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BC 4 4, = 47% »: : , ? a A P x" - 4 - _— 4 eK be Wwe Gs oat : it ff Rye? : ra ited 7 im oD ky eu) i ae : ae =: ; 4 = te im iy Ny ae ’ 3 ] vy Pad > «] Ps v3 pa my 3 Ly Xe = iy Se ¥2: c i Ven ~~ = te ow h 4 = =f - po, soe ~ <6 « a § 7 i te, aii V\¢ : SY: ONY 4 ee a eS ee BULLETIN OF THE ILLINOIS STATE LABORATORY OF NATURAL HISTORY URBANA, ILLINOIS, U. S.A: VOLUME XII 1915, 1916, 1917 CONTRIBUTIONS TO THE NATURAL HISTORY SURVEY OF ILLINOIS MADE UNDER THE DIRECTION OF STEPHEN A. FORBES 1918 Include one set of : _ ‘covers and ads. + Goat Lib. Buck 2 Cloth + Duck i Pig 5 Light Brown ARTICLE I.| Dark Brown TURE Ty Fi THEODG Sask Introductio Dark Blue Physiograp Dark Gresk, / SB Succession z fret Plants of | Red’ 19/5 —/ 7 eon 3 Watcon Measuremé¢ Interpre| Tan Summar : Measurem Olive interpre Light Green Conclusior Acknowle¢ Light Blue | Literature Light (Drab ARTICLE 1 Yellow ON CH Te (9 Prat : Introduct: ei Back Changes 10M Je.'Te | External |” ) AS VeLSi ret acca tides SEM arata taal eis erat sleteis a oie) ote lac loll al ai sValaia) arala)aela\e) sleraia eve arersnersereret we ATIAVICA et aeOle SUDSLLATUIITCS <<) 1<:610, 6.0, oo Do gD DAnGosaO man ti: 43 PYTOMOMDH ses Ayes ees cloves lata cetera eet rere pets 44 Generalized pupe with maxillary palpi.......................205 44 Wh (sy 0y bo f- +: ee ei EE aS Min See EA 5,4) 5-c105.9 Dich eS GAIEIO SAO - 44 POOKIE sae nenierns teoeteeiemisteleienienice ee ee inio OMe Oe oa OO} 45 CTOLO PHT ee A. Las bv. wlterel. ow ie sotecetoune eb ck rire) ar cite rete ean cee feu eta oa : 46 PMLA sls ids Fs ce hse Ae vette oe eee oe cP eee) eres ty FRCVIOGINIGR: i. 5 od ebaeere wtdvsid devpit deletions ibis cio on preter eR nedle tay aCe 47 WOPCTIOIDEAs oop 57k mye tisieressreseaste sale te Peaielstsi ovals evousie tefane iene ee peheeene 48 oN C2 ee EEOC OR ICR ia CIO CLG OE SOROI oO Ucn opic-cyo 49 TOYVtTICOIMEAs 52s: shsieics:ore,0ie tes (00) Sie ars © 7h 51516, 810)» w5 0 (0, ¥ (a sn epee eet eee 51 1D yhaentiee eno qumoomoumoor con CON CO FOO oEOm@Ob Oo sie odogec 52. OLS ren bid eye aleie aver cvelelasetois ate ln) ale) veeqo pein fer iofetle thiolate stats ister as > siapes 54 TOTLTICldey hacia Hd cao he cece ecleanehe eee oes Ph) 56 SPAT GaNOvHdesy | «5.5. Ge ei. chahe.ey ani seeps boas eva ionaladene ehatstatsi eek. Stee eee 57 Gracilarioided +) 1.5.20: 4o. cece ace Ble ae oe eae ik eae : 58 Nepticulide ..... WSs diabaids b-stesaln' sca ore/eie la SYevarie Bie fe Ree eaehcts oleh aera 61 fen ozeli dees \<\x)< ate c-0 ss svetsiavore lovee ateeps) she ions ne iets folel teat ates eaeene ete tee 62 PPUSCHOVUTGE. | 55 jesars clare aye ol tiole o's vedas @ isieys mistelaletanl a anise rete eee 63 Buceulatrigidas™ /- iar sys chcist oreteceiols\eheve ace yeusretotere ens etalon 64 TisyONetiidee< 502 discs craps iets weve Glee iw side, bore Sister ee STOR Ee nen 64 Gracilariidse > 38 UL aad Aiea een Oe eee 65 Phylloemistidaey/ ssi 5..ysre.0.4:c,srssaversrave visit 01810\4 sl vrar eles oleic leet aero 68 Specialized pups with pildfertsi ye 2c. «cists nuciareietlete encom ctenniate Messe ste 2 (i) PY VAG OUdea) © \eb:0 5 fore corsToie oles, dive [elordse lm inteyersin re se aeRO eee 69 PLSLOPHOLId as, | sites wroyes ote\acepatece love corel ccxcotetor tia STP OreT MIR eee een 70 PATTOV EGE «ids! ols (e lelelpiele's leleissole'el efoto late lelatslslcleletter cle lereeieiten cen iaketelavers 71 Py LG ie a Fo. siete ves sore vagosevsvs:e.a. s Ki ohesnve (otetslavetelere etetettes ere nO ere omer tere @ 2 Papilionoideay<,. A GUC DODUTHEC ROSIE aoeiniog tr 106 MN CarT RIED AIA Gah May ehdh Go cier stay avast ate) oleh chal aYa) Nsicucvaveleielas sain 4 ala eoicpataralarmleiae eis 107 iSight! SERB GpE 6 ASR COMn DE ODED Ee CODCOD ADCO MOR Crm a Reo i 107 RSGINLIDI OCA terete race rere stateteaaiecehsiete ieWeisie eutie sare (ele). e¥s)a eiehia) oy pliv' ele aytarsvaleynl'acwie 119 PPR P YA Ted Cee aya) cin, setlist tials nis @) aie ekaln\addimtaloyarw sve! eval ers e(aielay ale, tidiia.s aile.ete 121 ESEDEED ESC CO1ET Ocenia ebayer avalaate(sic fakes onais/aY'olalata ats ctcls ards ataltaeyel o)cirisa's)'scsin'e) ale - 1238 ILE yeep ED “5 Gang HOON AUOU ODOC CE PU On ICH OROCCUBGEOCITaT aS 123 LGR. 3A SAAB ROObCnOnb GAOdo Moca Ono cueon Gorres 124 MT EOLON LOT Gamera apscidie lc «1 Ss erale/e ihe iwisipiedsicrelere as \siselelaia\> e7eratalaie'aivere 125 OR ORE TOMER ita eat atac islets ei'ctsin ovolelevahsys, stoic sve siete ale) etuial aperaimlavelapeidiers 126 DOU CEE Chee este cect eiiey alicia, a oe See IS SEER SAS 227 FYOXATOMMIMES Syocshavelerei ci skcrioteie el wee tele els er Teles Vote ea tee eRe eee 232 TrichOCOvimee os certs s cieicvsusess oi eeveperere ae o\Sceratefats es, ARAM Ep ee etecelere 234 Papers on the Biology of North American Limnobiide..... 238 ImAvel tol ereiol: ny ono doiniaoD bana oAaaosd doc aad oaqsousohoupoAS 238 Pad ah is) 10Gb Ue NOS OOOO T FOOD OUR COO S oa gdoowale 241 vii ACU ME EDIT CULE us «nate ailersiint ciel silel ous) vcsiadeleahanaialave eiaid fale sl esp sVerexe| 6 rc'e «les EM CCHS MELON COD, |< oFs\ershenene hater ats ievel ela) oe) eilolsl’er ei beta Cait genet sanchez 2s CRTC UML ec gists ayer eae eh ele erel oteial s) alelajereia eh ererorsiere aay) aside) + lays UMHS CHES IAT LTEL 1 P )eliefctatettetete nian haverenc vain ae wale’ oe.e weystanereve, ekecoje.cl raya eee eae 340 Principal papers on North American Stratiomyiide........ 346 Ry lopharideny’ aw sey ks a eke Saad ae ae San AG COCTIOMY TG arse rahe i «s/o 0!0 d.bioce Ssainlsy erevn/ever clara alte Cletalt Miers Eee 351 ACANthOMeTIGB vas. bisyc env sd dae alelaa erento eee Rates Getogies - 354 Tabanoidea ......... As hale Ze, byaveia ocatnte, niet Ales ote are een eee 354 ADA ee) soy sb oi 3 ca 58.0 o.a.8,5/ai5yh at avalon Os) eusieenreersh eee tstene Renee ene eee 355 Principal papers dealing with the biology of North Amer- Team)! Tabanides i. .54,16.3/80's(e eeisia hele (la eute eeaeaetie ree 361 DSP UL SS oo 2 )isefeyeelaie.nyei sieves wrt geireieiera oper ok ott cael ayehe tele Mrs ata ret eae 362 (Chedieliceh SonhomaornonU cao MoD obtonconendacatina non saiiocas sos s 368 INGMIESEMINTE 4.4 lata oie'o eve 0.o: Oe ie slays. © ee atteleds MioletcENe ee aRSTA nee 368 (Oh GE eB aeEe Iso ree netcrin a nC petooae dota oad or 368 Papers on North American Cyrtide.......:...........0.-- 369 ASTOIMGR peace a cicdcined ee ee adh oie SSC at an coe eee eee 369 her ie ee Ae eA Re Om AOE bse Aceon oc 370 APPOGCTIODR tie Src sie sraiiietereleiw'ie0 Wels whe Wie nie eral ete Mbahe see ei ee 373 ASTID RE ssscccydris Soreodisne: © Gove ore detelleie, w ris lets slots eleleVeleikelerse ie rennetete ace 373 BBOMRDY LUT 2s soni a caswse fata Ge fase ncn ate sce are ecaye satelite tera elenensuenerays eerie vanele 389 References to Descriptions of larve and pupze of North American BOM PYLE oe sic cus eve mi eletetere eloletettle tn leseteretctereloratene 395 THEPEVOIMEA, ~ die). slic cele ore, dip teteas te vole ih’altesunteye lofeteneeste tele siay sae tone eeatermenee 396 MMA b Mie aco mot doe os pocodapabalodorgscoodadecasocs 396 SCOMO PINT Wise clots) sheralsbole laleinietetoteuataeraiets vie. a'e-¥.p whe wl aheboualetstenaterete 398 Tribe OrthoGemyia's sicc israel scoisreis aceieter « evensinstatolsieya alain tetels fave ete neeaneneye Tey.s 399 Fim pididoided), os) sc ss.s1ec/ecress as pcernue oleie avsioisyoy svcteda iW lataha ele ladenennean item eis 399 1p Ot Wee erMBens HEME EDD iar SHOONGA DRO Gooo Tp aoo DS 400 Papers on the biology of North American Empidide....... 403 DOlichoPodsdss oa. terciovnvi vies «coset fle ao, dea, arepacolaleeae can CReeeene Merete le Tetroerera 403 References to papers on the biology of North American and Buropean. Dolichopodider:. 55. \aic se w civic ules steve wiv alee lene 406 ——_—— ix ARTICLE IV. THE ZYGOPTERA, OR DAMSEL-FLIES, OF ILLINOIS. paar BY PHILIP GARMAN, PH.D. (16 Puates) June, 1917............ 411-587 MFEITESSERTEC HACV EDOM (oe tceysticvecs ae ).s7e 0s Sep aieltev ahs ere ect e evele said che wale ale, Sorsem eagle os 411 Acknowledgments ..... Heo teielertenatacets rats, 2:6 kala te sie,aisieralele Mais aes asretae)s 413 LOT TIGER? o.dg4 Bintod CO RIORIEO DEEL. D OCCT ACOIAEIOIAEIE Orica ena Ie eae eee 413 SERIE EM Merete eter ole na lcneretaeietiic fb a eicichevse-sietsis, Ws s-vi8 she eis sale eye wise ey ere 413 ERIM MMR eer a esc cis claro. sc: crayelefeabataiate.slehene Giese. savaara ee s.5.due(oa ga more ABE SOGDC 423 RREMETIM EOI Va cTCO LADIES © ci,c ther iaetaicversictatnete\s: oats 6.6) tieldave Sic lsleuwiely eivjeidtave 4° 438 GIES conc 000 Ae SOIR en SER U/L ERR COI IOAN En TNIC EET eae 438 ESD ORFERNS SUMMER Cte cei): 0: < va OPUES ale oe: ce: Snelesettyenatcdse tev: erdisre e-bot'S. « @ieysis eielevese 439 PRLS MPT co Ora sAiav cs eta tecete war aia eiatclevareya arse newe a,cla-a Mu aropalesoareiae es 444 EMER LODUmG TENE IY PODLELAR tet cc8 eyes alors vis deegss bey eee be tee baweee 446 SECEDE GLO LVS prover et MEET Ta) ais oooh eet es Shore, oti sic avnne easel hele Lerock ateisuche owes 446 LTRS RSLS. Fee Glcrexe. c00 o GPee EERIE CRORES Ec ERR eRe a 450 Phylogenetic comparison of Zygoptera and Anisoptera............ 453 eS eee PERRIS cle Sieh chai! ose ate aes einer aisle eiente, wees) wtalatia 612 Sai Seale ad 454 PRINS IMIR tenes ois yetKia ova es Sie calera. dae aaii's asthe ow Minted ddyewigee ve 455 PSA UT UENO ars) oA arene lavas) ais wi iciore Se iele ees Stayenendea yak idaseteretanstyeny exe 457 Bee Rae e tad LU LEDEEMME Pete ote ete Pattee cTeNTs oe ciel Mates eile a al avsval seine tates each wives 464 PERMSRO LIS EAS MMNEE oR Peto acl ce rete fe iatcte aiardueia: seth oon acdsee ols aabna Susie vedios Vee 466 ES EDIGRINEDS oc 'o.c 1b toto BODO LOT OR aeRO or DE aE ei eon a anERae 466 MOYER ELE SOL ITT A ene reese Eye's shdiriond die wleretoeie 499 PEST ESRecl Nt Vater anette iuatct eke at shenayeusyc,svaud wiatsiaie gave. a"Grage-atd ade eraiaca.econenaere 577 INRALERITEL EIS 3A, Baers eer Ae ec I ee HE CCRC Oe MISO DO OMS MMe C 578 JAVTETUNES: Aye See BROOME CD CEES SONS OREO Ee ere ee Ga ea em eet ae 580 Index to genera and species............. AAP SHOE ORDER OT tite 584 Abbreviations used in lettering plates... ... ...... cee ee eee eeeees 586 ve “ et a ee ae a . ait Met: ERRATA AND ADDENDA Page 5, first column: line 2, for Sheper De read Shepherdia; line 11, for americana read americanus. Page 9, line 5 from bottom, for XVII read X. Page 42, line 4 from bottom of key, for Pyromorphidae read Eucleidae. Page 73, line 7 from bottom of key, for or read and seldom. Page 100, just below key, insert as follows:— The following species were examined: Lophoptilus eloisella Clemens Laverna brevivittella Clemens Page 107, lines 8 and 9 from bottom, page 108, line 10 from bottonr, and page 110, line 10, for Cucullianae read Cuculliinae. Page Page Page Page Page 110, 112, 129, 131, 158: Polia Page 170, line 4, for Strayiomyiidae read Stratiomyiidae. Page 243, line 8 from bottom, dele Polia. line 19 from bottom, for Metathoracic read Mesothoracic. line 8, for never read sometimes. at end of second line insert Paleacrita Riley. first column, after Paleacrita, 127, add 131; second column, after dele 110. line 2, for alternata read alternatus. Page 307: line 5 from bottom, for with read and; line 16 from bottom, for Homeodactyla read Homoeodactyla. Page Page Page Page Page Page Page Page Page 314, 321, 324 370 428, 461 478 519, 528, line 15 from bottom, for Cecidomyiidae read Coenomyiidae. line 12 from bottom, for Stratomyia read Stratiomyia. line 6, for pantherina read pantherinus. line 18, for Hmpidoidea read Empididoidea. line 8 from bottom, for Mesnotum read Mesonotum. line 10 from bottom, for Aeshnide read Aeshnidae. line 13 from bottom, for vigilas read vigilaz. line 2, dele side. line 10, for caruncluatum read carunculatum. ’ i te t ‘ 4 : ; ne . te ll . s ' ' “ i ! io ! r, . , } t a > i, r i ‘ ) Pee a ji oe oad ae ee an fi er AN), i , ‘ , i ny j t ™ hy he oes ee ar) , We \ Tia ae | > ih ag? “i ~ aay: pe v t : i Tay i f , vy. i pov et wet es! -* ee AL “ an tii ib hek Ler = ary , re t * H ] cay wal 4 of y ey a ‘ - aia biel 7 ae ve ae 48 »e | hdl: eth 4 oti C Elmhurst “nd y BS Hnaaeive: iiside™ 83 tern o a oan wle cea alot ae wy, firm Springs. ° \> ‘ Frank \ Tehigan GLENCOR, ILLINOIS, AND VICINITY ArticLe 1—The Relation of Evaporation and Soil Moisture to Plant Succession in a Ravine. By FrED THEODORE ULLRICH.* INTRODUCTION For some time geologists have surmised that differences in the evaporative power of the air and the soil-moisture content account for the succession of vegetation that accompanies the physiographic changes in the development of a ravine. In order to determine whether or not this surmise can be supported by experimental data, this study was made during the summer of 1913. The ravine selected for investigation was the McLeish ravine, which lies in the south- eastern part of the beautiful village of Glencoe, about sixteen miles north of Chicago. It is mapped in the Chicago folio of the United States Geological Survey as a part of the Evanston-Waukegan re- gion. The general geographic features of this region are the moraine plain or rolling upland, the present shore, and the lake plain with its associated beach ridges. The rolling upland which constitutes the larger part of this area is glacial in origin, consisting of the usual glacial drift, clay, sand, gravel, and boulders, and rises more than sixty feet above the level of the lake. Since the ice sheet retreated, some of the glacial material has been reworked by rivers, waves, and winds, and thus is stratified. The heterogeneity in the composition of the drift and the resulting differences in the resistance to the forces of corrasion, and the great elevation of the upland above the level of the lake have furnished and are furnishing excellent conditions for the development of ravines. Of the many that have been carved in this upland, the McLeish ravine, although one of the smaller, may be considered a good representative. PHYSIOGRAPHY OF THE McL&#ISH RAVINE (Plate XVIII) It would be foreign to this study to give a complete exposition of the geology and physiography of the ravines of this upland region. Such a presentation is given by Atwood and Goldthwait (’08). How- ever, an intelligent appreciation of the method and results of this study requires a brief description of the location and direction of the *Accepted by the University of Chicago for the degree of Master of Arts in Botany. 