy. Length of the body 2-24 lines; of the wings 4—5 lines. a. Nova Scotia. From Lieut. Redman’s collection. APPENDIX. Slt Page 660. Dolichopus cuprinus? Wrp., Auss. Zweif. ii, 230, 1. D. cupreus? Say, Journ. Acad., Phila., iii. 8, 6. Aureo-viridis, thorace vittis tribus cupreis, antennis fulvis apice fuscis, pedibus flavis, tarsis apice nigris, anticis apice nigro-fasci- culatis, alis subcinereis. Body green, covered above with golden down, beneath with white down; head and chest armed with stout black bristles ; hind part of the head fringed with white hairs; eyes red; mouth yellow ; feelers tawny, covered with short black hairs; their tips brown; bristle pubescent, pitchy, longer than the rest of the feelers; chest adorned with three coppery stripes; abdomen olden green, clothed with short black hairs, white beneath and on each side, where it has a row of black punctures; appendages yellow ; legs yellow, clothed with black hairs; four hinder hips green; feet towards the base and shanks armed with black bristles ; four hinder feet black towards the tips; tips of fore feet adorned with tufts of black hairs; wings slightly gray ; wing-ribs tawny ; veins pitchy ; poisers yellow. Length of the body 24 lines; of the wings 5 lines. a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Esq. 7 Page 660. Dolichopus lamellipes, Barnston’s MSS., Mas. et Fem. Viridis aut viridi-cupreus, abdomine subtus albo-pubescente, antennis nigris basi rufis, articulo tertio mari. longo, pedibus fulvis, tarsis nigris, intermediis basi fulvis, anticis marv. apice dilatatis, alis limpidis. Body green; head and chest armed with black bristles; head covered with silvery down, fringed behind with black hairs ; eyes red; mouth tawny ; feelers black ; first joint pale red; third joint very long; abdomen clothed with black hairs, adorned with a coppery tinge towards the tip, which is black, covered with white bloom beneath and on each side, where there is a row of black punctures ; legs pale tawny, four hinder hips green, clothed with black hairs and bristles; feet black; tips of fore feet widened; middle feet tawny towards the base; wings colorless; wing-ribs tawny ; veins pitchy; poisers pale tawny. Female.—Third joint of the feelers short, nearly round. Length of the body 25-3 lines; of the wings 5 lines. 312 DIPTERA OF NORTH ‘AMERICA. [PART ae Var. 6. Chest and abdomen coppery. a. St. Martin’s Falls, Albany River, Hudson’s eae Presented by G. Barnston, Esq. Page 661. Dolichopus ciliatus, Barnsron’s MSS., Mas. et Fem. Viridis, capitis fronte aureo-pubescente, antennis fulvis, arti- culo 8° supra nigro, pedibus fulvis, tarsis piceis alis subcinereis. Body green ; head covered in front with golden down; eyes red; mouth black; feelers tawny; third joint nearly oval, black from near the base to the tip above, and from half its length to the tip beneath ; bristle black; breast and sides of the chest and of the abdomen covered with white bloom; appendages of the abdomen tawny; scales white; legs tawny; feet pitchy; fore feet dark tawny; wings slightly gray; wing-ribs tawny; veins black; poisers yellow. Length of the body 1-1? line; of the wings 3 lines. a. St. Martin’s Falls, Albany Raver Hudson’s Bay. Presented by G. Barnston, Esq. Page 661. Dolichopus adjacems, n. s., Fem. AMneus viridi varius, capite cyaneo-viridi, antennis nigris, pedi- bus fulvis, tarsis posticis piceis, alis subcinereis. Head bluish-green on the crown, covered in front with yellowish white down, fringed along the eyes with hoary hairs; eyes red; mouth pitchy ; palpi tawny ; feelers black ; third joint very short; chest and abdomen brassy, mingled with green; breast and sides of the chest covered with gray bloom, which also appears beneath the abdomen, but is more slight; legs tawny ; hips green, covered with gray bloom; fore hips mostly tawny; feet darker than the shanks, especially towards the tips; hind feet pitchy; wings slightly gray ; wing-ribs and poisers tawny ; veins black. Length of the body 8 lines; of the wings 6 lines. a. St. Martin’s Falls, Albany River, Hudson’s em Presented by G. Barnston, Esq. Page 661. Dolichopus coercems, n. s., Mas. Viridis, capite cyaneo-viridi, thoracis lateribus cupreo et cyanco ornatis, abdomine cupreo vario, apice nigro, antennis nigris, pedi- bus fulvis, alis limpidis. APPENDIX. o13 Head bluish-green, covered in front with pale tawny down, fringed along the eyes with white hairs; eyes bright red; mouth pitchy ; feelers black ; third joint very short ; chest green, slightly tinged on each side with blue and copper color; disk sometimes bluish-green ; breast covered with hoary down; abdomen green, with a coppery tinge here and there; tip black; appendages pale tawny; scales white, bordered with black; legs tawny; hips, towards the base, green, and covered with a white bloom ; shanks beset with black bristles; feet pitchy towards the tips; fore feet slender, pale tawny ; their tips black, and much widened ; wings colorless ; wing-ribs and poiser tawny; veins black. Length of the body 3 lines; of the wings 54 lines. a. New York. Presented by the Entomological Club. Page 662. Dolichopus fimitus, n. s., Mas. Viridis, thoracis lateribus abdomineque cupreo variis, hujus lateribus basi cyaneo-viridibus, antennis nigris, pedibus fulvis, tarsis apice nigris, tarsis anticis apice latis, tarsis posticis nigris, alis subcinereis. 3 Body ereen ; head covered in front with white down; fringed along the eyes with white hairs; eyes red; mouth pitchy; palpi tawny ; feelers black ; third joint rather large; chest with a slight coppery tinge on each side, which, like the breast, is slightly covered with hoary bloom; abdomen tinged with coppery color, and with a slight blue hue on each side towards the base ; append- ages at the tip tawny; scales white, bordered with black; legs tawny, middle feet towards the tips, and hind feet, excepting the base, black ; tips of fore feet black and somewhat widened; wings slightly gray, wing-ribs and poisers tawny; veins pitchy. Fem.— Feet black, tawny at the base. Length of the body 3 lines; of the wings 5 lines. a. New York. Presented by the Entomological Club. Page 662. Dolichopus distractus, n.'s. Viridis, abdomine cupreo, antennis nigris, articulo 1° subtus fulvo, pedibus fulvis, tarsis apice piceis, alis subcinereis. Body green; head covered in front with white down, clothed on each side of the eyes with white hairs; eyes bright red; feelers black; first joint tawny beneath; third joint short and broad; 314 DIPTERA OF NORTH AMERICA. [ PART II. abdomen copper colored; legs tawny; feet pitchy towards the tips; wings slightly gray; wing-ribs and poisers tawny; veins black. Length of the body 24 lines; of the wings 5 lines. a. New York. Presented by EH. Doubleday, Esq. Page 662. Dolichopus discessus, n. s., Fem. Cyaneo-viridis, thorace cupreo bivittato, abdomine eneo-viridi, antennis pedibusque fulvis, tarsis posticis piceis, alis subcinereis. Body bluish-green ; head covered in front with white down; eyes bright red; mouth and feelers tawny; bristle black; chest adorned with two bright copper-colored stripes; sides and breast covered with white bloom ; abdomen green, brassy here and there, especially towards the tip; sides and under side covered with white down; legs tawny; tips of feet and hind feet, except the base, pitchy ; wings slightly gray ; wing-ribs and poisers tawny ; veins black. Length of the body 24 lines; of the wings 54 lines. a. Massachusetts. From Prof. Sheppard’s collection. Page 663. Dolichopus comtiguus, n. s., Mas. Aureo-viridis, thorace viridi-cyaneo, lateribns purpureo variis, abdomine cyaneo et cupreo vario, antennis nigris, pedibus fulvis, tarsis anticis apice nigris latis, tarsis mediis piceis, basi fulvis, tarsis posticis nigris, alis limpidis. Head golden-green, covered in front with pale tawny down; eyes bright red; feelers black; third joint oval; chest greenish- blue, with a slight purple tinge on each side; abdomen golden- green, Slightly bluish and coppery here and there; breast and under side of the abdomen covered with hoary bloom; tip black ; appendages tawny, scales whitish; legs tawny; four hinder hips mostly green, and tinged with hoary bloom; tips of fore feet black, much widened ; middle feet pitchy, tawny at the base; hind feet black; wings colorless; wing-ribs and poisers tawny; veins pitchy, tawny towards the base. Length of the body 2 lines; of the wings 4 lines. a. New York. Presented by the Entomological Club. Page 663. Dolichopus exclusus, n. s., Fem. Cupreus, nonnunquam viridi varius, abdomine purpureo-cupreo, antennis nigris, articulo primo subtus fulvo, pedibus fulvis, tarsis nigris, alis subcinereis. APPENDIX. 315 Body coppery, sometimes varied with green; head covered in front with white bloom; eyes red; mouth pitchy; palpi tawny ; feelers black ; first joint tawny beneath ; third joint oval, as long as the first and the second; breast covered with gray bloom ; abdomen purplish copper-color, covered beneath with gray bloom ; legs tawny; hips coppery; fore hips mostly tawny; feet black ; wings slightly gray ; wing-ribs tawny; veins black; poisers pale tawny. Length of the body 2 lines; of the wings 44 lines. _ a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Esq. Page 664. Dolichopus confinis, n.s., Fem. Afneus, viridi varius, capite viridi, antennis nigris, pedibus fulvis, tarsis piceis, tibiis posticis apice tarsisque posticis nigris, alis cinereis. Body brassy, mingled here and there with green; head green, covered in front with white down, clothed along the sides of the eyes with white hairs; eyes red; mouth pitchy; feelers black; third joint nearly oval, rather short; breast covered with white bloom; legs tawny; feet pitchy, tawny towards the base; hind feet and tips of hind shanks black; wings gray; wing-ribs and poisers tawny; veins black. Length of the body 2 lines; of the wings 4 lines. a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Esq. Page 664. Dolichopus conterminus, 1. s., Mas. Viridis, thoracis disco abdomineque aureo-viridibus, hujus apice eneo, antennis nigris, pedibus fulvis, tarsis anticis apice nigris latis, tarsis mediis apice posticisque piceis, alis limpidis, fem. tarsis piceis basi fulvis, tarsis posticis nigris. Body bright green; head covered with tawny down, fringed along the sides of the eyes with white hairs; eyes bright red, eovered with white down; mouth pitchy; palpi tawny; feelers black ; third joint rather large; abdomen and disk of the chest golden-green; breast and sides of- the chest covered with hoary bloom, which also slightly tinges the under side of the abdomen ; tip of the abdomen brassy ; appendages tawny; scales white, slightly bordered with black; legs pale bright tawny; four hind hips mostly green, and covered with a white bloom ; thighs fringed ° 316 DIPTERA OF NORTH AMERICA. [PART II. with white hairs, fore feet slender, with black and much widened tips ; middle feet pitchy towards the tips; hind feet pitchy ; wing colorless; wing-ribs tawny; veins black; poisers pale tawny. Fem.