2 courses of the ravine and its tributaries, the probable origin of the ravine, and its present physiography. The McLeish ravine is formed by the confluence of two gullies, the heads of which, if measured in straight distance, are each about 2000 feet inland. From the junc- tion of the two gullies the ravine has an almost easterly direction for about 1500 feet, until it reaches its main tributary from the south, when it continues in a northeasterly direction for about 800 feet to the point where it empties into the lake. From the south, in addition to the main tributary, the ravine receives a number of small gullies... Physiographers have summarized under three heads the succes- sive stages in the cycle of the development of such a ravine as the one here considered: the V-shaped valley, with slopes normally con- vex; the U-shaped valley, a stage of development where detritus descending the slopes is not all carried away by the stream, and con- sequently the valley is being widened faster than it is deepened; and, finally, the valley with a broad bottom, in which transformation is affected partly by erosion and partly by deposition i in the ravine. The tributaries of the McLeish ravine are mostly in the first stage of the cycle, while the main course of the ravine shows that it is passing trom the V-shaped stage into the U-shaped stage. It is altogether likely that this ravine had its infant development accelerated by swampy depressions in the upland near to the lake. Such swamps or marshes within reasonable distance from the head of the cliff of the lake shore would, through seepage, make materials between them and the lake shore so mobile that the head of the gully would work inland with unusual rapidity. The influence of such de- pressions in ravine formation can at present be seen in the vicinity of Glencoe. In the weekly visits to this ravine, the physiographic changes due to weathering, wash, and lateral corrasion were decidedly noticeable. Some of the records made at the time of observation read as follows: (1)—during a heavy rain—small streams of clay are flowing leisurely to the bottom of the stream; (2) it will be only a matter of a rela- tively short time when two large hard-maple trees will become so undermined by the streams caused by heavy rains as to fall across the channel; (3) a large slump of clay has been deposited at the bottom of the ravine during the preceding week, due to the undermining action of the stream and to the percolating of the water through the soil above the cavity; (4) in following the ravine, from the point where the main tributary enters, to its mouth, a gradation of detritus ranging from boulders and cobblestones to sand is passed (PI. I, Fig. 1); (5) the waves of the lake usually maintain a bar of shingle and sand across the mouth of the ravine, which results in the formation 3 of a pool of water which gradually filters into the lake as more water is brought down the ravine; (6) after heavy rains the channel is invariably reopened by sweeping the materials which form the barrier into the lake. This gives some conception and appreciation of the force of the current as an active agent in modifying the physiography of the ravine. These statements indicate the dynamic character of the McLeish ravine. SUCCESSION OF VEGETATION After this brief consideration of the geographical and physio- graphical features, we may now turn our attention to the vegetation. Cowles (’o1), in his “Plant Societies of Chicago and Vicinity,” calls attention to the fact that the slopes of the embryonic V-shaped ravine, after they attain sufficient stability, develop a carpet of luxuriant vegetation. He says: “In a comparatively few years the vegetation leaps, as it were, by bounds through the herbaceous and shrubby stages into a mesophytic forest, and that, too, a maple forest, the highest type found in our region.” This: quotation describes admi- rably what has taken place in the greater portion of this ravine and its tributaries. A somewhat detailed examination of the summer and fall flora of the ravine showed that the slopes of the gullies leading into the ravine (Pl. I, Fig. 2) were nearly or quite devoid of vege- tation, with the exception of some mosses on the north-facing slopes. A wash or gully near the mouth of the ravine, comparable to the head of a ravine working inland, had rather severe conditions for plant growth in the upper half of its slope. Owing to the extreme exposure to light, wind, and heat, and to the absence of humus in the soil, only a few of the xerophytic pioneers succeeded in establishing themselves. Near the foot of this wash a more or less stable minia- ture plateau (Pl. II, Fig. 3) was formed. On this, during the latter part of the summer, there was a great variety and profusion of asters,—one of the most pleasing sights in the ravine at that time. The slopes with mesophytic forest vegetation, with its usual undergrowth, constitute the most general feature of the ravine. This mesophytism in a ravine is regarded by ecologists as only temporary. After the vertical cutting has reached base-level, and as lateral cutting reduces the inclination of the slope, removing the humus and increasing the exposure, there is retrogression from mesophytism to xerophytism. This tendency towards xerophytism is checked through the develop- ment of vegetation, which finally results in the establishment of the permanent mesophytic climax of the region. In the ravine under con- sideration one of the strongest features showing the significance of exposure in the gradual retrogression from mesophytism to xero- 4 phytism was the paucity of tender mesophytic forms and the less luxuriant vegetation in general on the south-facing slopes. In the early spring the north-facing slopes of the ravine were covered more abundantly with the various plants of the vernal flora and certain mosses than the south-facing slopes. PLANTS OF THE RAVINE AND THE OAK UPLANDS The plants of the ravine are recorded under two more or less | distinct physiographic areas; the xeromesophytic slopes of the gul- lies (Region 1 of the table) and the mesophytic slopes of the ravine (Region 2). Some of the plants of the oak uplands (Region 3) are listed, to emphasize the differences between it and the ravine. The vegetation of the oak uplands may be thought of as either antedating or succeeding that of the ravine. The vegetation in these three suc- cessional regions is not entirely distinct, but even a superficial ex- amination of the following list shows striking differences. As this study covers only the period from June.21 to October 18, 1913, much of the vernal vegetation is omitted. In the examination of this list of plants it should be borne in mind that the vegetation of the slopes of the gullies and ravine is noted much more completely than that of the oak uplands; that the in- dividuals of certain species were generally more numerous on the slopes of the ravine than on the slopes of the gullies; and that in certain localities of the ravine such plants as Osmorhiza longistylis (Pl. III, Fig. 5), Amphicarpa monoica (Pl. Il, Fig. 4), and Aralia nudicaulis (Pl. IV, Fig. 6) had developed pure growths to the ex- clusion of all other species. Furthermore, and most important of all from the standpoint of this study, the list of plants for any of the three regions must not be considered as static but as dynamic in char- acter. As already emphasized in an earlier part of this paper, with the changes in the physiography of the ravine the vegetation of its slopes tends to assume a xerophytic aspect, but only until stability of topography favors the succession of forest types, whose climax in the Evanston-Waukegan region is essentially the same as that of the mesophytic slopes of the ravine, the hard-maple type. An investigation which is to determine whether or not the differ- ences in the evaporative power of the air and in the soil-moisture content account for these successions and the minor differences within each of the areas where plants have been listed, involves, as the first step, the selection of certain typical stations—stations significant from the standpoint of exposure and ravine development; as the second step, the measurement, at regular intervals, of the evaporative power Species Region 1 Region 2 Region 3 Species Region 1 Region 2 Region 3 [Trees and shrubs] Juniperus communis Sheperdia canadensis Thuja oecidentalis Populus grandidentata Prunus serotina Salix glaucophylla Elwagnus argentea Ostrya virginiana Lonicera Sullivantii Tilia americana Ceanothus americana Acer saccharum Carpinus caroliniana Juniperus virginiana Fraxinus americana Hamamelis virginiana Viburnum Opulus Cornus alternifolia Cornus paniculata Cornus circinata Ribes Cynosbati Psedera quinquefolia Menispermum canadense Celastrus scandens Rhus toxicodendron Quercus alba Quercus rubra Quercus velutina Quercus macrocarpa Carya ovata Corylus americana [Herbaceous plants] Rudbeckia hirta Fragaria americana Melilotus alba Equisetum arvense Equisetum hyemale Pedicularis canadensis Echinocystis lobata Krigia amplexicaulis XXXX KKK XK K KX xX XX XXXXKXX XX KK KKK KK KKK KKK XK XXKXKKXK KX Saponaria officinalis Polygala Senega Aster levis Aster multifiorus Gentiana quinquefolia Polytrichum commune Helianthus divaricatus Asclepias syriaca Desmodium rigidum Monarda fistulosa Catherinea undulata Mnium sp. Anemonella, thalictroides Adiantum pedatum Botrychium virginianum Asclepias phytolaccoides Thalictrum dioicum Uvularia grandiflora Mitella diphylla Hepatica acutiloba Trillium declinatwm Viola cucullata Galium triflorum Anemone virginiana Cryptotenia canadensis Osmorhiza longistylis Amphicarpa monoica Impatiens biflora Allium tricoccum Smilax herbacea Aralia nudicaulis Aralia racemosa Desmodium grandiflorum Polygonatum commuta- tum Sanicula marilandica Heracleum lanatum Solidago canadensis Convolwulus sepium Sanquinaria canadensis Helianthus hirsutus Brigeron philadelphicus Erigeron ramosus XKXXKXXXKXXX XXKKK KKKKKKKKKKKKKKKKKKKKKKKXK XK XXX 6 of the air and the soil-moisture content at the stations selected; and finally, as the third and last step, the interpretation of results. LOCATION AND DESCRIPTION OF THE STATIONS In this study seventeen different stations were established; fifteen in the ravine, one in the oak uplands, station 16, and still another in the open uplands, station 17 (Pl. IX, Fig. 15), the vegetable garden of the McLeish estate. The fifteen stations in the ravine were lo-- cated, speaking generally, as follows: Station 1 (PI. I, Fig. 2) in an © embryonic ravine; station 2, in a portion of a ravine, with lateral cutting delayed, forming a miniature clay cafion; stations 3 (PI. I, Fig. 1), 4 (PL.-IIl, Fig. 5), 5 (Pl. IV, Fie: 6), 6 (RE V, Fisssy and 7 (Pl. VI, Fig. 9), in the part of the ravine with the mesophytic forest vegetation on the slopes; stations 8 (Pl. IV, Fig. 7), 9 (PL. VII, Fig. 10), 10 (Pl ‘VII, Fig. 11), 12 (PL 1, Fis’) ano (Pl. VIII, Fig. 12) in a portion slightly less mesophytic than the preceding; and stations 13 (Pl. VIII, Fig. 13), 14 (PI. II, Fig. 3), and 15 (Pl. IX, Fig. 14), on the slopes of a wash or gully near the mouth of the ravine. The specific geographical location of each of these stations in the ravine and its tributaries and also of those in the oak and open uplands is shown on the surface map (Pl. XVIII), while the angle of slope, direction of exposure, and soil and vegetation char- acteristics are enumerated in the following tabular summary. The “wilting coefficient”’—a term used by Briggs and Shantz (’12:9) to represent the moisture content of a soil corresponding to the wilting point of a plant—for various soils in the McLeish ravine was correlated with the soil-moisture equivalent by an indirect method devised by these authors (’12:56-57). This coefficient indicates the limit of soil-water content above which growth must occur, al- though plants will live and continue to draw water below this point. In listing the dominant vegetation of each station the emphasis was placed on the herbaceous forms and the seedlings of shrubs and trees because they are a much better index of present ecological con- ditions than the mature trees. MEASUREMENT OF THE EVAPORATIVE POWER OF THE AIR The instrument that was used to measure the evaporative power of the air in the different stations was the Livingston (’10) porous cup. The structure and operation of this simple instrument have been so well set forth by the inventor and others that have used it for scientific purposes that an explanation of its management would be l~ SNOILVLG ONINYHONOOD AUVNWOAY FAlLdlaosaqd a 908, 0°06 '9T sjuetd A1eqMeiyg FOL [los mepaes pooy Gasman -1us en LT ey 2 ; snuny, Chins pees ince ik ede td v08 yt Lvp sroptnog Spoos AZO | ins aaery a "° ; Q : enya Tea peony 0 BE'6 wON Tet Key AWTS MN do} t@8N | “soa zo yoo | SE ae ; ‘dd : aye 1804 a0 TE'8 EAN 6 PIL Avo Apueg a AN N ®IPPHN -e1d [rewg las 0°) €6'8 asuadun wnjzasind ay 01 Avo Apueg “M'N 400, = €I 00 €6') euoN L°Sr 6 WOIye}s sB omRg ‘Sg doy 1eaN oP ral 0°0 FL'G povouow od.imoydup 8°31 6 WOT}eIs sB oulRg eIPPTAL 60S IL 2) 07 sosso ; aaoqe se ome . do} xa aordroerd 09 W SSL o Ss N } VON Jo 400g 4V oT “: q - sarqqed Wyrm “ o'd 9€'9 pgopit, v91y0da FT SéT poxtm sv Apueg N STPPON 09 6 Fi, ; worye4 8}001 : “24S BAaoge O90 19S |-e80a snosdeqiey ON 16 Aq poayyeut [tog N 00d esta ydniqy 8 Ay : pq sno1ang) 0 en a0 92 = \nupwmbna sniadvung 8 anumy, Aqedoupt a's doiase BL a L DUDILAWD = sSNUeD. *o°0 TSG ROAM Gate cloak 6 LT ureo, pue Avlp ‘aS SIPPTAL 009 9 2°0 19°9 synmopnu DYDLE POL weol yor, "MN doy 1eaN oGS c '0°0 86'P syhysybuo) vzvy10wso €'8t uBo, World “MN STPPT 009 id ophiydyp operat yoy} 00 GLP paongiay rolls 6 LT ‘ur g ynoqe ‘snur “AN JOO" = € UNLDYIODS LOK ny pue untaniTy snuny, O° 12'e ssom jo sorody SSL ueyy Avpo a10ur ‘aN doy reaN 008 Z ‘snumg pue Avip eyrga A1OpAOT 0°0 FPS euON —= ‘soqqqed = yy Ta “M 0077 oh T pextu ‘Keto Apueg é “ quaroTye0o [tos jo edojs yo edoys mOTye38 dose Apep “ay |) aed queqpmog “Sanit 6 royoereyo [e1auey) ernsodzgy 101} 80077 jo osuy jo "ON re 8 superfluous. The writer is aware that the instrument does not register with complete accuracy the evaporative power of the air when there has been precipitation during the period for which the measurement is made. During a rain, indeed, there may be a flow of water into the bottle. Drizzling rain for a long period will cause more water to enter the cup than will the same aggregate precipitation if due to a heavy rain extending over a short period. Since the results in this study have only a comparative value, the entrance of water into the bottles does not vitiate the results. This fact was first pointed out - by Brown (’10) and later emphasized by Fuller (’11). In the handling of the instruments for scientific accuracy, in the selection of the intervals of time for reading, and in plotting the results, the writer had the constant advice and suggestion of Dr. Fuller, of the Department of Botany of the University of Chicago. Without his help many of the difficulties would not have been so readily over- come. All the instruments were standardized before being placed in the respective stations, and restandardized at intervals of six to eight weeks. By the coefficients thus obtained all the readings were re- duced to a common unit. The first reading was made on July 5, 1913, and weekly readings were made thereafter until October 18, when the last record was made. Thus the investigation extended over a period of 112 days. Very few of the instruments were molested during the entire season, and hence the regularity of the results for each of the stations is rarely interrupted. ‘These results are expressed as the average daily loss for the weekly interval between the readings. These results are graphically represented with the weekly intervals as abscissee, and the amount of daily loss by the standard atmometer in cubic centimeters as ordinates. INTERPRETATION AND DISCUSSION OF RESULTS 1. The graphs in Figure 16 (Pl. X) show that the average daily rate of evaporation for the weekly intervals was almost uniformly greater in the embryonic ravine than in either the narrow or broad portions, and greater in the broad than in the narrow. The average amounts of evaporation per day for the entire season at stations 1, 2, and 3 were 5.44 c.c., 3.27 c.c., and 4.75 c.c. respectively; that is 2.17 c.c. per day greater in the embryonic ravine than in the narrow portion, .69 c.c. greater in the embryonic ravine than in the broad portion, and 1.48 c.c. greater in the broad than in the narrow portion. In terms of percentage the rate of evaporation was 66.3% greater in the embryonic than in the narrow portion, 14.5% greater in the embryonic than in the broad, and 45.2% greater in the broad than 9 in the narrow.