—Feet pitchy, tawny towards the base; hind feet black. Length of the body 2 lines; of the wings 4 lines. a. New York. Presented by E. Doubleday, Esq. b. North America. Presented by the Entomological Club. Page 665. Dolichopus separatus, n. s., Fem. Viridis, abdominis apice cupreo, antennis fulvis, articulo tertio apice nigro, pedibus fulvis, tarsis nigris, alis subcinereis. Body green; head covered in front with tawny down; eyes red; mouth pitchy; palpi tawny; feelers tawny; third joint oval, black towards the tip; bristle black; breast, sides of the chest and under side of the abdomen covered with white bloom ; abdomen coppery towards the tip; legs tawny; four hind hips green, covered with white bloom; feet black ; wings slightly gray; wing- ribs and poisers tawny; veins pipck. dnote of the body 2 lines ; of the wings 4 lines. a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Esq. Page 665. Dolichopus terminatus, n. s., Fem. Aureo-viridis, capite cyaneo-viridi, abdomine cupreo basi viridi, antennis nigris, pedibus fulvis, tarsis piceis basi fulvis, alis sub- cinereis fusco subvittatis. Head bluish-green, covered in front with golden down, fringed on each side with white hairs; eyes bright red; mouth pitchy ; palpi tawny ; feelers black; third joint nearly oval; chest golden- green; sides and breast covered with hoary bloom, which also appears beneath the abdomen; abdomen copper-color, green at the base; legs tawny; four hind hips green, covered with white bloom ; feet pitchy, tawny towards the base; wings slightly gray, indistinctly tinged with brown along the borders of the veins; wing-ribs and poisers tawny; veins pitchy. Length of the body 2 lines; of the wings 4 lines. a, midnth America. Presented by the Entomological Club. APPENDIX. 817 Page 666. Dolichopus sequax, n. s. Cyaneo-viridis, thorace eneo-viridi, abdominis apice neo, an- tennis fulvis, articulo tertio nigro subtus fulvo, pedibus fulvis, tarsis nigris anticis piceis, alis limpidis. Body bluish-green ; head covered in front with golden down ; eyes red; mouth pitchy; feelers tawny; third joint black, tawny beneath towards the base; bristle black; chest with a slight brassy tinge; breast covered with a hoary bloom; abdomen bluish-green; tip bronzed; appendages tawny; scales white, with dark borders, under side slightly covered with hoary bloom ; legs tawny, feet black; four hind hips mostly green, covered with white down ; middle shanks -with a slight tuft of black hairs at the base ; fore feet pitchy, tawny at the base; wings colorless; wing- ribs and poisers tawny; veins black. Length of the body 13 line; of the wings 3 lines. . a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Esq. Page 666. Dolichopus soccatus, Baryston’s MSS. AMneus, capite viridi, abdomine cupreo basi viridi, antennis fulvis, articulo tertio nigro subtus fulvo, pedibus fulvis, tarsis nigris, alis subcinereis. Head green, covered in front with hoary down, fringed along the eyes with whitish hairs; eyes red; mouth tawny; feelers tawny ; third joint black, very short, tawny beneath till near the tip; bristle black; chest brassy; sides and breast covered with hoary bloom; abdomen coppery, green at the base; legs tawny ; feet black; wings slightly gray ; wing-ribs tawny; veins black ; poisers yellow. Length of the body 1? line; of the wings 34 lines. ' Var. 8. Body brassy, tinged with green. a. St. Martin’s Falls, Albany River, Hudson’s Bay. Presented by G. Barnston, Esq. Page 666. Dolichopus remotus, n. s. Aineo-viridis, capite thoracisque lateribus eyaneo-viridibus, ab- domine basi viridi, antennis nigris, pedibus fulvis, tibiis posticis apice tarsisque posticis nigris, alis limpidis. . 318 DIPTERA OF NORTH AMERICA. [PART IT. Head bluish-green, clothed in front with white down; fringed on each side with white hairs; eyes red; feelers black; chest brassy green, bluish-green on each side; breast covered with hoary bloom; abdomen brassy, green at the base, tinged with ereen on each side, covered with white bloom beneath ; tip black; appendages tawny; scales white, bordered with black; legs tawny; tips of feet pitchy; hind feet and tips of hind shanks black; wings colorless; wing-ribs and poisers pale tawny; veins black. Length of the body 14 line; of the wings 8 lines. a. North America. Presented by the Entomological Club. Page 667. Dolichopus irrasus, s. n., Fem. Cyaneus, abdomine neo, antennis nigris, pedibus fulvis, tarsis piceis, alis cinereis fusco subvittatis. ; Body deep blue, beset with black hairs and bristles; head covered in front with a silvery bloom; eyes red; mouth and feelers black; chest covered with ferruginous bloom; sides and chest covered with white bloom; abdomen dark bronze, slightly covered with white bloom, not longer than the chest; legs tawny, clothed with black hairs and bristles; feet pitchy; wings gray, brownish along the borders of the veins; wing-ribs and veins black; fourth longitudinal vein slightly bent ; poisers dark tawny. Length of the body 1 line; of the wings 2 lines. a. Florida. Presented by EH. Doubleday, Esq. Page 667. Orthochile derempta, n. 5s. Viridis, thoracis disco cupreo, abdomine purpureo, basi apiceque cyaneo-viridi, lateribus aureo-viridibus, antennis nigris, pedibus fulvis, femoribus viridibus, alis subcineris. Body green; head and chest beset with black bristles; eyes and mouth black; feelers black; third joint very short, round ; bristle proceeding from its tip; disk of the chest copper-colored ; abdomen purple, clothed with black hairs, bluish-green at the base and at the tip, golden-green along each side; legs tawny, clothed with short black hairs; hips and thighs green; wings slightly gray; wing-ribs and poisers tawny; veins pitchy. Length of the body 14 line; of the wings 3 lines. a. North America. Presented by the Entomological Club. APPENDIX. 319 Walker, in the Transactions of the Entomological Society, Tom. IV. Page 149. Psilopus ungulivena. Mas.—Leete viridis, antennis nigris thorace longioribus, thorace subcyanescente, abdomine subaurato, pedibus testaceis, alis sub- cinereis, venis nigris. . . Male.—Bright green; antenne black, much longer than the thorax; thorax slightly bluish; abdomen somewhat gilded; legs testaceous, long, slender; wings grayish; veins black, fore-branch of the prebrachial vein very much bent, nearly rectangular ; discal transverse vein very deeply undulating. Length of the body 44 lines; of the wings 7 lines. United States. Walker, in the Transactions of the Entomological Society Tom. V. Page 287. Psilopus solidus. Fom.—Cyaneo-viridis, robustus, subtus albido-tomentosus, an- tennis pedibusque nigris, abdominis lateribus basi cupreis, alis subcinereis, fasciis duabus (1° media lata, 2* apicali latissima) nigris antice connexis, halteribus testaceis. Female.—Bright bluish-green, stout, with whitish tomentum beneath; antennz and legs black; abdomen bright cupreous on each side at the base; wings slightly grayish, with a broad black band in the middle and a very broad apical black band, the two bands connected in front; fore branch of the prebrachial vein almost rectangular; discal transverse vein straight, oblique; halteres dull testaceous. Length of the body 3 lines; of the wings 7 lines. Mexico. Page 287. Psilopus peractus. Fom.— Viridis, robustus, subtus albido-tomentosus, capite cyaneo, antennis, pedibus halteribusque nigris, abdomine neo- viridi, alis subcinereis, venis nigris. ’ Female.—Green, stout, with whitish tomentum beneath; head blue; antennee and legs black; abdomen eneous-green; wings ‘ 320 DIPTERA OF NORTH AMERICA. [PART II. grayish ; veins black ; fore-branch of the prebrachial.vein obtusely rectangular; discal transverse vein oblique, almost straight; hal- teres black. Length of the HOG 24 lines; of the wings 4 lines. Mexico. Page 287. Psilopus hereticus. Foem.—Purpureo-niger, latus, nitens, subtus albido-tomentosus, capite, antennis pedibusque nigris, abdomine nigricante purpureo, alis subcinereis, venis nigris. Female.—Purplish-black, broad, shining, with whitish iia tum beneath; head, antenne and legs black, the latter rather stout; thorax rather thickly beset with black bristles; abdomen blackish-purple; wings slightly grayish; veins black ; fore-branch of the prebrachial vein rectangular, but with the angle somewhat rounded ; discal transverse vein oblique, nearly straight. Length of the body 12 line; of the wings 34 lines. Mexico. Page 288. Psilopus permodicus. Mas.—Aureo-viridis, gracillimus, antennis pedibusque flaves- cente albis, alis limpidis, venis halteribusque pallidis. Male.—Golden-green, very slender; antenne and legs yellowish- white; wings limpid; veins pale; fore-branch of the prebrachial vein obtusely rectangular; discal transverse vein oblique, sttaight ; halteres very pale. Length of the body 12 line; of the wings 4 lines. Mexico. SUPPLEMENT TO THE MONOGRAPH ON NORTH AMERICAN DOLICHOPODIDA:* I, General Remarks on the Dolichopodide of North America. THat the North American fauna of Dolichopodide is an ex- ceedingly rich one, is proved by that portion of it upon which I have based the present publication. I am satisfied that this fauna far exceeds the European fauna in the variety of forms and in the number of species. I take the following points to be peculiar to this fauna: 1. The apparently rather numerous species of Pelastoneurus; 2. The re- markable abundance of closely allied species of true Gymnopter- nus; 3. The number of species of Chrysotus distinguished by a variety of plastic characters, which is not generally the case in this genus; 4. The abundance of species of Diaphorus and of forms related to this genus. Our knowledge of the genera occur- ring in North America is too limited, yet, to indicate the absence of some of them as being peculiar to the fauna. A very striking circumstance connected with the North Ameri- can fauna of Dolichopodide is, that precisely in those points which we have just enumerated as peculiar to it, this fauna shows the most remarkable analogy to the remains of the fossil fauna of the same family preserved in amber. In both, there is the same abundance of species of genuine Gymnopiernus, difficult to dis- ' The volume had already gone through the press when the present sup- plement was sent in by Mr. Loew. It contains descriptions of the new species discovered mostly by me during the summer 1863. The General Remarks, prefixed to this Supplement, ferm an important addition to the preface of this volume (page iii—vi). es. 21 ( 321 ) 322 DIPTERA OF NORTH AMERICA. [PART 108 tinguish on account of their close resemblance; in both, the same frequence of species of Chrysotus, and not only the same variety of plastic specific characters among them, but even a most strik- ing conformity in the nature of these characters; in both, nume- rous species of Diaphorus and of forms related to them. A cer- tain coincidence is even perceptible among those genera, which hitherto are not represented either in the North American or in the amber-fauna. It must be added, however, that the latter shows nothing like the great abundance of the North American fauna in species of genuine Dolichopus. It would be difficult at present to make any satisfactory state- ment as to the relation in which the North American fauna of Dolichopodide stands to that of any other zoological province, as, with the exception of the Huropean fauna, our knowledge of other faunas is not sufficient for this purpose. From what we know, however, we distinctly perceive that the North American fauna closely approaches the European and the North Asiatic faune in the species of the genera Hygroceleuthus, Dolichopus, Tachytre- chus, Campsicnemus, Scellus, Hydrophorus, Liancalus, Chrysoti- mus, and Xanthochlorus, whereas its coalescence with the South American fauna is apparent in the species of Paraclius, Pelasto- neurus, Lyroneurus, and Plagioneurus. The species of genuine Gymnopternus, so numerous in North America, are but scantily represented in Europe. The North American species of Diapho- rus agree in part with the European, in part with the South American species. The North American species of Argyra, Por- phyrops, Leucostola, and Liancalus do not show any striking difference from the European species of these genera, but just as little from the South American species. Of such species, as are common to Europe and North America, the following have hitherto come under my observation: Doli- chopus brevipennis Meig., Dolichopus plumipes Scop., Dolicho- pus discifer Stann., Scellus spinimanus Zett., and Psilopus pullens Wied. The first four of these species belong altogether to specific types commoffly represented on both continents; but this is not the case with Pszlopus pallens. This species unques- tionably belongs to the circle of European types of Psilopus, whereas all the North American Psilopus at present known closely approach the types of their South American brethren. It seems, therefore, not altogether unnatural to suppose that this SUPPLEMENT. gee species, which, according to Baron Osten Sacken’s statement, is not uncommon in the lower parts of New York City, should have been accidentally imported in ships from the south of Europe. As species common to both continents may perhaps be also re- garded Diaphorus nigricans Meig. and Xanthochlorus tenellus Wied.; the North American Diaphorus opacus might be con- sidered as identical with the first, Xanathochlorus helvinus with ‘the second of these species; certainty about this point, however, can only be acquired by the close comparison of a larger number of well-preserved specimens of the two American species. Il. Description of some Species communicated after the Volume had gone through the Press. Gen. Il. DOLICHOPUS. Corrected Table for determining the Species. if Prevailing color of the feet black. > ( Prevailing color of the feet yellow. 9 Cilia of the inferior orbit black. 3 Cilia of the inferior orbit whitish. 4 Face ochre-yellow. 1 gratus Zw. Face silvery white. 2 laticornis Lw. First joint of the hind tarsi with numerous bristles. 3 setifer Zw. First joint of the hind tarsi with a few bristles. ( Hind tibie black only at the tip. \ Hind tibie entirely black. ( The black color at the tip of the hind tibie is rather extended and Io nn | not very sharply limited. 4 albiciliatus Zw. 64 The black color at the tip of the hind tibiz but little extended and L sharply limited. 5 xanthocnemus nN. sp. A considerable extent of the tip of the femora yellow. 6 tetricus n. sp. The extreme tip of the femora only somewhat yellowish. 8 Lamelle of the hypopygium pointed. 7 acuminatus Zw. Lamelle of the hypopygium rounded ovate. 8 ovatus Lw. Cilia of the inferior orbit black. 10 Cilia of the inferior orbit pale. — - 12 10 { Fore coxe blackish. 9 pachycnemus Zw. Fore coxe yellow. 11 The first two joints of the antenne yellow. 43 dorycerus Lw. The whole antennez black. 10 brevipennis Me‘g. 12 { Tegule with pale cilia. ; 13 Tegule with black cilia. 26 o24 DIPTERA OF NORTH AMERICA. [PART II. 13 Antenne black, at the utmost the first joint almost yellowish-red. 14 Antenne, altogether or at least their larger portion, yellowish-red. 24 Fore coxe dark at the base, beyond the middle. 11 longimanus Lw. Fore coxe pale. 15 Tip of the hind tibiz distinctly black. 16 Tip of the hind tibiz not, or very slightly infuscated. 17 Fore tarsi only ferruginous-brownish. 12 brevimanus Lw. Fore tarsi blackened from the tip of the first joint. 13 socius Lw. Hind tarsi entirely black. 18 Basis of the hind tarsi to a considerable extent pale. 22 { Hind femora of the male not ciliated. 14 nudus Lw. Hind femora of the male ciliated. 19 | The enlarged last joint of the fore tarsi of the male on the outside with a white reflection. 45 paleestricus Lw. ie The enlarged last joint of the fore tarsi of the male on the outside [ without a white reflection. : 20 ; Hind femora of the male very densely ciliated. 16 splendidus Lw. Hind femora of the male sparsely ciliated. 21 Hind tibie not infuscated at the tip; the fourth joint of the fore tarsi of the male somewhat broader than the preceding. 44 splendidulus Lw. 41 Hind tibize somewhat infuscated at the tip; the 4th joint of the fore tarsi of the male not broader than the preceding. 15 subciliatus Lw. (oo the last joint of the fore tarsi of the male enlarged. 22 17 batillifer Zw. (The two last joints of the fore tarsi of the male enlarged. 23 Hind femora of the male ciliated. 18 eudactylus Lw. Hind femora of the male not ciliated. 19 tonsus Lw. 24 | Last joint of the fore tarsi of the male enlarged. . 20 tener Lw. Fore tarsi of the male plain. 95 95 { Wings hyaline with a grayish tinge. 21 variabilis Zw. Wings hyaline with a yellowish tinge. 22 luteipennis Zw. 26 { Fourth longitudinal vein broken. oF Fourth longitudinal vein not broken. ol 97 { Antenne black. 23 ramifer Lw. Antenne yellowish red. 28 ( Fourth longitudinal vein broken twice at right angles. | te 28 4 24 bifractus Zw. The lower angle of the fourth longitudinal vein sharp, the upper one [ rounded. 29 99 tae of the male plain. 25 vittatus Lw. Fore tarsi of the male enlarged at the tip. o0 SUPPLEMENT. B25 39 § Hind femora of the male ciliated. 26 cuprinus Wied. Hind femora of the male not ciliated. 27 longipennis Lw. portion, blackened. 32 Antenne red, at the utmost the third joint at the tip, or its larger a] Antenne black, at the utmost the first joint, in part, red. 39 39 | Humeral callosity of the same color as the dorsum of the thorax. 33 Humeral callosity yellowish. ‘ 38 Arista of the antenne of the male very much enlarged at the tip. ss| 28 hastatus Lw. Arista of the antennez of the male plain. 34 34 | Last joint of the fore tarsi of the male not enlarged. 30 Last joint of the fore tarsi of the male enlarged. 36 ( First joint of the middle tarsi of the male feathered. 3 29 plumipes Scop. 54: ‘First joint of the middle tarsi of the male not feathered. 30 fulvipes Lw. ( Last joint of the fore tarsi of the male with a lamelliform appendage. 31 sexarticulatus Lw. a Last joint of the fore tarsi of the male without lamelliform appendage. l 37 37 | Last joint of the fore tarsi of the male small. 32 ruficornis Lw. Last joint of the fore tarsi of the male large. 40 lobatus Lw. 38 ! Fore tarsi of the male plain. 33 scapularis Lw. Fore tarsi of the male enlarged at the tip. 34 funditor Lw. 39 { Antenne entirely black. 40 First joint of the antenne partly red. 43 40 | Hind femora not blackened at the tip. 41 Hind femora blackened at the tip. 42 Al | Hind tibiz not blackened at the tip. 35 chrysostomus Lw. Hind tibiz blackened at the tip. 46 melanocerus Lw. { Anterior femora without dark streaks on the under side. 49 37 comatus Lw. Anterior femora with dark streaks on the under side. if 06 preustus Lw. 43 | First joint of the hind tarsi yellow, with the exception of the tip. 44 First joint of the hind tarsi entirely black. 45 ( Lamelle of the hypopygium ochreous-yellow, not double. 38 scoparius Lw. 44, Lamellz of the hypopygium ochreous yellow, double, that is, having an inner pair of flabs besides the outer ones. p 47 quadrilamellatus Zw. side. 46 | L Tips of the hind tibie at the utmost somewhat blackened on the in- a Tips of the hind tibie distinctly black. A7 326 DIPTERA OF NORTH AMERICA. [PART Il. ( The first joint of the antenne red on the under side only. 39 discifer Lv. ms The first joint of the antenne red, with the exception of its upper i side. 40 lobatus Lw. ( Hind tibiz of the male with bristles of unusual length. ne | 41 setosus Lw. : Hind tibie of the male with bristles of ordinary lensth. lL 42 incisuralis Lw. 43. D. dorycerus Loew. %.—ZMneo-viridis, oculorum tegularumque ciliis nigris, primis duobus antennarum articulis, coxis anticis pedi- busque saturate flavis. *. Seta antennarum lamellifera, tarsorum anticorum articulis ultimis quatuor dilatatis, atris. CN te ia a Metallic green; cilia of the posterior orbit and of the tegule black; the first two joints of the antennae, the fore coxe and the feet saturate-yellow. *,. Arista expanded into a lamella at the end, the last four joints of the fore tarsi enlarged, deep black. - OLA GR A aun a Long. corp. 0.26. Long. al. 0.26. Syn. Dolichopus dorycerus Lozw, Berl. Ent. Zeitschr. VIII, 93, 85. Male. Bright, bronze-green, usually with extensive coppery- red reflections. Antenne small; the first and second joints, which are very much obliterated, of a saturate-yellow color; the third joint, which is round, and the arista, black ; the latter bears at its tip an elliptical black lamella. The face more ochre-brown than ochre-yellow; the cilia on the posterior orbit altogether black. Hypopygium black; the lamelle of middling size, dingy white with a rather broad black margin, jagged on the edge and beset with black bristles, on the upper margin with black hairs. Fore coxe with black hairs. Feet saturate-yellow; hind femora before the tip usually with two, sometimes with one bristle; the hind tibize have upon their hind side, before the middle, a small brown callus, and are blackened at the extreme tip on the inside. Fore tarsi about as long as the tibie ; the first joint slender, stalk- like, considerably longer than the following four joints together, dark yellow, blackened only at the extreme tip; the following SUPPLEMENT. 827 four joints velvet-black, strongly compressed from the sides; the three last ones are expanded on the upper side into long lobes, which are velvet-black on the third and fourth joints; on the fifi.L joint the lobe is black only at the base, otherwise whitish. Middle and hind tarsi, from the tip of the first joint, black. Wings grayish-hyaline with dark-brown veins, tinged with clay- ish-yellow in the costal, marginal, and submarginal cells, thte costa only slightly incrassated at the tip of the first longitudinal vein; the tip of the third longitudinal .vein strongly deflected backwards; the last segment of the fourth longitudinal vein not broken ; the posterior margin of the wing has a deep sinus before the unusually protruding anal angle ; the latter is again sinvated, So as to appear bilobed. flab. Glen-House, White Mountains, New Hampshire, July 2, 1863. (Osten-Sacken.) 