* Since all of these stations are located near the floor and represent successional stages in ravine development, the data suggest a movement from moderate moisture conditions in the em- bryonic ravine to greater moisture in the narrow portion, with a reversion to slightly drier conditions as the ravine changes from the V-shaped to the U-shaped type. 2. The graphs in Figure 17 (Pl. X) show that the rate of evapo- ration was only about two-thirds as great at the foot of the northwest- facing slope as near the top of the same slope, and that there was little difference in the rate of evaporation for the greater part of the season between the foot and the middle of this slope. The average amounts of evaporation per day at the foot, middle, and near the top of this slope were 4.75 c.c., 4.28 c.c., and 6.67 c.c. respectively. The graphs in Figure 22 (Pl. XIII) show similar results; the amount of evaporation per day was 2.33 c.c., or 63.4%, greater near the top than at the foot of the north-facing slope. The rate of evaporation at the middle of this slope was, for about the first two-thirds of the season, nearly the same as near the top. The graphs in Figure 19 (Pl. XI) show simi- lar results for the opposing slope, the average amount of evapo- ration per day being 4.75 c.c., 5.51 c.c., and 7.6 c.c. respectively for the bottom, middle, and top of the southeast-facing slope—2.85 c.c., or 60%, greater near its top than at its foot. A similar series of stations in a less mesophytic portion of the ravine exhibit a similar set of con- ditions to those found in the more mesophytic portion. Here the rates of evaporation at the bottom, middle, and top of the north-facing slope (Pl. XIII, Fig. 22) were respectively 3.67 c.c., 6.36 c.c., and 6.0 c.c., while for the south-facing slope (Pl. XIV, Fig. 24) they were 3.67 c.c., 5.74 c.c., and 7.93 c.c.; that is, the average amount of evaporation per day was 4.26 c.c., or 11.6% greater near the top of the south- facing slope than at its foot. The graph for the daily rate of evapo- ration for weekly intervals at the middle of the southeast-facing slope (Pl. XI, Fig. 19) is diagrammatically between the graphs for the evap- oration at the foot of the northwest- and near the top of the south- east-facing slopes, and likewise the graph for the rate of evaporation of the middle of the south-facing slope (Pl. XIV, Fig. 24) is between the graphs for the foot of the north- and near the top of the south- facing slopes. As already pointed out, the rates of evaporation for the middle of the northwest- and north-facing slopes (Pl. XVII, Fig. 17, and Pl. XIII, Fig. 22) were not intermediary between those at the foot and near the top of these slopes; the coincidences in the “*In the computation of the percentage rates the smaller of the two numbers is always used as the base. 10 rates of evaporation at the middle and foot of the northwest-facing slope (Fig. 17) during the early part of the season might be attrib- uted to the fact that, the instrument at the middle of the slope was almost surrounded by a dense growth of Osmorhiza longistylis (PI. Ill, Fig. 5) ; and the slightly higher rate of evaporation at the middle . than at the top of the north-facing slope during the latter part of the season (Pl. XIII, Fig. 22) might have been due to the unusual expos- ure of the middle of the slope compared with that at the top (Pl. VII, Figs. 10 and 11). Further, the differences in evaporation on different’ parts of the northwest- and north-facing slopes (Figs. 17 and 22), are less than on corresponding parts on the opposite slopes, and thus a station between two other stations would give less striking differ- ences. In summary, the graphs in figures 17, 22, 19, and 24 show that as the northwest-, southeast-, and south-facing slopes are as- cended there is a graded rise in the evaporative power of the air, the southeast- and south-facing slopes showing this more decidedly than the northwest- and north-facing slopes. : 3. The graphs in Figure 18 (Pl. XI) show that the rate of evap- oration was generally greater near the top of the southeast-facing slope than near the top of the opposite slope, the average amount per day for the entire series being nearly 1 c.c., or 13.9%, greater; the graphs in Figure 20 (Pl. XII) show that the rate of evaporation was almost uniformly greater at the middle of the southeast-facing slope than at the middle of the northwest-facing one, the average amount of evaporation per day being 1.23 c.c., or 28.7%, greater; the graphs in Figure 23 (Pl. XIII) show that the rate of evaporation for every weekly interval was greater near the top of the south-facing slope than near the top of the opposite north-facing one, being 1.93 ¢.c., or 32.1%, greater; while the graphs in Figure 25 (Pl. XIV) show re- sults at variance with those in Figure 20 (Pl. XI] )—a greater rate of evaporation at the middle of the north-facing slope than at the middle of the opposite south-facing one. This was undoubtedly due, as be- fore suggested, to the unusual exposure of the middle of the north- facing slope, which was subject to less shade than any of the other stations in the immediate vicinity excepting the one near the floor of the ravine. The results shown by figures 18, 20, and 23 indicate a greater loss of water and-consequently drier conditions on the south- east-facing slope than on the northwest-facing slope, and likewise greater loss of water and drier conditions on the south-facing slope than on the north-facing one. This difference in evaporation is un- doubtedly due to the fact that the incident rays of the sun strike the southeast- and south-facing slopes more nearly at right angles, which means greater absorption and radiation of energy on the southeast- 11 and south-facing slopes than on the northwest- and north-facing slopes. Furthermore, this difference tends to explain the presence of tender mesophytic forms on the north-facing slopes of a ravine dur- ing the early part of spring, before the development of leaves on the trees, and their absence on the south-facing slopes. 4. The graphs in Figure 21 (Pl. XII) show that the rate of evaporation was greater throughout the season in the oak uplands than near the top of the northwest- and of the southeast-facing slopes, being 2.11 c.c., or 31.6%, greater per day for the entire season in the oak uplands than near the top of the northwest-facing slope, and 1.18 c.c., or 15.5%, greater than near the top of the southeast- facing slope. The graphs in Figure 26 (Pl. XV) show similarly that the rate of evaporation in the oak uplands was generally greater than near the top of the north- and south-facing slopes, the average daily evaporation for the entire period being 2.78 c.c., or 46.3%, greater in the oak uplands than near the top of the north-facing slope, and .85 c.c. per day, or about 10%, greater than near the top of the south- facing slope. This indicates that the upper portions of the south- facing ravine slopes have an evaporation very close to that of the oak uplands. Indeed one might expect a greater evaporation near the top of the south-facing slopes than in the oak uplands, due to the in- fiuence of slope exposure. Further, the differences in the average amount of evaporation per day between the oak uplands and near the floor of portions of the ravine were 4.03 c.c. and 5.11 c.c. In summary, all of the preceding statements show greater evaporation in the oak uplands than in any part of the mesophytic portion of the ravine. These differences may account for the more xerophytic aspect of the vegetation in the oak uplands than of that in the ravine (see p. 5). The graphs in Figure 21 (Pl. XII) and Figure 26 (PI. XV) further show that the rate of evaporation in the open up- lands, the strawberry bed, was nearly twice as great as in the oak up- lands or in the most xerophytic portion of the ravine, the average daily rate for the entire period near the top of the northwest- south- east-, north-, and south-facing slopes, the oak uplands, and the open uplands being 6.67 c.c., 7.6 c.c., 6 c.c., 7.93 c.c., 8.78 c.c., and 16.39 c.c. respectively. The high rate of evaporation in open uplands clearly shows the effect of shade in retarding evaporation. This gives some conception of the relatively high rate of transpiration of the plants that constitute the various crops as compared with the vegetation that springs up in the forests, it having been clearly shown by Livingston (10) that there is a definite relation between rate of evaporation of water from a free surface and the rate of transpiration in a leaf. 12 5. The graphs in Figure 27 (Pl. XV) show relatively high rates of evaporation when compared with the rates in other portions of the ravine. The average amounts of evaporation per day at the foot, middle, and head of the gully, or wash, were 8.93 c.c., 8.31 ¢.c., and - 9.32 c.c. respectively. The evaporation on the gully slope shows less. gradation than on the mesophytic slopes of the ravine, the differ- ence between the average at the foot and the head of the gully being only .39 c.c. The evaporation on the gully slope was about the same as that in the oak uplands, which was 8.78 c.c. per day for the season. There is no question that during certain parts of the day the evapo- ration was greater on the gully slope than in the oak uplands. These high rates of evaporation on this slope suggest a vegetation with a xerophytic aspect (see p. 5). In the early part of the summer the gully slope was nearer devoid of vegetation than during the latter part of the season. Reference has been made in an earlier part of this paper to the luxuriance of the late-summer flora of the slope (Pl. II, Fig. 3). These changes in the vegetative conditions would tend to account for the special variations in the graphs for the gully slope, the presence of abundant vegetation about the atmom- eter tending to check the evaporation and its absence tending to in- crease the evaporation relatively. 6. A comparison of all the graphs, with the exception of those for the station in the open uplands and the stations on the gully slope, shows a remarkable similarity in the variation of the average daily loss for the weekly intervals, the minimum evaporation occur- ring during the week preceding August 16 and the maximum during the week preceding September 12. The graphs for the station in the open uplands and the stations on the gully slope show that the lowest rate of evaporation was during the same week as for the other sta- tions, while the highest rate for the open uplands was during the week preceding August 2, and for the stations on the gully slope high rates occurred during the weeks preceding July 12 and 26, and August 2 and 31, as well as during the week preceding September 12. SUMMARY AND CONCLUSION The average daily evaporation rate for any weekly period was greater in the embryonic ravine than that for the corresponding weekly period in the narrow ravine; almost always greater in any portion of the broad ravine with mesophytic slopes than in the nar- row ravine; greater near the top of slopes of mesophytic portions of ravine than near the floor; generally greater at the middle of the southeast-facing slopes than at the middle of the opposite slope; al- 13 most uniformly greater near the top of the southeast- and south- facing slopes than near the top of the opposite northwest- and north- facing slopes; usually greater in the oak uplands than in any meso- phytic portion of the ravine; and, finally, the greatest average daily evaporation for any weekly period for any of the stations was in the open and exposed upland, as noted for the strawberry bed. (Pl. XVI, Fig. 28.) If the differences in the evaporative power of the air at the dif- ferent stations are taken as an index of the relative xerophytism and mesophytism of the vegetation, the preceding summary permits the following ranking of the stations, based upon their progressive xero- phytism: the embryonic ravine, the narrow ravine, the foot of the mesophytic slopes, near the top of the northwest- and north-facing slopes, near the top of the southeast- and south-facing slopes, the oak uplands, and, the most xerophytic of all, the open uplands, repre- sented by the strawberry bed. In general the movement is from a moderate rate of evaporation in the embryonic ravine to a lower rate in the narrow portion, and then a reversion to a higher rate, which gradually increases until it reaches its climax for the ravine near the top of the southeast- and south-facing slopes, and the climax for all of the stations in the open uplands. The average amount of evaporation for each of the stations, as shown in Figure 28 (Pl. XVI), strongly reinforces diagrammatic- ally the preceding conclusion. The data clearly show that the differences in the rates of evapora- tion at the various stations are sufficient to indicate that the atmos- pheric conditions are effective factors in causing plant succession in a ravine. MEASUREMENT oF Soi, Moisture Samples of soil were taken weekly at depths of 7.5 cm. and 15 cm. in the narrow ravine, station 2; at the foot of the most mesophytic slope of the broad ravine, station 3; and at the foot of the gully slope, station 13. Each sample was placed in an air-tight soil jar and weighed when brought to the laboratory, and then placed in a drying oven at a temperature of 100° C. for one week, or until it ceased to lose weight. It was then weighed to determine the loss in weight resulting from the removal of the soil moisture, and the amount of such moisture was calculated in terms of percentage of the dry weight of the soil. The results have been plotted with the weekly intervals as abscissee and the percentages of moisture as ordinates (Pl. XVI, Fig. 29, and Pl. XVII, Fig. 30 and 31). 14 It had long been thought that there could be no direct relation established between the percentage of water in a soil and the amount that is available for plant growth. Recently, however, a standard has been discovered by Briggs and Shantz (712) by which the water content of the soil may be directly related to continuity of plant vital- ity. They have termed this standard or constant the “wilting co- efficient” of the soil, and defined it (p. 6) as “The moisture content of the soil (expressed as a percentage of the dry weight) at the time when the leaves of the plant growing in that soil first undergo a per- manent reduction in their moisture content as the result of a de- ficiency in the soil-moisture supply.’’ Only the soil moisture over and above the wilting coefficient is available for plant growth, and hence this surplus has been termed “growth water.” In this investigation the wilting coefficients of the various soils were found by the “indi- rect method” devised by Briggs. and Shantz (’12: 56-57) which is based on the relationship of the wilting coefficient to the moisture equivalent as determined by physical methods. ‘These. coefficients have been represented (in figures 29, 30, and 31, plates XVI and XVII) by transverse broken lines, hence the growth water, or that portion of the soil moisture available for the growth of plants, is denoted by the interval between the lines representing the total per- centage of moisture present and those showing the amount of the wilting coefficients. INTERPRETATION AND DISCUSSION OF RESULTS 1. The graphs in Figures 29 (PI. XVI) and 30 (Pl. XVII) show that the percentage of moisture at stations 2 and 3 at a depth of 7.5 cm. was greater than at a depth of 25 cm. in each of the weekly examinations that was made. (The results are graphically represented, with the weekly intervals as abscissee, and the percent- ages of soil moisture at the time of each examination as ordinates. ) No such regularity in the per cent. of moisture content at the differ- ent depths was found at station 13 (Pl. XVII, Fig. 31). 2. The samples taken at a depth of 7.5 cm. show in a general way that the per cent. of moisture content in the narrow ravine at station 2 was less than in the broad ravine, station 3, and that the percentage of moisture content at the foot of the gully slope at sta- tion 13 was less than at either of the other two stations examined. The samples from a depth of 25 cm. did not show any such varia- tions. From this we must not hastily conclude that conditions were more favorable for plant growth from the standpoint of soil mois- ture in the broad ravine than in the narrow ravine, or more favorable 15 at either of these two stations than at the foot of the gully slope, but further examine our data. What is really important in soil-moisture comparisons is the relative amount of growth water, or the differ- ence between the actual water content of the soil and the water con- tent not available for growth in the plant. The average percent- ages of moisture at a depth of 7.5 cm. for broad ravine, narrow ra- vine, and gully slope were, in the order named, 28.3, 24.1, and 17.7. The respective .wilting coefficients for the same were 18, 15.1, and 10.2. This indicates that the average percentage of growth water in the broad ravine was 10.3, in the narrow ravine 9, and for the foot of the gully slope 7.5. Thus, from the standpoint of soil moisture, supplies were slightly more abundant in the broad than in the narrow ravine, and least abundant at the foot of the gully slope. If the wilting coefficient may be regarded as indicating a condi- tion in which the water supply of plants is reduced to such a degree as to catise permanent wilting, a recovery from which is only possible by an increase of the soil moisture, the graphs clearly show that at no time did the plants wilt permanently from the lack of water in the soil. One of the plants that wilted regularly during midday on sunshiny days was the jewel weed. This must not be attributed to the lack of water in the soil, but to a more rapid rate of evaporation from the portion of the plant above ground—a more rapid rate than that at which the water was taken in by the root of the plant. Such wilting would not be permanent wilting, which would eventually mean the death of the plant, but a temporary wilting, which would mean the restoration of the turgidity of the plant with a decrease of evaporation such as is caused by the coming of nightfall. 4. ‘These data show in general so generous a supply of soil mois- ture at the various stations within the ravine that it may be safely assumed that the soil moisture is a factor contributing to the rapid advance of succession in such situations, and should have consider- ation in explaining the early attainment of advanced mesophytism. 5. These data also show that while the variations in soil mois- ture are not great at the different stations, the differences that do exist correspond in a general way to those of evaporation and may indicate a contributing factor in causing plant succession in a ravine. In order to make these soil-moisture studies more convincing, weekly examinations should have been made at the other fourteen stations. CoNncLUSION The close relationship of evaporation and soil moisture to plant succession in a ravine is clearly evident from this study. It would have been more convincing if it had extended over a longer period; 16 but the writer does not believe that in case the period had been longer the general results would have been different, since the investigation extended over the most critical season of the year, namely, the part of the summer when the evaporation rates are relatively high and soil moisture relatively low; and these are the most critical conditions for the development and survival of plants. ACKNOWLEDGMEN’S — Grateful acknowledgment is here extended to Dr. H. C. Cowles, of the University of Chicago, for suggesting the problem and site for study; to Mr. and Mrs. McLeish for their kindness in permitting weekly visits to their estate, on which the ravine is located; to H. DeForest for photographs of vegetation in vicinity of stations, and to Dr. Geo. D. Fuller, also of the University of Chicago, for his helpful suggestions in overcoming the difficulties that arose in the course of the investigation. LITERATURE CITED Atwood, Wallace W., and Goldthwait, James W. ’o8. Physical geography of the Evanston-Waukegan region. Bull. 7, State Geol. Surv. IIL. Briggs, L. J., and Shantz, B. L. ‘12. The wilting coefficient for different plants and its indirect determination. Bull. No. 230, Bur. of Plant Industry, U. S. Dept. Agr. Brown, Wm. H. ‘to. Evaporation and plant habitats in Jamaica. Plant World, 13 : 268-272. Cowles, H. C. ‘or. Plant societies of Chicago and vicinity. Bull. No. 2, Geogr. Soc. Chicago. Fuller, Geo. D. 11. Evaporation and plant succession. Bot. Gaz., 52: 193-208. Livingston, B. E. ‘or. Operation of the porous-cup atmometer. Plant World, 18: ITI-119. 13. The resistance offered by leaves to transpirational water loss. Plant World, 16: 1-33. , PLATE I Fig. 1. Station 3, at the foot of the main ravine. Hard maple fallen across the channel as the result of lateral corrasion. Vig.2. Station 1, in an embryonic V-shaped ravine working its way back into the oak uplands. A miniature plateau showing a great variety and profusion Fig. 3. Station 14, in the gully. of asters. and slope covered with an almost purest cing on the middle of the south-fa Station 11, Fig. 4. of the hog peanut, Amphicarpa monoica. Piate III Fig. 5. Station 4. The lower half of the picture shows an almost pure growth of Osmorhiza /ongisty/is, on northwest-facing slope. PLATE LV Fig. 6. Station 5, near the top of the northwest-facing slope. Avalia nudicaulis is the domi- nant plant of the undergrowth. Fig. 7. Station 8, on the floor of the mesophytic portion of the ravine. \ PLATE V Fig.8. Station 6, near the middle of the southeast-facing slope. Hard maple and ashes are dominant. eo ee. ee oe re v ei " ’ - F . AT be hs . , 5 i 1 r we ‘ . Stree i PLATE VI Fig. 9. Station 7, near the top of the south-east facing slope. a) PiaTe VII Species characteristic of the slope. on the middle of the north-facing tation 9, vernal flora are abundant here. Fig.10. S c forest of the ravine. Station 10, in the characteristic mesophyti Fig. 11. Piate VIII Fig. 12. Station 12, near the top of the south-facing slope among red oaks and witch hazel. Fig. 13. Station 13, at the foot of the wash near the mouth of the ravine. The only place in the ravine showing Juniperus communis. PLATE IX Fig. 14. Station 15, at the head of the wash near the mouth of the ravine. Fig. 15, Station 17,on the open upland, The strawberry bed on the McLeish estate. tea be - i. Yi . cy 41 ost U i ‘ 1 ‘ e “ i PLATE X i] JULY AUGUST SEPTEMBER OCTOBER Base Riese HEC ene NEG \ \ Duar en @iaum PONCE N _ Fig. 16. Evaporation rates in an embryonic ravine (1), in a portion of ravine with lateral cutting delayed (2),and at the bottom of the most mesophytic portion of ravine (3). Stations 1, 2, and 3. AUGUST SEPTEMBER OCTOBER L_| |. : | | Fig. 17. Evaporation rates at the font (3), middle (4), and top (5) of the north- west-facing slope of the most mesophytic portion of the ravine. Stations 3,4, and 5. PLATE XI Al S Vil LU Na NS \ cr eae VU Fig. 18. Evaporation rates at bottom (3) and near the top of the northwest (5) and the southeast-facing (7) slopes of the ravine. Stations 3,5, and7 AUGUST SEPTEMBER OCTOBER Le a Ses See Pht a Seine sisi aust | : a a, cid Ic Dp 4 7 s=> ae Fig. 19. Evaporation rates at foot of the northwest facing slope (3), and middle (6) and top (7) of the southeast-facing slope of the most mesophytic portion of the ravine. Stations 3, 6, and7 Prate XII ff} uy |__Aucust—|__serrematr | ocroser al l Gl aerate co oe Bea | eC CEEaed eeoeoeel il css ian easel BEE a ose elias r MmISIo ee he ry eM) oie) Cy 22S o oa eee Aa EEE a 5 Fea Ban ian I rae al ets Sean (Pao I] oI i. aa L | . oI as alee SC 7 al PCC Fig. 20. Evaporation rates at the middle of both the northwest (4) and the Southeast (6) facing slopes of the most mesophytic portion of the ravine. Sta- tions 4 and 6. DS) Fe4 aiee a IN NY INN ON ie WNC PINNE bud ii Se | HH TSSSEhe een lia eee eee HLH Fee ee tal Fig. 21 Evaporation rates near the top of both nor hwest (5) and southeast (7) facing slopes of the ravine, the oak uplands (16), and the open uplands (17). Sta- tions 5, 7, 16 and 17. a) + ‘ie 7 " ‘ ‘ . ’ ~ PLATE XIII EBS AUGUST Gan 1 | OCTOBER ae 1 co 1 I | 1 B oe HCL Fes tate gna EET cot Co See Cooee cele ae COO ry eco IZIgal tale isan AN eine apt iA i mists WA COANE f\'N / 4 A) 7 jai dau Naan aur : VW WACO Seeecuccl SinieY (ais iabeiebeat fe etebel Fig. 22. Evaporation rates at the foot (8), middle (9), and near the top (10) of north-facing slope of ravine. Stations 8, 9, and 10. SEPTEMBER OCTOBER Fig. 23. Evaporation rates at the bottom (8) and near the top of the north (10) and of the south (12) facing slopes of the ravine. Stations 8, 10, and 12. ~ = —_ 54 1 ot ‘SI < 4 — o ira co (=) —< oO oO o ws co = lu e o we nan e na = Oo = = HIM LT | J “1 INN AY KAM Lt my y LT ZZAIN and near the top a han bs) oc 3 a rc Ea) n 5 i Fe! a fy n oc pee co of ra Oo o <4 ud a = = a ud n — na => oOo —) <= ~ 2 a oS oI ts g 3 5 o a vs e 7 eS oo ~ + ° ° & o) a Ks} Me «8 n o 2 NI I 8 ° bs FI u ° a 3 ia g Fig. 24. (12) of the south-facing slope. No Z 9 and 11. Fig. 25. Evaporation rates at the middle of both the north (9) and the south slopes of the ravine. Stations (11) facing PLATE XV SEPTEMBER OCTOBER rae i SSBB Se 7 JEBe an Fae Sa SS es MZ eat We, A AV Z) aN EEE A Fig. 26. Evaporation rates at the foot (8), near the top of the north (10) and of the south (12) facing slopes of the ravine, in the oak uplands (16), and in the open uplands (17). Stations 8, 10, 12, 16, and 17. | SaaS Boer as ee iene B z aero potal Fig. 27. Evaporation rates at the foot (13), middle (14), and top (15) of the wash or gully slope. Stations 13, 14, and 15. PLATE XVI Fig. 28. Diagram showing the comparative evaporation rates at the different stations on the basis of the maximum average amount per day between July 5 and October 18, 1913, AUGUST SEPTEMBER OCTOBER Fig 29. Graphs showing the range of soil moisture in the narrow ravine, Sta- tion 2, at depths of 7.5cm. (a) and 15cm. (b). Kroken lines show ths wilting coef- ficients for the soil at depths of 7.5cm.(c)andi15cm (d). PLATE XVII f, Fig. 30. Graphs showing the range of soil moisture at the bottom of the me- sophytic ravine, Station 3, at depths of 7.5 cm. (a) and 15 cm.(b). Broken lines show the wilting coefficients for the scil at depths of 7.5 cm. (c) and 15cm. (d). SESE FEEEEEEEEE WA Na Fig. 31. Graphs showing the range of soil moisture at the foot of the wash, Station 13, at depths of 7.5cm.(a)and15cm. (b). Broken lines show the wilting coefficients for the soil at depths of 7.5 cm. (c) and 15cm. (d). Pratz XVIII “ AVENUE ee Map of McLeish Ravine, Glencoe, Illinois. Scale about 7%, miles to the inch, : [Mie Pape BULLETIN OF THE ILLINOIS STATE LABORATORY OF NATURAL HISTORY Ursana, Inuinots, U. S. A. STEPHEN A. FORBES, PuH.D., LU.D., DIRECTOR Vou. XII. Marcu, 1916 ARTICLE II. A CLASSIFICATION OF THE LEPIDOPTERA BASED ON CHARACTERS OF THE PUPA BY Epna Mosukr, Pu.D. , » ; } H f i i ety ' ‘fF , . CONTENTS PAGE LANGTON, - ots onlto GEUBSEIEEne rr pas an ends dsb comnp ab ticop sca cenorpgEperen 17 Pete om NTE Ce MIM. PUPAL OM) 5 cic tre) sacl oio eilieinmisislole/eastercieslel dersieiaistessieraelsr sie. elon 18 RMR TAUTIEMIBTINO UI OLO LN ic 2.2, fcc, 2hs Ura etee AU devel arava atece a vorU,evere tare) etolelis ay olerayeraiatwistct sieie (che 22 CAUVISTMRODUTIOND (og RSC ORI NO SISO Rtacttcom bc Coc ONC OCCU r OO ToOceadons] Amsic Horan 30 AMMA cole, OF SUpPELLAMUIGS oe.cie ise cle viele eislejeme cis sicle cisve/eisiorcisia’> isrele rae 30 Pupae with functional mandibles......... tiidannorton ogesc doonaoconDondS 34 MITCNOP ULV OLUEM. larajere’y sets aicnareie se wietesreleretelerselave sietetereysre ete oiteieera) csi eisi« 35 TB RAGyOup te WCE ret anbeign Homie f oomone abc 200 Comnoborsartisioo maton fect toe: Eppa without functional mandibles) 4 -jyecteay< aei se ieisielete ole miersi\emaes) ieee eve 37 Generalized pupae without maxillary palpi ...........-..--.2e.eeeeeee ff GRAIG, ohonnqpaohencoup scone bonbpobodoadenonongodde boc padoS 37 RIG SPIEL ing ome pomear oO ODbie OU eS On OOO a AomonatiiaconsOEe 38 (CHEST Ch OSs Berens OraaHecinnismribtt chs toubo.clopidocmm cod adiner 38 SV ASTMAAL OMe ovat c.acais,'s © ac tie sstajel ore Sieusvetay taierae slate staretetet fers systehalaretsscha es 39 MOINS cdeomarares ars ata creceteis ath ciahaiees steers HomioInitte o ocacnckch ici pois CAE 40 TDN eer enios tooo OOD amp boc ubeacab aucesisobos cao e 41 INGTON) Oy ga ee ee oR PIn MO AOD MO OA TACOS cys Dot OD OEEOe 42 TDHOLEY OEY.) Rib es on Oi tiarie Goo Caco ce OG of oto BOOSH ROO ROO 43 eymOMON PEAS sis cscists sca ntmrar ts ocieies sia crate setae ma mberene eee emia a, © 44 Generalized pupae with maxillary palpi .............eeeeee cee eee eeu 44 AUER Mee Vets ens H caale atohereys lata s\ aie aiaelie fare eatal eel ote raey seme ene i sate ere 44 MTOM OVO AGL esate Fide, Greer stan nl yaya oral my aee shay anette sisal ole ttedatetsieye Matec ahe (elt 45 Noni WCE ener nore mida co Ouinu jolubocgue pecoubo nod ace yatic.cctci ome 46 BUEN Ey eee ORR Grace REE iPion tein tra woking CA On os Ch oye ven kOoe aoe 47 TENS IE a DAEs Fe eran Cone CIs IOI OIC GCC Ole GS OS ric mEOntanic De 47 PAM EMMOIGE Me ei wie) os env 5 die. dave sutuatiats wes a aearerasnc abst tty eich etenetta ate acts 48 PROD GINIDAG Ra al arse texc cde eCards Srntdlopeinte rel clenaiie © o)s\eiese ole 'ofoxelone fel steletatel=cs ara\c).e 49 Whit “coe See Geen Ee COGC Ot OnOtCm pierre Hces boo COO COEE OO ae 51 Ione Gh 6 hon BeIoD EOD asd SHON CEn OOD ODS Doda .ueaoados 52 Metheny aacrs: firs asi ietenm Papilionidae ..66. sce seen eee n cere nsnveetersecen snes senses It uG LCS GAA DD ADOC OOUCRODOUUCD OG CODDLDOSOCODDOE SO UOn Odum n~ DNiynmnpy alt de) 5! cteretelaelefa eleta)araie}ele)rcail-ietalelese)=/=/+)=(= im m= =|] l=\atainlata tale Specialized pupae without pilifers ............ Reopen ob iom ona so. pONOMeULOLEA 3). (elec c= wie o rine wie © i>imieleiwiaim ri=\=r2)a)m wfalsiel o/8ielisl>)staletels : Lal) er peCU AA enn aS OP Seo UES arOra DESC n acs eG CA es C WPOnOmeutidae . 2 scene cee nena cie enews > == a she in\ns)aelsle/s/=lr isle OMEN EGE) sepeanosnooasduoessubooMe ceseorouaddsdss beso ods. Gelechioided.22)oi2 sire» cre cre oetosclode ef) plates) pinis? osisvoFu joints ehaetsiehspetnteleeeteisieteies WWENGDINGEG) Gonondcoohonoecodopes df vfs ats a7) sor Aare) Sse eee eee Seythridid ae co ajcesyaterotaxe ays is's aa eter aes tcteeless ele ote felezaintae tee htanete Gelechiidae: sect. eerie sie relafe: e.c'2) ereyetes~ sfelalel ane) o/s%oin: siete o( vietnam renee ieee Chrrysopeleitdae’ «0:5 de0< cnet igs v2 2 weuvee ee eerie ee eee ee @ecophoridac’ . svt Sass Tank qastenes ae asiocse eee eee eee SLENOMIGAG a iajcpeieiee cies Siete aves suatete] eVatehe/aiecegs eve leetar Melee ete Soames COsmoptery P1dAe|. -pe\cccra:eretstaycy se: enatn) stoic Potare ste aera role emt fe fetfene ha sPanpeieetotets Wlachistidae. .occsjleccrave cael d suse s Genel oe ieee INO CHUOLA ES) ce adse sucks s, cue S60: 5) smaller ere oha es aael eh castles one a ene ame eats INO @ EULA! a5: aye ots) shares, soy azote Paper ate wiarlltesparalier clare tok far essere eaten esas PSM GENCY ERO BAC OOO OD OR AA AORD OO RMOn OS ono GGoSod lea eare ISM CPR COA AA A ooo oO ODOR MO POOH COO OrOOGcsono. cobee Coto bOS Bomb ye ud Gara sete rere atete oteloyal alot aleeiets etelel aval etehelet ic ctis iaisieisiefeieioisiacels/o sles ejeielecs:nieloleteielers/etefeteisteleisipie Saburmi1d ey aici oreisyaressrorera ore oterersloveratalverel sveteray afayleteie/etetate eteatets Angad Phylogeny! cxcisscve orn ain) viateleye satel saleeVer oreo olek elicit = ale relat avatny oLehaeatatepe lst ateteie da, chats Aeknowledgments: 21c:-/c:0j0 cic lepers c/sie(oleieis/o'ele;01s oisteleln/atutaveterevelsle/sleteleletatsieletefesere stele Bibliography. <.2/5, 6 EPIPASCHIINAE. Subfamily Gallerinae The pupae of this subfamily are very different from most pyralids and there is some doubt as to whether they should be included with 74 this family. The lobes which indicate the presence of pilifers are not well developed and the maxillae are short (Fig. 69). The body is short and thick and covered on the dorsum of the thorax and abdo- men with short spines. A strongly elevated median ridge is also present on the thorax and on the first eight abdominal segnients. The prothorax is very long, at least half the length of the mesothorax. The following species was examined: Galleria melonella Linnaeus. Subfamily Crambinae The pupae of the Crambinae are easily recognized by the peculiar form of the short, blunt cremaster and the deep lateral grooves on the tenth abdominal segment. Some of the species show a large portion of the labial palpi, indicating that this subfamily is one of the more generalized. The maxillae reach almost to the caudal margin of the wings and the tips of the mesothoracic legs meet on the meson just caudad of the maxillae. The segments are almost smooth, never punctate. The following species were examined : Crambus vulgivagellus Clemens, trisectus Walker, caliginosellus Clem- ens. Subfamily Pyralinae The species of this subfamily resemble closely the genera Plodia and Ephestia of the Phycitinae. There scarcely seems to be more than generic differences between them. The epicranial suture is present and the vertex always extends to the meson. The maxillary palpi are well developed and usually reach the proximo-lateral angles of the maxillae. There is never a cremaster present, but a transverse row of hooked setae at the caudal end of the body. The two genera studied may be separated as follows: a. Dorsum of abdomen with a furrow between the ninth and tenth seg- ments, the caudal margin of the furrow distinetly crenulate. Pyralis Linnaeus. aa. Dorsum of abdomen without a furrow between the ninth and tenth SCPMCIUS 1c 6 sce vie eee) ctoenei by eictehstons ei ee etorertere Hypsopygia Hiibner. The following species were examined: Pyralis farinalis Linnaeus f1ypsopygia costalis Fabricius 75 Subfamily Phycitinae This group is, for the most part, easily distinguished from other pyralids by the presence of the suture on the dorsum of the abdomen between the ninth and tenth segments, the presence of maxillary palpi, and, usually, of the epicranial suture. Of the genera examined, Ephestia and Plodia alone were without this dorsal furrow, and they possess tubular spiracles on the mesothorax. These two genera seem tather more closely related in many respects to the Pyralinae than to the Phycitinae. The maxillary palpi always extend to the proximo- lateral angles of the maxillae, and the epicranial suture is present in all genera examined but Pinipestis and Mineola, though it is very near to the suture between the head and prothorax. The vertex is usually represented by a small triangular area adjacent to each antenna. The lobes enclosing the pilifers meet on the meson in some genera. The genera of Phycitinae may be separated as follows: a. Dorsal surface without a prominent furrow separating the ninth and tenth abdominal segments; mesothoracie spiracles tubular. b. Abdominal segments punctate; maxillae reaching the caudal mar- (ald OFLA GEa anal iis Hib dipials Kio. par cg RAGOR Aen Ephestia Guenée. bb. Abdominal segments smooth; maxillae never reaching the caudal Marin, OL bee wANOse sap pee ieiers secs citys iei0is) =,« Plodia Guenée. aa. Dorsal surface with a prominent furrow separating the ninth and tenth abdominal segments; mesothoracic spiracles never tubular, their exact position usually difficult to determine. b. Body depressed ; tenth abdominal segment with the caudal end dis- tinetly margined and with six straight setae inserted on the ven- traeside or the mM areliem mse ae tees ee te. Acrobasis Zeller. bb. Body never depressed; tenth abdominal segment never with the caudal end distinctly margined or with setae inserted on the ventral side of the margin. e. Caudal end of body with four long hooked setae, and on each side of these a short spine or hooked seta extending laterad. d. Tenth abdominal segment with lateral spines very different from the caudal setae. e. Ninth abdominal segment with a lateral spine on each side similar to those on the tenth segment, and two hooked setae on the dorsum adjacent to the caudal mar- gin; caudal hooked setae equidistant... Wineola Hulst. ee. Ninth abdominal segment without lateral spines or hooked setae on the dorsum adjacent to the caudal margin, f. Caudal spines not adjacent; equidistant; of equal Len Oth EN emi te ete Mit les wicks cise Meroptera Grote. 76 ff. Caudal spines adjacent; two of them shorter than the Other Wr a alee ee ere Psorosina Dyar. dd. Tenth abdominal segment with lateral hooked setae similar to the caudal setae sc 6 <0 cc.ar0 brates elotelso Canarsia Hulst. ee. Caudal end of body with a transverse row of six long hooked setae of equal length; epicranial suture never present; head with a prominent pointed cephalic projection. Pinipestis Grote. The following species were examined: Plodia interpunctella Hubner Ephestia kuehniella Zeller Acrobasis rubrifasciella Packard Mineola indiginella Zeller Meroptera pravella Grote Psorosina hammondi Riley Canarsia ulnuarrosorella Clemens Pinipestis zimmermani Grote Subfamily Pyraustinae This group is distinguished by the peculiar “shouldered” appear- ance of the body, caused by the great width of the thorax as compared with the head and by the position of the labrum, which is always cephalad of its normal position and often located near the cephalic end of the body. There is never a furrow on the dorsum between the ninth and tenth abdominal segments. The maxillary palpi are always present and only a very small portion of the labial palpi is exposed. The epicranial suture is present in all genera. The mesothoracic legs and antennae, together with the metathoracic legs which are hidden by them, usually extend beyond the caudal margin of the wings. The mesothoracic spiracles often have peculiar ridges along their caudal margin which are sometimes covered with setae. Similar ridges are found in certain families of Papilionoidea and Notodontoidea. The shape of body and arrangement of parts in the Pyraustinae resembles that of certain Sphingidae, and would seem to indicate that the Pyraustinae are not as closely related to the Phycitinae as the other subfamilies, which all show a very close relationship. The genus Pyrausta as understood at present probably does not represent a natural group. Of the species studied P. fissalis and P. illibalis have long narrow cremasters of similar type, while P. futilalis and P. in- sequalis have short broad cremasters of rather different types. There is also great variation in the length of the appendages, but this is not such a decided generic character as the form of the cremaster. This 77 subfamily includes the largest pyralids examined. The genera of ’Pyraustinae may be separated by the following table: a. Setae of the cremaster always hooked and equal in length to the cre- master or sometimes longer; the other appendages never extending beyond the caudal margin of the wings. b. Setae of the thorax and abdomen very long, heavily chitinized, and forked at the distal end, usually much longer than the seg- ments; mesothorax and metathorax having a deep oblong pit with strongly chitinized edges at the base of each wing. ; Phlyctaenia Hubner. bb. Setae of the thorax and abdomen never prominent, scarcely ever visible; mesothorax and metathorax never having a deep oblong pit at the base of each wing. ce. Mesothoracie spiracle with a prominent elevation adjacent to the caudal margin, which bears several ridges fringed with setae; front with a distinet tubercle or small ridge at the base OL seach antennae jeer rsa ketene Ore cies or Desmia Westwood. ee. Mesothoracic spiracle without any prominent elevation ad- jacent to the caudal margin; front without a tubercle or ridge at the base of each antenna........... Pantagrapha Lederer. aa. Setae of the cremaster either straight and equal in length to the eremaster, or hooked and much shorter than the cremaster ; the other appendages often extending beyond the caudal margin of the wings. b. Prothorax with a distinct tubercle on each side of the meson; cre- mastral setae straight and spread out fan-like. Tholeria Hiibner. bb. Prothorax without a distinct tubercle on each side of the meson ; eremastral setae hooked, and not spread out fan-like. Pyrausta Schrank. The following species were examined : Phlyctaenwa ferrugalis Hubner Desmia funeralis Hubner Pantagrapha limata Grote and Robinson Tholeria reversalis Guenée Pyrausta fissalis Grote, illibalis Hubner, futilalis Lederer, insequalis Guenée Subfamily Epipaschiinae Only one species of this group has been examined, so no very definite statements can be made regarding it. The species examined seems to differ mainly in the absence of the maxillary palpi, which are present in all of the other subfamilies. The epicranial suture is not visible and the labrum is slightly cephalad of its normal position. The dorsum of the abdomen shows a decided furrow between the ninth 78 and tenth segments which is strongly curved caudad and apparently covered with some fine whitish setae, but this appearance may be due to the fine striations present. ‘The caudal margin of the furrow is crenu- late. ‘There is a very short cremaster present, bearing a small group of hooked setae, which are more than half as long as the tenth segment. The following species was examined: Lanthape platanella Clemens. SuprerramMity PAPILIONOIDEA The members of this superfamily are distinguished by the pos- session of lobes indicating the presence of well-developed pilifers and by their distinctly clubbed antennae. The genus Oeneis is an excep- tion, however, in not having the lobes well developed; but this is probably due to specialization, as it seems very closely allied to the Satyrinae, especially in the length of the prothoracic legs. Many of the Papilionoidea have prominent ridges and tubercles on the surface of the body, but there are also many genera in which the body surface is quite smooth and destitute of tubercles and ridges. The epicranial suture is present in three families, Megathymidae, Hesperiidae, and Lycaenidae. ‘There has been-a great deal of discussion and disagree- ment over the arrangement and subdivision of the families of the Papilionoidea. Some have divided it into two superfamilies, Hes- perioidea and Papilionoidea, but the pupae show no characters to war- rant such a division. The family Lycaenidae has been considered by many as the most specialized, or among the most specialized, of the families, yet it still retains the epicranial suture. In this family, how- ever, the labial palpi are entirely concealed except in the case of the aberrant genus Feniseca, and the shortening of the prothoracic legs is similar to the condition found in the Nymphalidae. It is impossible without further study of existing forms and a larger series of species to discuss fully the relationships between the different families. It is sufficient for the present to state that the Lycaenidae seem more nearly related to the generalized Hesperiidae, but have developed in a similar manner to the Nymphalidae, and that the Pieridae, Papilionidae, and Nymphalidae seem very closely related. ‘The families of Papilionoidea may be separated as follows: a. Proximo-lateral angles of the maxillae extending laterad to the eye- pieces. b. Maxillae never reaching the caudal margin of the wings; wings adjacent on the meson caudad of the maxillae. . MrGATHYMIDAE. 79 bb. Maxillae always extending to the caudal margin of the wings and sometimes beyond; wings never adjacent on the meson. HESPERIDAE. aa. Proximo-lateral angles of the maxillae never extending laterad to the eye-pleces. b. Mesothoracie legs never extending cephalad to the eye-pieces. ce. Epicranial suture always present; head without projections; exposed part of maxillae never as long as the wings. LYCAENIDAE. ec. Epicranial suture never present; head always with prominent projections ; exposed ial of maxillae usually as long as the wings. d. Head with two prominent projections, one at each cephalo- lateral angle; metathoracie wings visible in ventral view. PAPILIONIDAE. dd. Head with a median projection; metathoracie wings not Visible: im: verte WAEW, "1 r e@. 79. Cyaniris ladon, ventral view. @, 80. Oeneis semidea, ventral view. . 81. Euvanessa antiopa, lateral view, fifth abdominal segment. g, 82. Zelleria celastrusella, ventral view, male. . 83. Yponomeuta malinellus, ventral view. . 84. Plutella maculipennis, dorsal view. . 85. Argyresthia freyella, ventral view, female. . 86. Argyresthia freyella, dorsal view, female. e, 87. Coleophora malivorella, ventral view. ig. 88. Lophoptilus eloisella, ventral view, female. . 88a. Lophoptilus eloisella, lateral view, caudal end of abdomen. . 89. Seythris eboracensis, ventral view. [Ye @ so @ . ‘ > Sa > Seer —a is : ; — : PLATE XXVI Fig. 90. Gelechia serotinella, ventral view. Fig. 91. Trichtotaphe flavocostella, dorsal view. Fig. 92. Trichtotaphe flavocostella, ventral view. ig. 93. Evippe prunifoliella, ventral view. : ig. 93a. Evippe prunifoliella, lateral view caudal end of abdomen. ig. 94. Ypsolophus citrifoliella, ventral view. ig. 95. Chrysopeleia ostryacella, ventral view. ig. 96. Stenoma schlaegeri, ventral view. ig. 96a. Stenoma schlaegeri, dorsal and lateral views, fourth abdom- inal segment. Fig. 96b. Stenoma schlaegeri, tips of large lateral setae. Fig. 97. Psilocorsis quercicella, ventral view. Fig. 98. Psilocorsis quercicella, lateral view. Fig. 99. Cosmopteryx clandestinella, ventral view. Fig. 100. Elachista praelineata, ventral view. PLatE XXVI Fi Ey ) JQ IS 9 PI = = dq de 0d Ki el A ley} 4 lve} — sd 8 ie Q Fig. Fig. Fig. Fig aq ag ot . 