44. D. splemdidulus Lorw. %.—Viridis, nitidus, coxis anticis pedibusque flavis, tibiis posticis totis concoloribus, antennis tarsisque posticis nigris, ciliis oculorum inferioribus tegularumque ciliis flavi- cantibus, alarum vena longitudinali quarté non fracta. 3,. Tarsis anticis elongatis, articulo quarto precedentibus latiore, quinto compresso atro, femoribus posticis minus confertim flavo-ciliatis. lan aX . . e e e . Green, shining, fore coxe and feet yellow; the hind tibie not blackened ‘at the tip; antenne and hind tarsi black; cilia of the inferior orbit and of the tegulz yellowish. %,. Fore tarsi elongated, fourth joint broader than the preceding; the fifth joint laterally compressed, black ; hind femora ciliated with rather sparse yellowish hairs. SUN Tea Pattee ee | fs Long. corp. 0.22. Long. al. 0.22-0.23. Syn. Dolichopus splendidulus Lorw, Berl. Ent. Zeitschr. VIII, 91, 82. Male. Metallic green, bright, shining. Face rather bright- yellow. Antenne altogether black; the third joint short-ovate. Yront shining green. Cilia of the inferior orbit pale-yellowish. Lamelle of the hypopygium broad, ovate, whitish; on the upper and the apical margins with a very narrow blackish border ; apical margin jagged and beset with black bristles. The four hind coxe are blackish, only at the extreme tip yellow. Fore coxe vellow, somewhat blackened only at the extreme basis, beset with short 32 DIPTERA OF NORTH AMERICA. [PART IL black little hairs almost upon the whole front side. Feet yellow. The hind femora before the tip with a bristle, upon the greater part of the under side sparsely ciliated with rather long yellowish hairs. Hind tibie of ordinary strength, not infuscated at the tip, with a long glabrous streak upon the hind side. Fore tarsi abundantly one and a half the length of the tibie; the first four jdints yellow, on the inside with a somewhat whitish reflection ; stalk-shaped from the first to the third joint ; the fourth joint late- rally compressed, somewhat broader than the preceding, especially towards the tip; the first joint nearly as long as the three follow- ing together; the fifth joint black, compressed, broad, especially towards the tip, beset on the upper side with closely appressed little hairs. Middle tarsi blackened from the tip of the first joint. Hind tarsi altogether black. Cilia of the tegule whitish. Wings hyaline, somewhat grayish, of rather uniform breadth; the costa at the tip of the first longitudinal vein with a weak and very short swelling; the fourth longitudinal vein not broken. Hab. White Mountains, New Hampshire, July, 1863. (Osten- Sacken. ) | Observation.—This species has an extraordinary resemblance with D. splendidus on one side, and with D. subciliatus on the other. It differs from D. splendidus, with which it agrees more with regard to the structure of the fore tarsi, by the less densely ciliated hind femora, and by the smaller extent of the incrassa- - tion of the costa. D. subciliatus has longer and more slender fore tarsi, the fourth joint of which is as slender as the preceding ; it has the hind tibie infuscated at the tip; the cilia of its hind femora are not only more scarce but also shorter, finally the swell- ing of the costa is more extended. Moreover, not only D. splendi- dus, but also D. subciliatus are considerably larger than D. splen- didulus. ‘This character will enable us to distinguish the female of D. splendidulus from that of D. splendidus, as well as from the female of D. subciliatus ; the two latter, however, cannot be confounded on account of the different color of the hind tibiz. 45. D. paleestricus Lorw. 4% and 9.—Aneo-viridis, pedibus flavis, coxis anticis tibiisque posticis totis concoloribus, antennis tarsisque posticis nigris, ciliis oculorum inferioribus tegularumque ciliis flavi- cantibus, vena alarum longitudinali quarta non fracta. *%,. Ultimo tarsorum anticorum articulo admodum dilatato, nigro, in latere SUPPLEMENT. sat externo albo-micante; femorum posticorum ciliis flavicantibus, non confertis. ©. Pedibus simplicibus. Metallic green; feet yellow; fore coxe and the whole hind tibiz of the same color; antenne and hind tarsi black; cilia of the inferior orbit and of the tegule yellowish; the fourth longitudinal vein not broken. *,. The last joint of the fore tarsi very much enlarged, black, en the out- side with a white reflection; the yellowish cilia of the hind femora sparse. Q. Feet plain. Long. corp. 0.24. Long. al. 0.23. Syn. Dolichopus palestricus Lorw, Berl. Entom. Zeitschr. VIII, 92, 84. Metallic green, bright. Face of the male narrow, more pale ochre-yellowish than golden-yellow; the face of the female broader and paler. Antenne entirely black; the third joint of the male ovate, that of the female shorter. Front green, bright. Cilia of the inferior orbit yellowish. Fore coxe yellow, on the front side with a short black pubescence. The four posterior coxe yellow only at the extreme tip. Hind femora with a bristle before the tip. Fore tarsi of the female and middle tarsi in both sexes blackened from the tip of the first joint. Hind tarsi black, ex- cepting only the extreme basis, which is yellowish-brown. Cilia of the tegule yellowish. Wings grayish hyaline; fourth longi- tudinal vein not broken. Male. Uamelle of the hypopygium whitish, of moderate size and oval form; on the upper and apical margin they have a nar- row black border, the latter is jagged and beset with black bristles. Hind femora sparsely ciliated with yellow hairs. Fore tarsi once and a half so long as the tibie; the first four joints yellow, with a white reflection on their sides, slender, stalk-like ; the first joint as long as the three following together, the second abundantly one and a half so long as the third ;- the third some- what broader than the preceding, especially toward its tip; the fourth considerably shorter and broader than the third ; the fifth joint laterally compressed, very much enlarged, black, with a silky reflection ; on the outside this reflection sometimes appears almost ‘silvery. Hind tibize somewhat thickened ; the two thirds of their hind side without any pubescence. The costa at the tip of the first longitudinal vein with a rather elongated swelling. Hab. New Hampshire. (Osten-Sacken.) 530 DIPTERA OF NORTH AMERICA. [PART II. Observation 1.—D. palestricus is very much like D. batillifer. It differs from it in both sexes by the somewhat larger antenne, and principally by the hind tarsi, which are black as far as the extreme basis; moreover the male has distinctly shorter fore tarsi and their first three joints are somewhat stouter; the cilia of the hind femora are more scarce; the hind tibie are less thickened, and the glabrous spot on their hind side is longer. The female may be distinguished from the somewhat uncertain female of D. splendidus, and from the as yet unknown female of D. splendidu- _tus by the pubescence on the sides of the abdomen, which is, to a greater extent, of a pale color; from the female of D. nudus it differs by the under side of the first joint of the antenne not being red. Observation 2.—The discovery of the present species makes it necessary to mention, in the diagnosis of D. batillifer, the pale color of the first joint of the hind tarsi, and the very dense fringe of cilia on the hind femora of the male. 46. D. melamocerus Lorw. 4% and 9.— Aineo-viridis, antennis nigris, inferioribus oculorum ciliis flavicantibus. ciliis tegularum nigris, coxis anticis pedibusque flavis, tarsis anterioribus inde ab articuli primi apice, tibiarum posticarum apice tarsisque posticis totis nigris. *,. Facie subaurea, tarsis simplicibus, femoribus posticis flavo-ciliatis. @. Facie albicante, femoribus posticis non ciliatis. Metallic green; antenne black; cilia of the inferior orbit yellowish ; cilia of the tegule black; fore coxe and feet yellow; the four anterior tarsi, from the tip of the first joint, the tip of the hind femora and the whole hind tarsi black. *,. Face almost golden-yellow ; hind femora with yellowish cilia. Q. Face whitish ; hind femora not ciliated. Long. corp. 0.20. Long. al. 0.20. Syn. Dolichopus melanocerus Loew, Berl. Ent. Zeitsch. VIII, 93, 86. Male. Metallic green, bright. Front bright green. Antenne entirely black, rather large; the third joint elongated-ovate, rather of equal breadth. Face rather narrow, golden-yellowish, but not shining. Cilia of the inferior orbit yellowish. Lamellz of the hypopygium of medium size, ovate, whitish, with a narrow black border, jagged on the apical margin and beset with black bristles. Fore coxe yellow, somewhat blackened at the extreme basis, and clothed on the front side with a black pubescence. Feet yellow ; hind femora before the tip with a bristle, ciliated on SUPPLEMENT. Sor the under side with scattered yellowish hairs. Hind tibix at the tip, to a considerable extent, black; on the hind side with a gla- brous streak, which reaches from the basis up to the tip. Fore and middle tarsi blackened from the tip of the first joint; hind tarsi altogether black. Cilia of the tegule black. Wings with a rather dark-gray tinge, and with black veins ; the costa has, at the tip of the first longitudinal vein, a very short knot-like swelling ; the fourth longitudinal vein is not broken. Female. The plastic characters, which distinguish the male are wanting here, otherwise it resembles the male very much. The antenne are considerably shorter and their last joint is much smaller. The face is very much broader, grayish-white, with but little admixture of yellowish. ‘Hab. Canada. (Couper.) Observation.—The male cannot be mistaken for any other species. The female differs from that of D. comatus by its more considerable size, darker wings, and the absence of a dark tip on the hind femora. It cannot be mistaken for the as yet unknown female of D. chrysostomus, on account of the extended black color of the tip of its hind tibiz. All the other species, with the females of which it could be confounded, have the antennz not entirely black. 47. D. quadrilamelliatus Lorw. % and 9.—Viridis, nitens, an- tennis nigris, margine infero articuli primi rufescente, facie alba, inferi- oribus oculorum ciliis albidis, ciliis tegularum nigris, coxis anticis pedibusque flavis, tarsis posterioribus inde ab articuli primi apice nigris, alarum vena longitudinali quarta non fracta. *,. Duobus ultimis tarsorum anticorum articulis depressis, atris ; lamellis hypopygii ochraceis, bilobis. Q. Tarsis anticis inde ab articuli primi apice nigris. Green, shining; antenne black ; the inferior margin of the first joint red- - dish; fece white; the cilia of the inferior orbit whitish ; cilia of the tegule black; fore coxe and feet yellow, the four posterior tarsi from the tip of the first joint black; the fourth longitudinal vein not broken. *,. The two last joints of the fore tarsi flattened, black; lamelle of the hypopygium ochre-yellow, bilobed. Q. Fore tarsi from the tip of the first joint black. Long. corp. 0.27. Long. al. 0.26. Syn. Dolichopus quadrilamellatus Loew, Berl. Ent. Zeitschr. VIII, 92, 83. Male. Metallic green, shining. Front shining green. . a. head 9, b. head %, c. head 9, d. antenna %, and e. antenna ® of the same.—/. antenna Q of &. lugubre.—g. wing Q of R&R. longicorne. ~ 20. Kiphamdriwim quapririzatom Lw. %. a. head, and 6. head 9 of X. caliginosum Meig.—c. antenna % of X. quadrifilatum.—d. antenna %, e. antenna 9, and /, wing 2 of X. caliginosum. 21. Porphyrops metampus lw. %. a. head %, 6. head 9, c. antenna 4, d. antenna 9, and e. wing *%, of the same. 1 The antennal arista of the 4 was made by the engraver a little too long, that of the 9 a little too short. 2 Owing to a mistake, which was discovered too late, the posterior trans- verse vein is wanting in fic. fin some of the impressions of this plate. 22. 23. 2A. 25. 26. 27. 28. 29. 30. 31. 24. 35. 36. EXPLANATION OF THE PLATES. 343 Smiliotus maritimz Hal. >. a. antenna 4%, of S. thinophilus Lw.—b. antenna %, c. head %, d. head 9, ande. wing % of S. maritime. Aphrosylus raptor Walk. 4. a. antenna 4, b. and c. head %, d. wing % of the same. Thinophilus ruaviratris Zett. >. a. antenna 4%, b. head 4, c. head 9, d. wing ? of the same. Peodes rorcivatus Lw. 4%. a. head, b. head 9, c. antenna 4, d. wing % of the same. Nematoproctus pistenvens Meig. %. a. head %, b. head 9, c. antenna $, d. wing % of the same. 6 Leucostola ciyeviata Lw. %. a. head %, 0. antenna %, and c. wing % of the same. ¥ PLATE VI. Eutarsus avuicus Meg. 4. a. head %, 0. antenna 4, andc. wing % of the same. Diaphorus srecrasius Lw. %. a. head 4%, 0. head 9 of D. sodalis Lw.—c. head %, and d. an- tenna %, of D. spectabilis.—e. wing Q of D. interruptus Lw. Lyromeurus c#rvutescens Lw. 9. a. head 9, b. the same from the side, c. antenna 9, d. wing 9 of the same. Chrysotus osuiquus Lw. 4. a. head 9, and b. head % of C. obliquus.—c. head % of C. vividus Lw.—d. antenna % of C. vividus.—e. antenna %, of C. obliquus Lw.—/f. antenna % of C. cornutus Lw.—g. wing 4 of C. vividus. Teuchophorus monacantuvs Lw. 4. a. head 4%, 0. antenna %, and c. wing % of the same. Campsicmemus ciavpicans Lu. %. a. head % of C. claudtcans.—b. middle foot % and antenna 4, of C. hirtipes Lw.—d. antenna % and wing 9 of C. claudicans. Sympycnus nopatus Lw. 4. a. head %, b. head 9, c. antenna 9, d. antenna % of S. nase — e. wing % of S. tertianus Lw. Liancalus cenvauis Iw. %. a. antenna %, b. head 9, c. head %, and d. wing 9 of the same. Plagioneurus onivirratus Lw. 9. a. head 2, b. antenna 9, and c. wing 9 of the same. oo woe i DIPTERA OF NORTH AMERICA. [PART it. PLANE y Uf. 3%. Scelius avints Lw. 4. a. head %, 6. antenna %, and c. wing % of the same. 38. Hydrophorus innoratus Lw. %. a. antenna 4, b. head 9, c. wing % of the same. 39. Medeterus piapema Linn. %. a. and b. head %}, c. antenna 4, and d. wing 9 of the same. 49. Achalcus Fruavicouus Meg. 9. a. and b. head 9, c. wing 9, andd. wing @ of the same. 4i. Xanthochiorus wHeivinus Lw. %. a. head %, b. antenna %, c. wing 4 of X. ornatus Hal. 42. Chrysotimus pvsio Lw. %. . = a. head 9, b. antenna %, ce. wing % of C. molliculus Fall. 43. Saucropus pimipiatus Lw. %. a. antenna 9 from the outside, 6. antenna % from the inside, ce. head 9, d. head 4, and e. wing % of the same. 44, Psilopus riuires lw. 4. a. head %, of Ps. filipes.—b. head % of Ps. scobinator Lw.—c. head *, of Ps. pallens Wied.—d. antenna %, of Ps. scintillans Lw.— e. antenna -%, of Ps. pilosus Lw.—/f. antenna %, of Ps. comatus Lw.—g. antenna % of an undescribed species from Ceylon, related to Ps. globulifer Wied.—h. wing % of Ps. psittacinus Lw.—i. wing % of Ps. scobinator. REMARKS ON THE GENERIC CHARACTERS, EXPLANATORY TO THE PLATES. AuttHoueH the present publication on North American Dolichopodide was based upon a considerable number of species, it can be safely assumed that these species do not represent all the Genera occurring in North America. I have, therefore, added the characters of even those genera of the family, representative species of which have not yet been found on that continent, and I hope that this addition will prove useful to those desirous of studying this family in detail. In order to facilitate the recog- nition of generic characters, five plates, drawn for this purpose, have been added to this volume. But as on these plates every genus is represented only by a single species, this might easily give rise to the mistake that specific marks belonging to that particular species are generic characters. In order to prevent this, ] have deemed it advisable to append to the plates the following explanatory remarks on the generic characters, which should always be consulted in determining species. The figures of the antenne show that the first joint in No. 1—16 is dis- tinctly provided with bristles on the upper side ; in No. 17—44, on the con- trary, it is glabrous. This distinguishes the two principal divisions of the Dolichopodide. Among the species belonging to the FIRST PRINCIPAL DIVI- SION the genera numbered from 1 to 12! have a completely disengaged, elongated hypopygium ; those numbered 14—16 a small, rounded, more or less imbedded one; in No. 15 the hypopygium is short and sessile, but not imbedded, so that this genus (Diostracus) forms a transition from one of these two subdivisions to the other, and may be included either in the first -orin the second. I have given preference to the first arrangement, but have separated this genus from all the others of this subdivision on account of the very large size of the palpi of the male. The other genera of the First Sub-division stand much nearer to each other in their organization ; they may, however, be easily arranged into two groups according to the circumstance whether the first joint of the hind tarsi is provided with bristles on its upper side (No. 1—3), or is without such bristles (4—16). To th® jirst of these groups belong : Hygroceleuthus (1), Dolichopus (2), and Rhagoneurus (3). The difference between 1 These numbers refer to the plates. ( 345 ) 2 346 DIPTERA OF NORTH AMERICA. [ PART 166 Hygroceleuthus and Dolichopus consists in the structure of the head, which is higher and narrower in Hygroceleuthus, especially in the males, and in the length of the face, which reaches farther down in Hygro- celeuthus and gives to the head a different profile. The genus Rhago- neurus differs from Tachytrechus and Dolichopus by the feathered arista of the antenne and the different structure of the male abdomen, which is a little compressed laterally, as also by the fracture of the last segment of the fourth longitudinal vein peculiar to it, and in which it is not equalled by any of those species of Dolichopus which have the last segment of the fourth longitudinal vein also fractured ; in the structure of the head Rha- goneurus agrees with Dolichopus, in that of the hypopygium with Doli- chopus and Tachytrechus.! ! Mr. Rondani has established the genus Rhageneura on those European species of Dolichopus, the fourth longitudinal vein of which is broken. This genus cannot be retained in this sense for several reasons. 1. Because. these species do not differ at all from the other species of the genus in the other parts of their organization. 2. Because the fracture of the fourth longitudinal vein of these species is very different in kind as well as in degree. 3. Because this fracture in some species is sometimes present, sometimes not. I have already stated above, on p. 19, that Dol. ziczac Wied. requires the establishment of a new genus. At that time I knew only this one species of the newly proposed genus, and considered therefore its establishment as premature. Since then I have become acquainted with several species, so that I feel prepared now to introduce this new genus, and take occasion at the same time to furnish a description of the typical species which I have figured. I propose for this new genus the name of Rhageneura, introduced by Rondani in a somewhat different sense, modifying it only in the more correct Rhagoneurus: The characters of this genus are: First joint of the antenne with bristles on the upper side ; the arista of the antenne feathered or hairy; first joint of the hind tarsi with a bristle; fourth longitudinal vein twice broken at right angles, with a considerable stump of a vein at each angle of the fracture; abdomen of the male a little compressed laterally ; hypopygium entirely ceehae as in Dolichopus. The figured species is the following :— Rhagoneurus polychromus nov. sp. % and 9 .—Viridis, thorace violaceo- et cupreo-variegato, fronte violaced, antennis rufis, pedibus flavis, alis cinereis, venis transversis non infuscatis. « * . Facie ochraced, hypopygii margine supero et apice fiavis, lamellis parvis, albicantibus, tenuissime nigro-marginatis. ©. Facie albida. Green with violet-and coppery spots on the thorax; front violet; an- tenne red; feet yellow; wings gray; the transverse veins without a dark margin. s. Face ochraceous; upper margin and tip of the hypopygium yellow, the small lamelle whitish, with a very narrow black margin. REMARKS ON THE GENERIC CHARACTERS. 347 The peculiar ornaments, which the figured males of Hygroceleuthus and Dolichopus possess, as well as the strong swelling of the costa before the tip of the first longitudinal vein in Hygroceleuthus are not generic, but merely specific characters which, moreover, do not belong to the females. To the second group belong the genera Gymnopternus (4), Paraclius (7), Pelastoneurus (5), Tachytrechus (6), Orthochile (8), Hercostomus (9), Sybistroma (10), Hypophyllus (11), and Haltericerus (12). The genus Gymnopternus, if understood in the limited sense adopted above, differs from all the other genera of this group by the parallelism of the third and @. Face whitish. Long. corp. 0.17. Long. al, 017. Shining metallic green. Front bright, violet-blue, antennz yellowish- red; the pubescence on the upper side of the first joint rather short ; the third joint rounded-ovate, however but little rounded at the end; shorter in ‘the female than in the male, in both sexes blackened to a very small extent on the upper margin and at the extreme tip. The arista of the antennz in both sexes with a considerable feathery pubescence. Face of the male not very narrow, ochre-brownish; the face of the female broad, whitish. Cilia of the inferior orbit yellowish. Upper side of the thorax with copper-colored spots and with violet-blue reflections; the former are more striking in the male than in the female, while the latter are visible either on the hind part of the dorsum of the thorax only, or spread on its middle more towards the front. Scutellum violet-blue with blue-green margins. Abdomen metallic green, often coppery upon most of the upper part, black at the incisures, covered on the sides with a rather strikingly white dust; the hypopygium rather small, its second segment yellow along the margin, which is turned towards the venter, and at the tip; its external lamelle scarcely of middling size, yellowish-white, with a very narrow black margin, on the edge of the margin a little jagged and beset with crooked black bristles. Coxe yellow; the foremost are beset, besides the usual black bristles, with short and fine black hairs ; the outside of the middle cox is almost entirely covered by a large gray-black spot. Feet yellowish, even plain in the male; hind femora with a bristle before the tip; fore tarsi brownish-yellow, about as long as the tibie; middle and hind tarsi infuscated from about the tip of the first joint, brownish-black towards the end; the hind tibie of the male without glabrous spot on the hind side; the first joint of the hind tarsi in both sexes has only one or two strong bristles on the upper side. Tegule with black cilia. Wings tinged with dark gray with brownish-black veins ; the last segment of the fourth longitudinal vein is interrupted twice at right angles, and has, at each interruption, a long stump of a vein, as the other species of this genus ; transverse veins without-any trace of dark margin; in the male the costa has a slight swelling immediately before the end of the first longitudinal vein. Hab. Ceylon. 