101. . 102. ig. 103. 104. . 105. . 106. r. 107. 108. + AO): ig. 110. @. 111. g. 112. 113. 114. 115. . 116. PLATE X XVII Avrotis bicarnea, dorsal view. Cirphis unipuneta, ventral view. Eulonche oblinita, ventral view. Tsia isabella, lateral view. Hemerocampa leucostigma, ventral view. Malacosoma disstria, ventral view. Bombyx mori, ventral view. Brephos infans, ventral view. Hydria undulata, dorsal view, eremastral setae not present. Cymatophora ribearia, dorsal view, caudal abdominal segments and cremaster. Tephroclystis absinthiata, dorsal view, caudal abdominal seg- ments and eremaster. Melalopha inclusa, dorsal view, abdominal segments and ere- master. Datana angusii, dorsal view, caudal abdominal segments and cremaster. Schizura ipomoeae, dorsal view, caudal abdominal segments and cremaster. Phryganidia californica, ventral view. Phryganidia californica, dorsal view. BULLETIN OF THE ILLINOIS STATE LABORATORY OF NATURAL HISTORY Ursana, Iiurnors, U. S. A. STEPHEN A. FORBES, Pu. D., LL. D., DIRECTOR Wor. ll. Marcu, 1917 ARTICLE III. A PRELIMINARY CLASSIFICATION OF DIPTERA, EXCLUSIVE OF PUPIPARA, BASED UPON LARVAL AND PUPAL CHARACTERS, WITH KEYS TO IMAGINES IN CERTAIN FAMILIES. PART I. BY Joun R. Mattocu CONTENTS PAGE Tari o RROLIG US 2.2 hp OS ROIO GSTS G10.0.0 1.0 ) DOr ODO OBOROOE BOD. Cinna crac ckeee 161-173 PNCKMOWIED OMENES) <\ 5.05 ots te ioie areca orene eats tet ere bette ata ene 207-238 Kieys: tos Sn bLamiies 5/5: c ois atisra0' a /oa ota sie. 8 tein ad ee ttalecctapmtet erate calle wieiagee eka 212 (POGICIIMAE \2,nFeya15 ciaieya) arse ashe oie otolans Misi ee ic repe tere aise ST Are Oke ete arenas 216 Tarmmnophrlinae yx,o.cc oldie ls) oral tisfeiatere sterotoieiats: cates arptere ain ere 220 Rhamphidunae gael melariei ueleeialeiete eee are Sfopuicere 226 Biriopterinae: 2.5 2) c.cgeesctaatele avarcveleierecorstaievatareiniaaa eta eh ete aiars asad arate 227 aS tice: WR On OGD SIRO OUOGORD FORATCOM nist ROD SONOAD AsO %5 ‘ 232 AD rICHOCOTINAG a eyatateiedeetale ite iay ates elation oho ela e lato eTeg eee aetotieste ty aotace eels 234 Papers on the Biology of North American Limnobiidae..,.,.... 238 amily, Pity Chopterkdae ey cys:iei eis atetels Sita 238-241 Hamily: Rb ypHudaes, «cc)qjetesnicsesisicieae eloeie eivieteleleyetn en etsiareiatorersie ate a eae 241-245 Tribe Hucephalays scrstesaniess ste ction a ieee eee | Sotto ia teeta 245-291 Superfamily Mycetophiloidea wlsssl(ehssnyai avcvdtsue tole ctebeis excavate BISHE eo ees eee eee 246-262 ama yap OLTOp OU Ae steele ties tails iets eietelete eters icles eee 247-248 Raniily eMiycetopuwlidaes ayes. 1a cialis tiniest Sooo clerc gt a 248-258 Keys cho) Sub families secs ck piesa ciel aisle cilerate) «)stcoeretsdekerave)e totstale tesa 251 Mrycetophilim aay (2ies a teic e/etoja chevele\esetan irinis helelhejavalngayatelelagaluieietel =e? = ctelate 251 s(cl) Jie ibrte lpr n me AN oes NSN NOOSA OTAGO cad ae csc, : 255 Wamilys SClar dle sirereer telat tetelets eect ies paris Ae acc 258-260 Mamily, Macrocértdads. 6 ccis- ric. ccm ve serine tees eee see 260 Wamsly sP aby dae are ec airem eal citi eis ete eee eee ee 260-262 Principal papers on North American Mycetophiloidea............. 262 Superfamiliys Culrcoideas scyeraie state) ents cisiessete eavpioie eae atetel te keeeeeeae oneal 263-280 Pamily, Psychodidae. .i.si6.<)5 6 ore a siecetowe nino wle «0!» ols)e|aiemieTeleelermls y+. .264-274 Papers dealing with Biology of Psychodidae................... 273 Hamuly, PBlepharocerl dae sas ia)sccisterecln siclseletiaie sel ieee ee ar 274-276 Principal papers on North American Blepharoceridae Meg soscoo. 276 Litmimibys (Opibrotkres aesqoannsodadano ne aonecuactnosocsadasocune 276-279 Revs ston sib Lamiiliesis sya sleierichs omelets eieireeiee rete ate te ele rereeeeanen 278 Some of the more important works on North American Culicidae. . 279 Inpuiiby WysaCksh gacq aod nop oaon OCR Noon Cone ore monsABn ead Asoo 279-280 Paper containing account of North American Dixidae........... 280 Superfamily, (Chironomoidese cei crc or crear niece oie = fre eae rae 280-291 Family Ceratopogonidae. .. 0... ..+c- econ ners sew wicqeteyoyse SaeYS '. 281-284 PheamMlhy (OlnmyNOnMGes sao aad qoobeceododnonadsoedjesecdantonnun cs 284-290 Keys to subfamilies................. iivaitVs peiw/a te eMevelata aie Syanabetare tet 286 MPearLy INA = pie lets wleletet oleh eleelat (eral ate|etat-fevalelat=fetel ated la eleey= T= (telalar fear 287 Chironominae «.) eyrstsisstaeieiiereie cron oor esis eae eee 287 Important papers on North Arnerican Chironomoidea............ 290 HMamaily Oxphrnepwwxd se sere eleote ole ccele ove le ele ate ce) oretet= tees si= iota el ee te ate 290-291 Tribe OM PONEUTas:./ajeneloiele avers’ =)siaVahs (a erehevee isle) erates etary Cel=tasel else cloxc tte ete 291-305 Superfamily (Cecidomyioideas rs). r ee ctees ete) e a ere = tein rials ieteials'=)er-faneie te 292-297 amily Cecid omy Gaels ereyere aieiele llores tesa sacle te eesti eee 293-297 Important papers on North American Cecidomyiidae............ 297 Superfamily, BiVLOMOVACA) cyeyere al erete wrote ele 3/6) etret el w= ete e tetera == arene es 297-305 lopheiha Whee ean qooncocdnenoododuc UbobrObos oso pecdonsc ue 298-300 Important papers on biology of North American species......... 300 amily sScatopsrd ser ecie cee. o/<'ace\s: efulatorejeiemnce ei clele) sale’ «2s s) nie ayn stayare me 8 ce yees oe 307—407 Hupnlarcarranpement Of Lamiliesseicieistere core 2 < alee cc's ois wn ceieiseencieece 308 Keys to families :— ILGINGE: got sovseqapseBeburiok y hani0on oo OOo DOO OO SD TOU BA SOOeUoner 308 IEMs 06 o CORO ROORU RE ODEOS OD NO LOD ERAS CONDE DonOCEOaD TCO r one 310 Horn sa IMCS ge mecn vet oat A's: s1c;0-cy spo aReR MME cea eke lc aks A sagitln:« o\aseiale. cisyaje's. aes 312 PEST POMEL AGO OTN A <5, «2, «] osoara) acer epegeleraial aTeve(eVsre Gia, 82 © Sa elchaYs sleicie, wm aveysie'e.6 3 314-399 HBL aMUlye StrAtlOMYIOIGGA a ctor ve!ayecpsic/eveta!e aia) -1< a\a\2\e.0, ee + ore eie:41s\016 a: 314-354 DERIK; isting ait De asinnna.c op esTdlon eae SO GOTO SOR OOMOmEenooe 315-346 Gye COMA LATION f a:0) ePalsttreierelotareranslnicleiste vic) sle.c. olsievece)= eiejels)<(ate sie'ale 316 MitaAONyAUNAD \ Ais cyersrereeet ie cteteiocise moves ets evenyeetcs ab Se ietecas 317 (CLEIGH DIET aia Scan ss ncon yop eee ode le noo CoCDOOOCGO BUM bOaE 322 IES eG thie ae eTOIO TOC Dien 0: ANCE AIDIES HACC CISC FE OTe Ero 331 (GEGRAL ONDE te ase ie cheese tietetaieiniery site eis cate empre rntctae uN eae ais ce 331 AGU OASLONIMAG Pavan ceteris telstpierela’sisis siaiel ates sicha¥a sieve sve isis acta =i 334 Mey LOM V RNAS el sciertinie Stee traie is) eile in ole leysyy oesiciniays icles = ntoe « Sade Slaetde See ae se BS Bra RS. See ARE ORNS ORTHORRHAPHA-BRACHYCERA. — Mazxillae poorly developed, their palpi visible only in a few groups; mandibles short and hook-like, usually capable of protrusion much beyond apices of maxillae if these are present; antennae poorly developed or absent, when present situated upon a membranous’ ISUATENOG), llacd.3 cathe RCI RER ORCA Cae eICRO Cece CYCLORRHAPHA. PUPAE 1. Pupa not enclosed within the indurated last larval skin, or if so the head is distinct as in the larva, or the puparium is slightly flat- tened dorso-ventrally, its texture leathery, not chitinous, and the anterior respiratory organs not distinguishable; imago, or pupa, emerges through a rectangular split on dorsum of larval skin... 30 6 BLS SUOMI CORO PSII SERCO RTE ORTHORRHAPHA — Pupa enclosed within the indurated last larval skin; head always retracted, the chitinous portion occupying a position on the inner side of the ventral surface of the puparium; anterior respiratory organs distinct, either protruded from the antero-lateral angles of the cephalic extremity or from dorsum of base of abdomen; imago usually emerges by forcing off the rounded anterior ex- tremity of the puparium in cap-like form, or the dorsal half of the thoracic portion—the lines of cleavage being along the lateral margins to a point at base of abdomen; rarely emergence is through rectangular splitting of the dorsum of the puparium... 56 Ot CALA PRT toni SOOO e AEE Cree CYCLORRHAPHA. 180 IMAGINES 1. Antenna consists of a 2-jointed seape—the basal joint usually indis- tinect—and a distinctly segmented flagellum of more than 2 joints adie ele DUA SAR Ee Sree ORTHORRHAPHA, pt. — Antenna consists of apparently 2 or 3 joints and, usually, a ter- minalor dorsal: Avista’, cis cpneveresesise tae reer teea ce icele en e 2 25) Mrontalaluniule absentia eisai ieee ORTHORRHAPHA, pt. -— Frontal lunule present, or if poorly developed or apparently absent there are no distinct cross-veins on dise of wing..............-- a yep area ate eters lafonckar ere neheas take Laie yekee te ote eee CYCLORRHAPHA., Suborder ORTHORRHAPHA Keys to DIvIsIoNns LARVAE 1. Head complete, or sometimes incomplete posteriorly ; mandibles ab- - sent or vestigial in Cecidomyiidae, but the body consisting of 13 segments in addition to the head, in other families mandibles present, moving horizontally or nearly so, their position when at rest being on a horizontal plane, or varying but slightly from. it, their apices opposed; labium usually well developed, in the form of a flat plate with or without dentate anterior margin; larvae frequently peripneustic, the aquatic forms usually with protrusive anal ib oodecillistecisr eerie ae iets NEMATOCERA (p. 182). — Head always incomplete and partly retracted within the prothorax; mandibles moving vertically, their position when at rest vertical, the apices parallel and directed downward; labium poorly de- veloped, rarely or never in the form of a flat plate; larvae nor- mally amphipneustic or metapneustic, very rarely peripneustic, aquatie forms without protrusive anal blood-gills.............. Ge SIA PEP Ye nO SE ae Re BRACHYCERA (p. 307). PUPAE 1. Head, except in some Cecidomyiidae and a few Tipulidae, without strong thorns; antennae much elongated, always very distinctly traceable, normally curved well over upper margin of eyes and extending to or beyond base of wing, in some cases almost to apex of wing; thoracic respiratory organs much elongated or sessile; legs of variable length, often extending to apex of abdomen, rarely slightly longer than wings, in aquatic forms often recurved against base of abdomen; abdomen in species with short antennae some- Mbiesh ioe aillonsownonaahc deus dooce NEMATOCERA (p. 182). — Free except in Stratiomyiidae; head in other families usually with 181 strong thorns, or if these are absent the antennae are very short and project downward and outward and do not curve over the upper margin of the eye or reach nearly to base of wing; thoracic respiratory organs sessile, rarely stalk-like; legs of variable length; abdomen usually armed with strong spines or bristles, or if unarmed there are only 4 or 5 distinct pairs of abdominal spira- CLONES is. oo 5,0 2 sO eta i2h ws BRACHYCERA (p. 307). IMAGINES 1. Antenna consisting of at least 7 joints, frequently filiform, rarely conspicuously thickened, but if so the joints are distinct and the flagellum does not appear as a single joint with poorly defined subdivisions, and the palpi are pendulous, consisting of 4 or 5 joints; antennae with or without whorls of hair on the joints, never with a terminal arista or style; palpi always pendulous, normally consisting of 4 or 5 joints, very rarely of only 2...... 5 aac ie: Obs Ch-a8 8 CC eee NEMATOCERA (p. 182). — Antennae consisting of 3 joints, the third occasionally having more or less distinctly annulated subdivisions, but in such eases the palpi are porrect and consist of 1 or 2 joints; antennae with short pubescence or with thick branches, in some families with either a terminal or subterminal style or arista; palpi projecting forward, consisting of 1 or 2 joints............ BRACHYCERA (p. 307). 182 Division NEMATOCERA TABULAR ARRANGEMENT OF FAMILIES My present grouping of the Nematocera is as follows. Tribes* Superfamilies Polyneura { Tipuloidea Mycetophiloidea Eucephala Culicoidea Chironomoidea Cecidomyioidea Oligoneura [ Bibionoidea The sequence of the families in the keys is not in accordance with the above list, the keys being framed to facilitate identification and not to indicate affinities. *Tribe in this paper does not have the application given to it in contemporary papers, but has that which Brauer gave it. He used it to designate his subdivisions of the larger divisions of Nematocera, ete. : Families Tipulidae Limnobiidae Ptychopteridae Rhyphidae Bolitophilidae Mycetophilidae Sciaridae Macroceridae Platyuridae Psychodidae Blepharoceridae Culicidae Dixidae Ceratopogonidae Chironomidae Orphnephilidae Cecidomyiidae Bibionidae Scatopsidae Simuliidae Sd > = 183 Keys To FAMILIES LARVAE Head incomplete; thorax and abdomen combined consisting of 13 segments; larvae peripneustic; usually with a chitinized plate (very distinct in mature larvae) on ventral surface of second thoraci¢, Seoment « «:«.<.... s/c os ees voces CEcIDOMYnDAE (p. 293). Without the above combination of characters.................. 2 Head and thoracic and first and second abdominal segments fused ; larvae with minute abdominal spiracles; abdomen with a ventral longitudinal series of sucker-like dises...............00.00005 SiC. CRON PED CHSC COED ED ERO N CHEIENG er SC RERCROE BLEPHAROCERIDAE (p. 274). Head free, or if retracted within or fused with prothoracic segment the other thoracic segments are distinct..............-.....-- 3 Head complete, enclosing first ganglion; mandibles opposed...... 5 Head incomplete posteriorly, either with 3 deep wedge-shaped slits, 2 on dorsum and 1 on venter, or the ventral surface very poorly chitinized and the dorsal one posteriorly in the form of 4 slender heavily chitinized rods, with a weakly chitinized divided plate on anterior half of the) Gorsttms « «i033 jeej0 00 ask jstioe es eees ves os 4 Apical abdominal segment with 6 radiating protuberances, which are rarely poorly developed but frequently unequally so; body segments with regularly placed bristles, as shown in Figure 1, Plate XXVIII; head heavily chitinized, dorsally slightly arcuate and with 2 longitudinal slits, ventrally slightly rounded and with a central slit; antennae Jonger than maxillary palpi; labium pointed, not divided into 2 plates, the anterior margin dentate; mandibles very stout, with only 2 teeth (at apex) in species with- out apical processes...........c cece e eee TIPULIDAE (p. 191). Apical abdominal segment with at most 5 radiating teeth, or if 6 are present the labium is subdivided centrally ; body usually with- out regularly placed bristles, frequently with dense surface pilosity ; head sometimes weakly chitinized and without distinct labium ; antennae sometimes short and slender and not as long as maxillary lobe (not palpus) ; labium frequently subdivided into 2 plates; mandibles never with only 2 teeth. LrIMNoBmDAE (p. 207). Thoracic segments fused and dilated, forming a complex mass.... BPRS Ney AASE SPY esa Gae. « IRENA SEES ser oganalalsnn ts 5 CuULICIDAE (p. 276). Thoracic segments not fused, distinct................eee eee euee 6 Larvae peripneustic, or with at least rudimentary abdominal RIL ACL ON treetops TEL of NOE PIER NOI cis) cP e osteo | ok Sova) ore conichovrauahe cele olal Ul Larvae amphipneustic or metapneustic..................000 ee 12 Larvae with rudimentary abdominal spiracles; mouth with a large articulated process on each side which bears a number of long* hairs and closes, fan-like, when at rest; posterior abdominal seg- ments dilated, the last one armed on venter with a sucker-like dise which bears concentric series of bristles, by means of which the 10. Tn 12. 13. 184 larvae retain their hold upon rocks, ete., in the streams where they ‘are found 2 jieeenioe cc eee ane SIMuULUDAE (p. 302), Larvae with distinct though sometimes small abdominal spiracles; mouth without fan-like processes; posterior abdominal segments not noticeably dilated, the last without sucker-like dise ; terrestrial species! fo 0.6 dss OR te, Ae ites oaths Gene 8 Antennae elongate; body armed with conspicuous bristles or hairs Antennae usually short and inconspicuous, sometimes apparently absent; body without conspicuous bristles.................4. 10% Anal spiracles at the apices of a pair of long stalk-like processes... . Sade alse ha sele Me aw oooh erd enaiere ga ai aune mises ScaToOpPsipaE (p. 300). Anal spiracles not noticeably elevated, situated near base of dorsal surface of apical segment................. BIBIONIDAE (p. 298). Dorsal, or eclypeal, sclerite of head not conspicuously tapered pos- teriorly ; antennae well developed...... BoLitoPHILIDAE (p. 247). Dorsal, or elypeal, sclerite of head conspicuously tapered pos- teriorly; antennae almost indistinguishable................. 11 Lateral sclerites of head meeting on ventral line only for a short space immediately caudad of mouth-opening, not connected at PoOsteriommMarcines masts eel ee MYCETOPHILIDAE (p. 248). Lateral sclerites of head connected for a very short space behind | mouth-opening and again near posterior margin........... , ahaa a haldlias SAREE abe ee an SaO RETIRE strlen is cera fetie ee the nem SCIARIDAE (p. 258) Dorsal surface of first and second abdominal segments each with 2 wart-like elevations somewhat resembling pseudopods, the apices of which are armed with numerous small hook-like setae; larvae AQUALICVaMphipmeusticn. sess ee oe teehee seks DrIxmak (p. 279). Dorsal surface of first and second abdominal segments without ele- vated’ processes’ s..). Ss oSSis Beli ane sine ate Seepage eee ene eine 13 All or some of the dorsal segments with narrow, chitinized, strap- like transverse bands, or the apical segment in the form of a short chitinized tube; rarely the ventral abdominal segments bear a central series of sucker-like dises....... PSYCHODIDAE (p. 264). Dorsum without narrow, chitinized, strap-like bands, apical segment not in the form of a short chitinized tube; ventral abdominal seg- ments never with sucker-like discs..............-2-2+eeeeees 14 Apical abdominal segment with long, slender respiratory tube.... GOED CIO To BerSic. oko Bae alba cic PTYCHOPTERIDAE (p. 238). Apical abdominal segment without long respiratory tube........ 15 Antennae undeveloped, appearing as pale round spots on sides of head; ventral surface of head with the sclerites contiguous ante- riorly, widely separated posteriorly....-..................++. 16 Antennae pedunculate, usually well developed; ventral surface of head with sclerite contiguous on entire length, not separated widely “posteriorly es 5 sick ee ecte lye asics eter eee erst eters 17 16. 19. 185 Head subquadrate; abdominal segments with a number of rounded EPANSVELSCITIG GES. . sons candle aidietss wee bole os PLATYURIDAE (p. 260). Head elongate; abdominal segments without transverse ridges..... PSP T ATCC A Merete! arate fy & a/c aval ateme elaye es lope MYCETOPHILIDAE (p. 248). Abdominal segments not subdivided..................-.-.-0-. 18 Abdominal segments subdivided by means of transverse constric- ROD SM MMC Erste) os sis SR ere nie clasr oe leatacs Mert ccred be ee 19 Larva very slender, tapering towards the extremities, without thoracic or anal pseudopods or surface hairs except about 8 at apex of abdomen, aquatic in habit; or stout, with well-defined segments which are armed with strong bristles, some of which are lanceolate; pseudopods present; terrestrial, living in manure or Mnaer Darks che: tae asereirece tits. 2.5.2 CERATOPOGONIDAE (p. 281). Larva rarely very slender, generally of an almost uniform thickness, rarely with the thoracic segments appreciably swollen but not fused; abdominal and thoracic segments frequently with rather noticeable soft hairs, the last segment almost invariably with a conspicuous tuft of hairs on dorsum near apex; pseudopods al- most always present, sometimes only the thoracic one distinguish- able in terrestrial forms—which are very rare..............-.-+ Pe cay. Gabe sieh siistarloacon Suotele ciand etava eee id mia wes CHIRONOMIDAE (p. 284). Body slender, tapering; abdominal segments each with a single con- striction near anterior margin; apical segment either with 5 short terminal processes or without distinet processes............... BPP eet ee betes scab isl vies hos), oslo sue, envisage ae &: Se vlaue RHYPHIDAE (p. 241). Body stout, of uniform diameter; abdominal segments each with 2 distinct constrictions ; apical segment with 4 rather long processes, the lower pair longer than the upper. .LrmMNopmpagr, pt. (p. 207). PUPAE Head with several strong thorns in a vertical series on the median line; pupae enclosed within galls on various parts of plants.... 2. Gait 6 EDO Ct CD EET ACR RICC RIeeoEE CECcIDOMYIIDAE, pt. (p. 293). Head without strong thorns, or if at base of each antenna there is a protuberance it is not sharp and thorn-like, and the pupae are not enclosed in galls on living plants.....................05. 2 Pupa enclosed within a tough, parchment-like envelope consisting of the hardened larval skin, which resembles a muscid puparium. . 2 Oe Se oie co On oae nde en eer CECIDOMYIIDAE, pt. (p. 293). Pupa free, or if enclosed it is within a cocoon which is not parch- ment-like and does not resemble a muscid puparium........... 3 Thoracic respiratory organs sessile; abdomen without strong thorns or leaf-like elevations; legs straight...................0000e 4 Thoracic respiratory organs stalk-like, or if sessile the abdomen has strong thorns or leaf-like elevations, or the legs are recurved against base of abdomen and apex of thorax, or the coxae do not =-I co 10. 186 conceal the sternopleura and the scape of the antennae is almost globose: legs) straight ‘or recurved. - ie tice eee erent 8- Legs short, apices of hind tarsi projecting slightly beyond apices of wings; antennae short, curved across middle of eye............ RC CO rir CaO aoa. S aod. BrBIoNIDAE (p. 298). Legs elongate, usually all tarsi projecting for a considerable dis- tance beyond apices of wings; antennae elongate, extending to or beyond ‘bases! of wings 054... See aceite te chiel-|. Oe eens 5 Antennae almost straight, noticeably flattened, extending to bases of wings; thorax not much swollen in front, its anterior pro- — Hle-notVaeclivatouss ee otek cite cece ee PLATYURIDAE (p. 260). Antennae distinetly curved, not flattened, extending beyond bases OE. WAMES! WRIA: Bota roe ore ta ia lair labesta ohh eet ete eee 70 Thorax conspicuously swollen, almost globose, its anterior profile de- clivitous; sternopleura conecealed...... MyceEtoPHILipar (p. 248). Thorax not conspicuously swollen, the anterior profile not deelivi- tous sos oe ce eeP Ae Rc ie le ite tee ee 7 Scape of antennae much swollen, globose; abdominal spiracles small or absent; sternopleura remarkably enlarged, not concealed by fore coxae and femora..... Thacher aca Ade CHIRONOMIDAE (p. 284). Seape of antennae not much swollen; abdominal spiracles distinct; sternopleura not visible, concealed by the large coxae and femora of the fore legsssra. seers. reli Crcipomympar, pt. (p. 293). ScraRIDAR, pt......(p. 258). Thoracic respiratory organs’ slender, long, and tube-like; legs straight, extending well beyond apices of wings; body without armature except a pair of hairs on anterior margin of head; sternopleura concealed............ ‘CECIDOMYIIDAE, pt. (p. 293). Scraripak, pt...... (p. 258). Species without the above combination of characters, abdomen usually with hairs or spines, or the sternopleura is exposed..... . Pupa in a pocket- or slipper-shaped cocoon consisting of coarse threads, from the wide, open extremity of which project the thoracic respiratory organs, each of the latter consisting of 4 to 60 tube-like branches on a common base; rarely the cocoon is a mass of rather loose threads............... SIMULUDAE (p. 302). Pupa free, or if enclosed or partly so the cocoon is not pocket-like and the respiratory organs do not consist of tube-like branches. 10 Pupa when seen from above oval in outline, the abdomen at base not conspicuously narrower than thorax, so that the lateral outline is continuous; dorsal surface with very strong, almost chitinized, MOMbLANes ei wsass ae esos eoay ers, ons Otapeveneros, cies sauces eon enone et eRe 11 Pupa with the abdomen well differentiated from thorax, the dorsum membranous, or if strong and almost chitinized, then with surface spines...... Sete Bie ake gral co are oN te ats ake fereretebenters sie eeeewee cee 11. 12. 13. 187 Thoracic respiratory organs lamelliform, consisting of 4 flat plates, the broad sides of which are contiguous.............0.0ee00: 4 SOUS COS 0 COED Co COD ODO rc BLEPHAROCERIDAE (p. 274). Thoracic respiratory organs simple, tube-like..................-- choi oRb ee eon Re lo eee PsycHopipar, pt. (p. 264). Apical abdominal segment terminating in, 2 or 4 paddle- or fin- shaped organs which are fringed on all or a part of their outer surfaces with strap-like hairs; or if the apical segment terminates in 2 long subconical processes the tarsi are, as in the other group, recurved against the ventral surface of the base of abdomen and apex of thorax so that they do not extend beyond the apices of THEI SE ees GROG Cecil) Sic 5 310 © GG ROTOR REI RE OTTO ROT CRE RE ae 13 Apical abdominal segment obtuse, armed with short or elongate spines or thorns, or if ending in a pair of long, slender processes these are more or less oval or circular in transverse section and without strap-like hairs; tarsi generally entirely straight, rarely the apices of the hind pair incurved slightly, but they are never MECUEVCG HASKADOVE sys aicuae ate valch sists are, oie, acchetorsvoia Sie te-alssarsishaneforey ove 18 Thoracic respiratory organs terminating in numerous thread-like HDI poke pole tao CO ODOT CHIRONOMIDAE, pt. (p. 284). Thoracic respiratory organs consisting of a single stem, in some cases with a few long, or many short, scale-like surface hairs, but never terminating in numerous thread-like filaments; or occa- sionally the thoracic respiratory organs are not elevated....... 14 Thoracic respiratory organs not elevated, sternopleura exposed. . 5 OS beet SEG CoE Or end eer TEER CHIRONOMIDAE, pt. (p. 284). Thoracic respiratory organs conspicuously elevated............. Thoracie respiratory organs situated close to anterior margin 2 thorax; thorax and abdomen without stellate hairs............. SOR COU Tod CHORD Ee Cee CHIRONOMIDAE, pt. (p. 284). Thoracic respiratory organs situated close to middle of thoracic dor- ULEAD toes atts etahfoh sel wicafete Gai s ah coe ie ea! «, 9} aya favade faze-iciaielaiese'e 6) ope te-eteelinynieie's 1 . Apical abdominal segment ending in 2 or 4 broad, flat, paddle-like LAOS. tstotonetticcs, otAocte psteros aw’ sidered CUuLICIDAE, pt. (p. 276). Apical abdominal segment ending in 2 long subeonical processes. .17 Apical processes armed at apices and on middle of their outer mar- gin with short hairs (3:1)............. CuLICIDAE, pt. (p. 276). Apical processes umarmed...........c2eeeeeees DrIxIDAE (p. ih Apices of legs not extending beyond apices of wings............ Apices of posterior legs at least extending beyond apices of wee Dd EwOAD ODAC COR OD EIOBE DD Gti! JADA nee One Decora 2 Apical abdominal segment ending in 2 conical processes........... = ON AAR aa SCE CERATOPOGONIDAE (p. 281). Apical abdominal segment ending in 2 upper and 2 lower short MUON erareh aca a eens Teen ome PsycnHopipar, pt. (p. 264). 22. 23. ene ot 188 Thoracic respiratory organs long, bifid; apical abdominal segment rounded, without processes; abdominal spiracles pedunculate.... ~ Jie. Sle dcegel Sve ete le eregetthate ea ep aieiee settee ene ScaTopsipAE (p. 300). Thoracie respiratory organs simple; apical abdominal segment not rounded, generally armed with protuberances............... 21 Thoracic respiratory organs elevated but little above the level of dise of thorax ; tarsi of the fore legs overlapping those of mid pair, the latter overlapping those of hind pair, all rather closely fused tovet ber ands to: witteseerstamelen serrate eee RHYPHIDAE (p. 241). Thoracic respiratory organs very conspicuously elevated ; legs not as Neo) ee Aa cia A ier irer mii cednata bs G dGktese o.0,0 ¢ 22 Thoracie respiratory organs equal in length, rarely with one twice as long as the other; anterior, middle, and posterior tarsi distinct Thoracic respiratory organs of conspicuously unequal length, one many times as long as the other; anterior tarsi overlapping mid- Gle Maire ee eaten seas tot eters ..PTYCHOPTERIDAE (p. 238). Abdominal segments each with 1 transverse row, sometimes 2 such rows, of thorn-like protuberances; palpi recurved at apices...... Se An AL GA aaa So Act Oe TIPULIDAE (p. 191). Abdominal segments rarely with distinct thorn-like protuberances, ~ usually with weak hairs; palpi straight, not recurved at apices. . 1 Sia f Bie NRO agern, Stes asenattoncparaverctal ered shanaueh arena sets LIMNOBUDAE (p. 207). IMAGINES Wing with at least 9 veins extending to the margin (exclusive of the anal vein) ; if there are only 8 such veins the radius is 3-branched, the second branch having its base proximad of the radio-medial CYOSS=VOMT hee ei ct Ss Ee aR en, be eee prec Reena 2 Wing with less than 9 veins extending to the margin, or the vena- EON MOT AS TADOVES s view orcaete oletars ete Retetirs ele hey ene coon che tomeveetedere 8 Mesonotum with a more or less distinct V-shaped suture; male hypopygium generally very large, chitinous; female ovipositor conical, chitinized, and generally pr otruded:<.i.< GEN 3 Mesonotum without distinct suture, or if there is a poorly defined suture it 1s not, V-shaped sinc cms ei eiciclsicrtetaie cenene neler eketenaretee 5 Wing withs2 sanals veins’ 2.70 c.0:ei satol-toceysioteetay Poteet ster Cn rerattene eel 4 Wine with) di amall vein. cir «si ' Ges ostth OFS coc RHAMPHIDIINAE (p. 226). 209 Segments at least as long as broad, lateral margins without strong ININS 6.6 5 6.06 DIG E ORG 01.4 Cit bio CarcaceS EN ICRI a nes ea 8 Body covered with short decumbent hairs, or, if bare, without nar- row stripe-like locomotor areas; apical segment with 4 or 5 IDDOCOSSESiicrascsicrs oss @ «meme leo velee & LIMNOPHILINAE (p. 220). Body without decumbent hairs; locomotor organs consisting of nar- row transverse strips on dorsum and venter which are slightly leathery and armed with short spinules.....................: SSRIS GB RCD LORE Saab ae Ane LIMNOBIINAE, pt. (p. 212). PUPAE Thoracic respiratory organs very short and stout, not more than twice as long as their greatest breadth; armature of abdominal segments weak, the same on dorsum and venter, consisting of a single narrow, chitinized or setigerous, band................