348 DIPTERA OF NORTH AMERICA. [PART II. fourth longitudinal veins of the wings; it stands in rather close relation to the genus Dolichopus, which belongs to the first group, differs from it, however, not only by the want of bristles on the first joint of the hind tarsi, but also by the smaller size of its species, the shortness of the first joint of the antennez, and usually by the more distinct pubescence of the arista; moreover the lamelle of the hypopygium are usually smaller and not jagged at the end. The genus Paraclius is distinguished by a pecti- nate or subpectinate arista of the antennez, by the face, narrowed below even in the female, and by the peculiar course of the fourth longitudinal vein, the end of which forms a curve with its concavity turned backwards. Closely related to Paraclius is Pelastoneurus; the distinction between both genera is easy, if attention is paid to the essentially different course of the fourth longitudinal vein, to the very much more broad: face, which is also more convex upon its lower part, and to the not sessile but pedun- culated hypopygium of the species of Pelastoneurus, which have the feathered arista of the antennze in common with the species of Paraclius. The genus Tachytrechus is very easily recognized by the great length of the perpendicular diameter of the very hairy eyes, by the face, whieh is narrower towards the middle but broader towards the bottom, and reaches entirely as far as the inferior margin of the eyes; the palpi are also com- paratively small in the female, and the fourth longitudinal vein has before the middle of its last segment a gentle flexure, from which it converges towards the third longitudinal vein; the figures of the antenne of the male of T. moechus, which remind of the structure of the antenne of Haltericerus, are an exception to the rule; however a similar structure occurs by way of exception in the genus Dolichopus. The genus Ortho- chile is so much distinguished by the structure of the proboscis and of the palpi as also by the distance of the tips of the third and fourth longitudinal veins from the tip of the wing, that it cannot be mistaken for any other genus. The genus Hercostomus, to which is to be added a large portion of those species which in my previous works I have com- prised in the genus Gymnopternus, embraces a variety of organizations and is evidently capable of a subdivision into several genera; in its whole structure it shows the greatest resemblance to Gymnopternus, but in all the species the third and fourth longitudinal veins, towards their ends, are rather strongly converging, while in the species of Gymnopternus they are either entirely parallel, or show but a very slight trace of convergency ; the hypopygium has, in its structure, a great similarity with that of Doli- chopus, but in some species the internal appendages are elongated, brush- like and hairy, like those of Hypophyllus and Haltericerus, which, how- ever, is also the case with some few species of Gymnopternus. The genus Sybistroma, which hitherto remained confined only to a few species, is nearest to the genus Hercostomus, differs, however, by the scutellum which is much clothed with hair, by the peculiar structure of the face of the female which is much protruding below, and by the peculiar structure of the arista of the male, The species of Hypophyllus are easily distinguished REMARKS ON THE GENERIC CHARACTERS. 349 by the slender structure of the whole body, by the length of their slender feet, by their pedunculated, usually yellow hypopygium, which is pro- vided with narrow, linear external appendages and elongated, more or less penicillated, internal appendages, likewise by the always very pro- minent development of the first joint of the arista of the antennz, which is different, however, in different species; the scutellum is glabrous and the lower part of the female face not protruding. The species of Haltericerus are more robust than the species of Hypophyllus; the face of the male is very narrow, that of the female very broad; the second joint of the antenne in both sexes, especially in the males, is rudi- mentary, and the arista very elongated in the latter and enlarged at its tip into a lamella; the hypopygium, attached toa long peduncle, and its appendages, bear the greatest resemblance to those of the species of Hypophyllus. To the above-named genera of the first group is appended Diostracus (13), as an anomalous genus. The very broad face in both sexes, the palpi, much larger in the male than in the female, the very small third joint of the antenne, the incrassated fore femora, the rounded, but not imbedded hypopygium, with its very small appendages and the long nar- row wings, with the posterior transverse vein very close to the margin— all these characters render this genus very easy to recognize. To the Second Sub-division, which is distinguished by the small, more or less imbedded hypopygium, belong the following genera: Anepsius (14), Argyra (15), and Syntormon (16). In Anepsius the second joint of the antenne has the usual transverse form, and the arista is inserted very close to its basis; the third joint of the antenne shows a distinct pubes- cence; the first longitudinal vein is short, the fourth parallel with the third; the abdomen of the male is laterally compressed. The relation- ship between Anepsius and the genus Sympycnus, which belongs to the second principal division, cannot be mistaken, though the distinct pubes- cence of the first joint of the antenne distinguishes it very easily from the other. The genus Argyra is distinguished by the transverse form of the second and the rather considerable size of the third joint of the antenne, its subapical arista, the broad wings—particularly towards the basis, the length of the first longitudinal vein, its distance from the costa and the inflection of the fourth longitudinal vein; to these characters may be added, in most of the species, the delicate, but striking silvery white tomentum, spread over a large part of the body. Argyra is closely related to Leucostola, the first joint of the antenne of which, however, is glabrous on the upper side. The genus Syntormon differs from all the other genera of the whole first principal division by the form of the second joint of the antenne, which, on its inner side, overlaps the third joint in the shape of a thumb; the face of the male is narrow, that of the female broad and protruding below like a roof; the arista of the antennz is com- pletely or almost completely apical; the third longitudinal vein is parallel or almost so. S50). DIPTERA OF NORTH AMERICA. [PART Il. The SECOND PRINCIPAL DIVISION of the Dolichopodide is divided, according to the shape of the third joint of the antenne, into two sub-divisions; the genera of the jirst sub-division (No. 17-23) have this joint, either in both sexes or at least in the male, pointed and provided with an apical arista; in the genera of the second sub-division (No. 24-44), it is short in both sexes, and if it should be somewhat elongated in the male, it is not pointed, and the arista is either dorsal, or, at the utmost, sub- apical. The genera of the First Sub-division are divided into two groups. To the first group belong those genera, the posterior transverse vein of which is distant from the margin of the wing. They are the following: Synarthrus (17), Systenus (18), Rhaphium (19), Xiphandrium (20), Porphyrops (21), and Smiliotus (23). Synarthrus shares with Syntormon not only the peculiar structure of the second joint of the antenne, but also the remain- ing characters, with the single exception of the first joint of the antenne, which is glabrous. Systenus strikingly differs from all the other genera of the group by the pointed abdomen and the very pedunculated hypo- pygium of the male; to its distinguishing characters may also be reckoned — the distinct pubescence of the third joint of the antenne, and the remark- ably sharp dividing line between the lower part of the face and the upper one. Rhaphium stands in close relation to the two following genera, is however distinguished from them by the very elongated antennz, even in females, and by the still more considerable stoutness of the female pro- boscis ; moreover from Xiphandrium it is distinguished by a less slender structure of the body, a much stronger pubescence, and a stronger flexure of the fourth longitudinal vein. The species of Xiphandrium have, like the species of Porphyrops, only in the males an elongated third joint of the antenne, in the females it is short; their difference consists in a greater slenderness, less pubescence, and less flexure of the fourth longitudinal vein; moreover the largest species of Xiphandrium are scarcely equal in the length of their body to the smallest species of Porphyrops. The dis- tinguishing characters of the genus Porphyrops become manifest from what has just been stated about the two preceding genera. The genus Smiliotus has the antenne of equal size and form in both sexes; they have on the under side, from the tip almost to the base, a distinct ex- cision; the face of the male is broad, and its palpi are as large as those of the female; finally, the abdomen shows externally one segment less than the related genera; the feet are comparatively short and rather vigor- ous; the small hypopygium is deeply imbedded and its appendages are “iron difficult to perceive. To the second group, which is characterized by a close proximity of the transverse vein to the posterior margin of the wing, belongs the only genus Aphrosylus (23); the third joint of its antenne is but little elongated, but pointed ; the pendant palpi are larger in the male than in the female ; the proboscis is bent towards the chest, the face is narrower above, and REMARKS ON THE GENERIC CHARACTERS. Som the eyes are excised near the antenne; the feet have rough bristles, and the first joint of all the tarsi is much longer than the second. Among all genera of the Second Sub-division Psilopus is distin- guished by the slender structure of its body, and especially of its feet, its very broad and more or less excavated front, the smallness of its antenne, and finally by its fourth longitudinal vein, which is provided with a pos- terior branch. I have assigned to it a position altogether at the end of the second sub-division, and will revert to it there. The other genera of this sub-division may be distributed into two groups according to the struc- ture of the thorax. To the first group belong those genera, the upper side of the thorax of which is convex, as far as the scutellum (No. 24-39) ; to the second those, where the upper side of the thorax, before the scutellum, bears an inclined, more or less concave, area (No. 40-43). The genera belonging to the first group, and possessing a sixth longi- tudinal vein, form the jirst sub-group; those where this vein is wanting, form the second sub-group. The jirst sub-group contains either such genera as have the transverse vein not close to the posterior margin of the wing, or such where an approximation of that kind takes place inastriking manner. The genera, where there is no striking approximation of the posterior transverse vein to the margin of the wing, are: Thinophilus (24), Peodes (25), Nemato- proctus (26), Leucostola (27), Eutarsus (28), Diaphorus (29), Lyroneurus (30), Chrysotus (31), Teuchophorus (32), Sympyenus (34), Campsicnemus (33), and Plagioneurus (36). Thinophilus has the small and but little imbedded hypopygium in common with Peodes (in all the other genera that belong here, it is much more imbedded) ; it differs from Peodes by the structure of the face, which, in both sexes, is broader below, and has an angular margin; by the large palpi of both sexes, and the very small size of the interior appendages of the hypopygium ; the first.two joints of the antenne are small, the third somewhat in the shape of a lens, and the arista dorsal; the last segment of the fourth longitudinal vein, towards its end, is parallel, or almost so, to the third longitudinal vein; the feet of the male are usually variously adorned. The structure of the body of Peodes resembles in general that of Thinophilus; the structure of the antenne and of the wings is also nearly the same, only the parallelism of the third and fourth longitudinal veins is still more complete than in most of the species of Thinophilus ; both of the interior appendages of the hypopygium form a large horny forceps; the tarsi of the male of the only species hitherto known are plain. The species of Nematoproctus, in the whole structure of the body, are nearest the species of Porphyrops ; they can be, however, easily distinguished from them by the rounded, and in both sexes small, third joint of the antenne, and by the arista, which is inserted in the neighborhood of the basis. They are less closely related to the genus Leucostola, because the elongation of the first longitudinal vein, the broad shape of the wings, and the subapical position of the arista are wanting in them; the same characters and the glabrousness of the 352 DIPTERA OF NORTH AMERICA. [PART II. first joint of their antenne distinguish them from the species of Argyra. The genus Leucostola stands to Argyra in the same relation as Synar- thrus does to Syntormon, that is to say, it differs from it only by the first joint of the antenne being without hairs; the considerable size of the third joint of the antenne, the subapical position of the arista, the great breadth of the antenne towards the basis, the considerable length of the first longitudinal vein and its great distance from the costa, are characters shared by Argyra; most of the species of Leucostola have also, like the species of Argyra, a delicate, almost silvery white tomentum, which covers a considerable portion of the body. Hutarsus is very near to Diaphorus ; the difference is, that the former has the third joint of the antenne some- what larger and that the transverse vein is a little more removed from the ' posterior margin of the wing; moreover the face of the males of Eutarsus is narrower, the bristles of the imbedded hypopygium are less striking, the first joint of the hind tarsi is shorter, and the pulvilli of the fore tarsi are, although also enlarged, not so elongated as in Diaphorus. The genus Diaphorus is represented in North America by particularly varied forms ; its distinction from Eutarsus has been explained above; from Lyroneurus it differs by the altogether different neuration of the wings, from Chrysotus by the greater slenderness of the whole body, and especially of the feet, and the comparatively longer and generally also proportionally narrower wings ; moreover the structure of the head is different, as, while the eyes of the males of Diaphorus are either contiguous avove the antenne or at least are separated by an equally broad front, those of the males of Chrysotus are sometimes contiguous below, but never above the antennez, and the front is always considerably widened above ; this difference in the structure of the front exists also in the females of both genera; finally, the males of Diaphorus distinguish themselves by the remarkable prolongation of the fore tarsi or of the fore and hind tarsi, and by the particularly striking manner in which the small imbedded hypopygium is provided with bristles, which characters are not found in the species of Chrysotus; the neuration varies in the different species of Diaphorus in consequence of several modifications in the position of the posterior transverse vein; in . no species, however, is this vein approximated to the posterior margin of the wing; the end of the last segment of the fourth longitudinal vein is sometimes cut off from the preceding part of it and pushed nearer to the anterior margin of the wing, so that both parts are either completely sepa- rated from each other or at least connected by an indistinct rudiment of a vein, as the illustration of the wing of Diaph. interruptus shows it. The genus Lyroneurus has a superficial resemblance to Diaphorus in the structure of the body, differs, however, strikingly by the large wings, with a more or less apparent greasy lustre, by the costa, which Is usually thickened in both sexes, or at least in the male, toa very great extent ; ; by the end of the third longitudinal vein being strongly turned pau ratte: and by the wide space between the fourth and the third longitudinal veins ; the hypopygium is usually less provided with bristles than in the species REMARKS ON THE GENERIC CHARACTERS. ooo of Diaphorus ; the males of Lyroneurus, known to me, show no elongation of the pulvilli of the fore tarsi: The genus Chrysotus contains only small, mostly bright-green species, which cannot be mistaken for any other of the following genera, and which are sufficiently distinguished from Dia- phorus by the already mentioned characters; the statements made above in regard to the shape of the front, the absence of bristles upon the hypo- pygium, and the absence of the elongation of the pulvilli on the fore tarsi of the male, will help to recognize whether a given species, unless its female alone is known, is to be reckoned to Chrysotus or to Diaphorus ; as to the female, the structure of the front, the form of the wings, and the greater or smaller slenderness of the feet, have to guide us in its location. Striking is the very different form of the third joint of the antenne of the different species of Chrysotus in North America. The species of Teucho- phorus resemble more or less the smallest species of Chrysotus, are how- ever very easily distinguished in the male sex by the somewhat laterally compressed abdomen, by the feet which are beset with single, scattered, strong bristles, and by the crooked and variously adorned hind tibie; moreover, in all the known males of Teuchophorus there is a large black swelling on the costa before the tip of the first longitudinal vein, which is altogether an exception in the genus Chrysotus. More attention is neces- sary in order to recognize the females of Teuchophorus ; the best guide in this case is the steep position of the posterior transverse vein, the anterior end of which is nearer to the basis of the wing than the posterior end, and the comparatively small antenne, the arista of which is somewhat less approximated to the apex than in.most of the species of Chrysotus. The genus Sympycnus contains only small, mostly but little shining species, which are characterized by the smallness and the distinct pubescence of the third joint of the antennez, the insertion of the arista in the vicinity of its basis, the laterally compressed abdomen of the males, the not elongated metathorax, and the wings being more or less narrowed towards the basis; they have the greatest analogy to the species of Anepsius, the first joint of the antenne of which, however, is clothed with hair; fram Campsicnemus they are distinguished by the not elongated metathorax, by the abdomen, which is longer and not flattened from above, and by the face, which is narrowed towards the bottom; the end of the fourth longi- tudinal vein converges somewhat, in the European species, towards the third longitudinal vein; in the North American species it is parallel with it or almost so. (The want of the small transverse vein, and of the sixth longitudinal vein, which occurs in a number of the impressions of Tab. VI, are merely mistakes of the engraver, which were discovered too late for correction.) Campsicnemus is distinguished by its face attenuated upwards, the distinctly elongated metathorax, and the short and, in both sexes, much flattened abdomen; the third joint of the antennz is small, or rather small, and in most of the species somewhat pointed ; the dorsal arista is inserted in rather close proximity to the basis; the fourth longi- tudinal vein is always parallel to the third, and runs before its middle over 23 304 DIPTERA OF NORTH AMERICA. [PART II. a distinct convexity of the wing. The males are usually distinguished by striking ornaments on their feet, especially on the middle feet. The species of Plagioneurus are altogether distinct on account of the very diagonal position of the posterior transverse vein; otherwise their neuration is very near to that of Pelastoneurus, while the glabrousness of the first joint of the antennz renders it utterly impossible to mistake them for any species of the latter genus. ~To the second sub-group, embracing those genera the transverse vein of — which is strikingly approximated to the posterior margin of the wing, belong the following genera: Liancalus (35), Scellus (37), and Hydro- phorus (38). Liancalus is easily distinguished from Scellus and Hydro- phorus by ali the femora being slender and unarmed. In the species of Scellus the fore-femora are beset on the under side with rather strong bristles, catching into a row of similar bristles of the fore tibiw#, and the third and fourth longitudinal veins are rather strongly convergent toward their ends, while the species of Hydrophorus have only on the under side of the fore-femora, towards the basis, a few elongated thorn-like bristles ; the under side, however, not only of the fore-femora, but also of the fore tibiz, is beset only with short bristles, and the third and fourth longitudinal veins are parallel towards their ends, or almost so. To the next following genus, Achalcus, I have assigned this position on account of the general structure of its body, which led me to suppose the existence of a relationship between it and the following genera; I also presume, therefore, that the structure of the dorsum of the thorax, which I have not been able to ascertain positively in any of the few specimens belonging to me, will, when found out, justify the location I have assigned to the genus. In general the species of Achalcus may be easily dis- tinguished, as the total absence of the sixth longitudinal vein is a cha- racter peculiar to them; the species hitherto made known are of a non- metallic color, and of a very small size. The genera belonging to the second group, the thorax of which has on its posterior part a more or less concave, sloping surface, are the following : Medeterus (39), Chrysotimus (41), Xanthochlorus (42), and Saucropus (43). Medeterus differs essentially from the other three genera by the apical position of the arista, the very large size of the proboscis, and the totally disengaged hypopygium. The genera Chrysotimus and Xantho- chlorus contain only small species, and are easily distinguished by their coloring, which is either entirely yellow, or in part yellow, in part metallic- green; Chrysotimus is easily distinguished from Xanthochlorus, by the subapical position of the arista and by the much smaller and imbedded hypopygium ; with Xanthochlorus the position of the arista of the antennze is dorsal, and the swollen and rather disengaged hypopygium is directed backward so as to assume the appearance of a prolongation of the abdomen of the male. The species of Saucropus are of a more considerable size than the species of Chrysotimus and Xanthochlorus, and their feet are comparatively longer; the second joint of the antenne somewhat differs REMARKS ON THE GENERIC CHARACTERS. 355 from the usual transverse form, as, on the inside, it reaches a little over the third joint; the arista is dorsal; the sixth longitudinal vein runs as far as the margin of the wing ; the course of the last segment of the fourth longitudinal vein varies in the different species, nevertheless it always shows a distinct convergency towards the third longitudinal vein; the first joint of the hind tarsi is always considerably shorter than the second. The color of all the species is either entirely yellow, or reddish-yellow, or partly so. The genus Psilopus (44), closing the series, has the last segment of the fourth longitudinal vein provided with a posterior branch; this cha- racter is not wanting in any of the American, European, or African species that are known to me; in some South Asiatic species, however, it is repre- sented only by a fold of the wing, which sometimes is very indistinct. Besides, the species of Psilopus are very easily recognized by the slender- ness of the whole body and especially of the feet, by the very broad, more or less excavated front, by the small antenne, provided with a long, thin, dorsal or subapical, rarely almost entirely apical arista, and by the entirely disengaged hypopygium. In the living state they keep the wings divari- cated, which gives them an entirely different aspect from all other genera. The males have their feet variously adorned, and in some species they are distinguished by a structure of the wings peculiar to them. PND EX. Achalcus, 217 Agonosoma, 230 Anepsius, 123 Aphrosylus, 148 Argyra, 123 Argyra albicans Lw., 125 albiventris Lw., 128 calceata Lw., 131 calcitrans Lw., 130 cylindrica Lw., 132 diaphana Fbr., 126 minuta Lw., 129 nigripes Lw., 127 ' Campsicnemus, 193 Campsicnemus claudicans Lw., 194 hirtipes Zw., 193 Chrysotimus, 220 Chrysotimus delicatus Lw., 222 pusio Lw., 221 Chrysotus, 171 Chrysotus abdominalis Say, 172, 291 affinis Lw., 178 auratus Lw., 183 concinnarius Say, 172, 291 cornutus Lw., 174 - costalis Lw., 179 discolor Lw., 182 incerus W/k., 172, 308 longimanus Lw., 175 nubilus Say, 172, 291 obliquus Lw., 176 pallipes Zw., 183 picticornis Lw., 184 subcostatus Lw., 181 validus Lw., 175 viridifemora Macq., 172, 298 vividus Lw., 178 Condylostylus, 230 Dasypsilopsus, 230 Diaphorus, 156 Diaphorus interruptus Zw., 168 lamellatus Lw., 165 leucostomus Lw., 166 mundus Lw., 161 opacus Lw., 160 sodalis Lw., 163 spectabilis Lw., 162 Diostracus, 120 Diostracus prasinus Zw., 121 Dolichopus, 18, 323 Dolichopus abdominalis Say, 20, 292 acuminatus Lw., 34 adjacens W/k., 22, 312 adjustus Wied., 16 affinis W/k., 21, 310 albiciliatus Zw., 31 batillifer Lw., 45 bifractus Lw., 53 bifrons W/k., 20, 301 brevimanus Lw., 39 brevipennis Meig., 37 chrysostomus Lw., 67 ciliatus W/k., 31, 312 coércens W/k., 22, 312 comatus Dw., 69 confinis W/k., 23, 315 confusus Ztt., 71: consors WI/k., 21, 302 conterminus W/k., 23,315 contingens W/k., 21, 302 contiguus WI/k., 23, 314 cupreus Say, 56 cuprinus Wied., 55, 311 discessus W/k., 23, 314 discifer Stann., 71 distractus WI/k., 23, 313 dorycerus Lw., 326 eudactylus Lw., 46 ( 357 ) 358 INDEX. Dolichopus varius W/k., 21, 304 vittatus Lw., 55 xanthocnemus Lw., 31 ziczac Wied., 16 Dolichopus exclusus W/k., 23, 314 femoratus Say, 290 finitus W/k., 22, 313 fulvipes Lw., 61 funditor Lw., 66 gratus Lw., 29 grenlandicus Ztt., 20 hastatus Lw., 59 Eurostomerus, 230 Eutarsus, 153 Eutarsus eques Lw., 154 hebes WI/k., 21, 302 heteroneurus Macgq., 20,| Gymnopternus, 75, 332 Gymnopternus albiceps Lw., 85 299 incisuralis Lw., 74 ineptus W/k., 21, 303 irrasus W/k., 24, 318 lamellipes W/k., 21, 311 Laticornis Lw., 29 lobatus Lw., 72 longimanus Lw., 38 longipennis Lw., 57 luteipennis Lw., 51 maculipes W/k., 21, 303 melanocerus Lw., 330 nudus Lw., 41 obseurus Say, 20, 290, 296 ovatus Lw., 35 pachycnemus, Lw., 35 palestricus Lw., 328 patellatus Meig., 71 pennitarsis Fall., 60 plumipes Scop., 60 plumitarsis Fall., 37 barbatulus, Lw., 82 chalcochrus Lw., 335 coxalis Lw., 335 crassicauda Lw., 95 debilis Lw., 95 despicatus Lw., 90 difficilis, Zw., 91 exiguus Lw., 337 exilis Zw., 84 fimbriatus Lw., 89 flavus Lw., 80 frequens Lw., 88 humilis Lw., 336 levigatus Lw.; 87 leucospilus Lw., 99 lunifer Zw., 89 meniscus Lw., 336 minutus Lw., 96 nigribarbus Lw., 91 opacus Lw., 93 parvicornis Lw., 92 preustus Lw., 68 pulcher W/k., 21, 304 pusillus Lw., 334 quadrilamellatus, Lw., scotias Lw., 81 331 spectabilis Zw., 85 ramifer Lw., 52 subdilatatus Lw., 86 remotus W/k., 24, 317 subulatus Lw., 80 ruficornis Dw., 63 tristis Lw., 83 scapularis Lw., 64 ventralis Lw., 97 scoparius Lw., 70 separatus W/k., 24, 316 | Haltericerus, 119 sequax W/k., 24, 317 Hercostomus, 116 setifer Lw., 30 Hercostomus unicolor Lw., 117 setosus Lw., 73 Heteropsilopus, 230 ~ © sexarticulatus Lw.,62 | Hydrophorus, 211 soccatus W/k., 24,317 | Hydrophorus albofiorens W/k., 216 socius Lw., 40 chrysologus W/k., 215 splendidus Zw., 44 glaber W/k., 215 splendidulus Lw., 327 innotatus Lw., 212 subciliatus Lw., 42 notatus Zeit., 305 tanypus Lw., 71 parvus Lw., 216 ° tener Lw., 49 pirata Dw., 214 terminatus W/k., 24, 316 spinimanus Zett., 305 tetricus Lw., 33 viridiflos W/k., 215 tonsus Lw., 47 Hygroceleuthus, 17 unifasciatus Say, 289 Hygroceleuthus latipes Lw., 17 variabilis Lw., 50 Hypophyllus, 118 politus Lw., 94, 334 INDEX. 359 Leucostola, 151 Psilopus calcaratus Zw., 272 Leucostola cingulata Zw., 152 caudatulus Lw., 271 Liancalus, 198 caudatus Wied., 239, 294 Liancalus genualis Lw., 199 Chrysoprasi(us) W/k., 242, Lyroneurus, 169 265, 305 Lyroneurus cerulescens Lw., 170 ciliatus Lw., 260 comatus Lw., 262 Macherium, 148 delicatus W/k., 241, 304 Margaritostylus, 230 diffusus Wied., 234, 235 Medeterus, 218 dimidiatus Lw., 246 Medeterus alboflorens W/k., 216, 310 femoratus Say, 233, 290, 295 chrysologus W/k., 215,309 filipes Lw., 286 exustus W/k., 203, 300 gemmifer W/k., 241, 305° glaber Wik., 215 309 guttula, Wied., 237 lateralis Say, 291 herveticus W ie, 243, 320 nigripes Lw., 219 incisuralis Macq., 241 punctipennis Say, 292 inermis Lw., 272 veles Lw., 219 inficitus W/k., 242, 307 viridiflos Wik. .» 215, 301 jucundus Lw., 258 Megistostylus, 230 lepidus W/k., 243, 300 Mesoblepharus, 230 longicornis, Fbr., 231, 294 Musca, 289 macula Wied., 234, 292 Musca longicornis Fbr., 289 melampus Lw., 253 mundus Wied., 240, 296 Nematoproctus, 150 ' nigrofemoratus WI/k., 242, 307 Oaristylus, 230 pallens Wied., 234, 275 Oedipsilopus, 230 patibulatus Say, 233, 251 Orthochile, 114 peractus W/k., 243, 319 Orthochile derempta W/k., 115, 318 permodicus W/k., 243, 320 pilosus Lw., 256 Paraclius, 97 portoricensis Macq., 241 Paraclius albonotatus Zw., 102 psittacinus Lw., 281 arcuatus w., 101 radians Macq., 240, 297,298 Pelastoneurus, 103, 337 Sayi Wied., 232, 293 Pelastoneurus abbreviatus Jw., 338 scaber Lw., 250 alternans Lw., 339 scintillans Ziw., 273 cognatus Lw., 109 scobinator Lw., 268 letus Lw., 106 sipho Say, 232, 247 lamellatus Lw., 338 sipho Macq., 241, 297 longicauda Lio: 104 solidus W/k., 243, 319 lugubris Lw. , 105 suavium W/k., 242, 306 vagans Lw., 107 tener Lw., 284 Peodes, 149 ungulivena WI/k., 243, 319 Plagioneurus, 196 unifasciatus Say, 232, 289 Plagioneurus univittatus Lw., 196 variegatus Lw., 278 Porphyrops, 142, 340 virgo Wied., 240, 295 Porphyrops fumipennis Lw., 146 longipes Lw., 340 Rhagoneura, 19, 346 melampus Lw., 144 Rhagoneurus polychromus Iw. , 346 nigricoxa Lw., 145 Rhaphium, 140 pilosicornis W/k., 808 Rhaphium lugubre, 141 rotundiceps Lw., 146 Psilopus, 229 Saucropus, 224 Psilopus albicoxa WI/k., 243, 307 —_| Saucropus dimidiatus Lw., 225 albonotatus Lw., 275 rubellus Lw., 226 amatus WI/k., 242, 306 superbiens Lw., 227 bicolor Lw., 280 tenuis Lw., 228 360 Scellus, 200 Scellus avidus Lw., 207 exustus W/k., 202 filiferus Lw., 209 spinimanus Ztt., 204 Sciapus, 230 Smiliotus, 147 Sybistroma, 115 Sympycnus, 185 Sympycuus frontalis Lw., 188 lineatus Lw., 189 nodotus /.2., 191 tertianus Lw., 187 Synarthrus, 134 Synarthrus barbatus Lw., 138 cinereiventris Lw., 137 INDEX. Synarthrus palmaris Zw., 135 Syntormon, 133 Systenus, 139 Tachytrechus, 109 Tachytrechus angustipennis Zw.,113 moechus Lw., 110 vorax Lw., 112 Teuchophorus, 185 Thinophilus, 148 Xanthochlorus, 223 Xanthochlorus helvinus Zw., 224 Xiphandrium, 141 AN ee a Nagenschiber so. 6 i : rh tng ; oy VWeager shitber se. H. Locm def. Dy | a A a | ir tng Ls a ee he ae oo ee ro fin" a ee aTatetéezettiate tt 52 37 y2: BSAC AGSS Pt BG. tot eteia eo s4