- 2 Thoracic respiratory organs very much elongated, usually more than 6 times as long as their greatest breadth or they are knobbed at apices; or abdominal armature usually strong, thorn-like or Spimose sor nofanMitne, torm) Of PANGS... ei. occ cca ne tenner e ss 3 Thoracic respiratory organs well separated basally............... BE do Nrcyict spn otocac tons chateteusyo lira ay a tys bac ast Siala-aiis LIMNOBIINAE, (p. 212). Thoracic respiratory organs subcontiguous basally............... eRe e Use cfs VCs 1eveneEa ds acne st ave sver ater aieucniieke ve%).¢ RHAMPHIDIINAE (p. 226). A pair of large leaf-like projections above bases of antennae....... 3D OOL.D Clon calcein Gekciicc Dist icmine oto HEXATOMINAE (p. 232). No leaf-like projections above bases of antennae................ 4 Abdominal segments each with 2 or more very long thorn-like pro- jections on posterior margin, which are in some species armed with small branches; rarely these projections are confined to apical 2 segments.............0000: CYLINDROTOMINAE (p. 210). Abdominal segments each with small spines, or if rather large pro- jections are present they are short and leaf-like, rather numerous, PME CUMMLIEUD LAIN CL CG nasreteste stays fo) cet los ae lat. che alc! a dials el» le olsl'dsdate,oselelsioss 5 Thoracic respiratory organs stout, knobbed at apices.............. ok apatatanch Seed elle, a1 atars aysteksokd sha Weud ah elacaer ereye, ales PEDICHNAE (p. 216). Thoracie respiratory organs slender, not knobbed at apices...... 6 Thoracic respiratory organs not slender and tube-like, flattened and bub little.elevatedhn: te -siec ect ae is ces ERIOPTERINAE, pt. (p. 227). Thoracic respiratory organs long and usually tube-like, much ele- RU ALEC ect cena Ge E aon te RRA cN Pte Retele snare vise iate) Ake: se isha alors ee satin Sy0h 7 Abdomen without dorsal or ventral armature; thoracic respiratory organs not longer than width of thorax, slender and tube-like.... 7 Ea NESE PORL CORES CACORE COT Para ERIOPTERINAE, pt. (p. 227). Abdomen either with distinct armature on apices of dorsal segments or on both dorsal and ventral ones and with the thoracic respira- 210 tory organs longer than width of thorax; or if the armature of ab-. domen is very weak the thoracie respiratory organs are not tube- like but acute apically............... LIMNOPHILINAE” (p. 220). IMAGINES 1. Only one submarginal wing-cell present............-...eeeeeee 2 — Two submarginal wing-cells present..............0.00eeeeee Ae 2. .Antennae with 14 segments...............c00-se0s LIMNOBIINAE. —. Antennae: “with UGisepments:. Dicranota. — Ventral surface of apical abdominal segment without, or with very small, slender protrusive blood-gills; spiracles very small, situ- ated MpPONisMall elevations’ spine «)-). cca -s\-\ o's 6's « Rhaphidolabis. ro | PUPAE 1. Ventral abdominal segments without wart-like elevations; large species, more than 30 mm. in length................... Pedicia. 218 — Ventral abdominal segments each with a pair of wart-like eleva- tions; small species, not more than 20 mm. in length. . Dicranota. Pepicia Latreille I have not seen the immature stages of this genus, my informa- tion regarding them having been obtained from published descrip- tions. These justify the following generalizations for the larvae and pupae. GENERIC CHARACTERS Larva.—Head narrow, similar in general ‘structure to that of Dicranota (Pl. XXXIV, Fig. g), the dorsal surface compact, arcuate ; mandibles slender, the apical tooth long and pointed, inner lower margin with several smaller teeth; maxillary palpi longer and stouter than the antennae. Body with weak isolated hairs, or bare, the seg- ments distinct; ventral surface of segments 8-11 each with a pair of transverse pseudopods, the apices of which are not armed with spinules; apical segment with 2 long terminal processes, at the base of which, on the dorsal surface of the apical segment, are the spiracles on slight elevations; ventral anal blood-gills, when fully extended, as long as terminal processes. Pupa.—Differs from that of Dicranota in the absence of ventral protuberances. | HABITS OF LARVAE The larvae are aquatic and usually occur in still water—in springs or wells. They feed upon algae, diatoms, and small crustaceans. HABITS OF IMAGINES The flies of this genus are very large, and the wing-markings and conspicuously marked abdomen of the common species render their detection in nature very easy. Their flight is slow and heavy, and they seldom rise much above the level of the rank vegetation in the marshy or wet situations in which they normally occur. PEDICIA ALBIVITTA Walker Pedicia albivitta Walker, List of Diptera in British Museum Coll., Pt. I (1848), p. 37. Imago. . Tipulid sp.? Needham, Bull. 68 N. Y. State Mus., p. 285. (1903) Needham, in the bulletin cited above, described and figured the larva and pupa of this species. 219 The species is represented in our collection by an imago from New York State. DicrANota Zetterstedt I have the larva of one species of this genus, which is described herein. I have used Miall’s description of a European species as an index to the pupal characters of the genus, as this stage is unknown to me. The characters for the separation of the larvae of this genus from those of Pedicia and Rhaphidolabis are summarized in the synoptic key. DICRANOTA sp. ? Larva (Pl. XXXIV, Fig. 7)—Length, 10 mm. Whitish yel- low. Head black. Head long and narrow, posterior portion in the form of a compact arcuate capsule, the sutures poorly defined except in middle and on posterior margin (Pl. XXXIV, Fig. 9). Antennae long and slender (Fig. 6) ; maxillary palpi about the same length as antennae but much stouter (Fig. 5), the sensory area very distinct; mandibles long and slender, the apical tooth very acute, inner lower margin with 2-3 smaller teeth; labium divided centrally, each side with 3 sharp teeth, the median one of each trio smaller than the others. Segments of body well differentiated, clothed with close decumbent pile and with- out distinguishable bristles; 5 pairs of pseudopods on ventral surfaces of apical 6 segments exclusive of the last one, their apices armed with spines; spiracles situated on a pair of short processes at base of the prolonged apical protuberances; ventral blood-gills short, 4 in number. Described from a specimen taken by Dr. S. A. Forbes among weeds and stones in a stream on Bottlers Ranch, Yellowstone National Park, September 14, 1891. DICRANOTA BIMACULATA Schummel Dicranota bimaculata Schummel, Miall, Trans. Ent. Soc. London, 1893, pp. 235- 253. Larva and pupa. Prof. L. C. Miall published a detailed account of the life history and anatomy of this species in the paper cited above. In general the larva agrees with the one just described, the differences being found in the structure of the head. I have, however, to rely upon Miall’s de- scription and figures of the pupa for details of that stage. Pupa.—Thoracic respiratory organs elevated, rather stout, their 220 apices with truncated knobs. The abdomen is furnished upon the middle of the dorsum of the second and sixth segments with a rough-’ ened plate clothed with short coarse spines, and the intervening seg- ments each have 2 such plates, one before, and the other behind, the middle. Ventral segments 3—7 each with a pair of widely separated papilliform tubercles in a transverse line at middle. Apical segment elongate, without spines. This species is aquatic in the larval stage, but pupates in moist . earth along the banks of the streams in which the larvae occur. The larvae feed upon the worm Tubifex rivulorum. — RHAPHIDOLABIS Osten Sacken I have but one larva that I regard as belonging to this genus. It very closely resembles that of Dicranota, differing in being slightly more slender; in having the pseudopods armed with a more regularly curved semicircle of apical spinules, the spiracles much smaller and less elevated, the apical processes longer; and in the apparent absence of the ventral blood-gills. , This specimen was taken by Dr. S. A. Forbes among vegetable refuse in Blacktail Deer Creek, Yellowstone National Park, August 28, 1890. The larva of R. tenuipes has been figured by Needham*. The species are aquatic in the larval stage, occurring in streams. Subfamily LIMNOPHILINAE I have before me representatives of but one genus of this sub- family, and have found descriptions of but two others of the ten genera which it contains. SUBFAMILY CHARACTERS Larva.—Head well chitinized, much as in Tipula, the principal differences being the much longer maxillary palpi, which exceed the antennae in length, and the less robust mandibles. The labium also shows a departure from the tipulid type and is produced into a rather acute central point anteriorly, but the genera in which the structure of this plate is known to me differ materially, and a generalization is not justifiable, more particularly as both forms are found in other subfamilies. Apical abdominal segment with 4 or 5 protuberances on “Twenty-third Rep. N. Y. State Ent., p. 201. (1908) 221 margin of stigmatal field; ventral blood-gills present or absent. Body with short silky pubescence or bare; bristles absent. Pupa.—Head without chitinized protuberances; palpi straight. Thoracic respiratory organs long and slender, sometimes pointed apically. Legs extending much beyond apices of wings. Abdomen with weak armature, consisting of 1-3 transverse bands of weak spines and some longer slender hairs, or of only weak hairs, the seg- ments with the usual transverse incisions, giving them a divided ap- pearance. HABITS OF LARVAE The larvae of the genus Ula are fungivorous, living usually in Polypori; those of Limnophila and Epiphragma are aquatic or semi- aquatic, feeding upon algae and decaying vegetable matter, the last- named genus occuring in dead stems of plants. HABITS OF IMAGINES Most species of the subfamily fly in the evening, and they are not uncommonly attracted to lights. Krys To GENERA LARVAE 1. Apical segment with 2 long and 2 short processes which are fringed with very long hairs; labium divided centrally...... Limnophila. — Apical segment with 4 or 5 short, pointed processes which are in- conspicuously or not at all fringed.......................-.- 2 2. Apical segment with 4 processes..................- Epiphragma. — Apical segment with 5 processes.............cc eee cee cee eees Ula. PUPAE 1. Thoracic respiratory organs rather short, swollen at base and acute UPD DICCS Matera ce inka Oa chin nis se sales elt elers oe sei sve Epiphragma. — Thoracic respiratory organs long and slender, of nearly uniform thickness throughout their entire length, not acute at apices... .2 A numberof hairs on frons between antennae........ Limnophila. No hairs on frons between antennaec................000eeeee Ula. i) LimnopHiLa Macquart GENERIC CHARACTERS Larva.—Head moderately chitinized, the ventral, median posterior opening large. Antennae short and slender, with a long apical hair, 222 or 2 such hairs; frontal plates large; maxillary palpi longer and much stouter than antennae; labial plate divided in center, the lateral pieces’ digitate. Apical segment with 4 long processes which are furnished with long fringes; pseudopods absent. This description applies to aquatic forms only; the terrestrial forms are unknown to me. Pupa.—Palpi straight; antennae extending to or beyond bases of wings. Thoracic respiratory organs long and slender, least chitinized at apices; legs extending beyond apices of wings, disposed side by side. Abdomen with a number of transverse setigerous ridges on each dorsal and ventral segment, or with distinct tubercles in similar series. ; HABITS OF LARVAE The only larvae known to me are aquatic. The very long fine hairs on the apical abdominal segment take a very firm hold of the surface of the water when the processes which they border are ex- panded, and it requires considerable effort on the part of the larva to detach them in order to descend. Hart has stated that detachment is accomplished by throwing the cephalic extremity round in such a way that the thoracic segments pass over the apex of the abdomen, and thus their hold on the surface of the water is released. I have frequently seen the larvae do this, but only in water too deep for them to get hold of anything in the bottom. A considerable quantity of air is carried down within the confines of the fringes of the apical processes when the larva descends below the surface of the water, and when this is exhausted the larva ascends for a fresh supply. In cases where the specimens are able to feed without entirely submerging the body, the apical segment is expanded on the surface of the water and forms a conspicuous crater-like cavity within which are visible the eye-like anal spiracles. The food consists of decaying vegetable matter and algae. I have found the larvae common at Muncie and White Heath, IIl., but only along the margins or in the muddy banks of streams. I have reared two species, but the larva of only one of them has been associated with the pupa and imago. LIMNOPHILA LUTEIPENNIS Osten Sacken Limnophila luteipennis Osten Sacken, Proc. Acad. Nat. Sei. Phila., 1859, p. 236. The larva and pupa are described by Hart in the paper frequent- ly cited herein*, and the following details should be accepted as sup- plementary to that description. *Bull. Til. State Lab. Nat. Hist., Vol. 4, Art. VI, pp. 202-204. 223 Larva (Pl. XXIX, Fig. 4).—Length, 15-18 mm. Yellowish tes- taceous or slightly olivaceous. Head dorsally as in Figure 7, Plate XX XIII, the antennae short and slender (Pl. XX XIII, Fig. 2) ; mandibles as in Figure 15, Plate XXXIII, being quite different in form from those of Hexatominae and more resembling those of Limnobia; labium (Pl. XXXIII, Fig. 3) divided in center, each half with 7 teeth; maxillary palpi with 3 joints. Body with rather conspicuous surface hairs which are situated on slight transverse ridges; apical segment (Pl. XXX, Fig. 1) with 2 short upper and 2 long lower processes which are fringed with very long hairs; ventral blood-gills 4 in number. Pupa (Pl. XXIX, Fig. 5).—Length, 10-13 mm. Color as in the larva. Thoracic respiratory organs (Pl. XXXIII, Fig. 18) slightly long- er than wings, their apices split; legs ending in a straight transverse line at apex of second abdominal segment; each dorsal abdominal seg- ment except basal with 5 transverse series of hair-like bristles set on small chitinized elevations which form slight ridges, the posterior pair much more widely separated than the others. Ventral segments with 6 such transverse series arranged as on dorsal segments. Apical segment of female composed of 2 pairs of elongate processes which form an acute tip, the lower pair two thirds as long as the upper. This species is probably present in every stream and river in the state, as I have found it wherever I have collected in March and April. LIMNOPHILA TENUIPES Say Limnophila tenwipes Say, Jour. Acad, Nat. Sci. Phila., Vol. 3, p. 21. (1823) I have obtained only the pupa of this species. It resembles luteipennis in general shape and in the arrangement of the cephalic and thoracic appendages, but in the armature of the abdomen there is a notable difference. Pupa.—tLength (exclusive of the respiratory organs), 10-15 mm. Blackish brown. Thoracic respiratory organs rather more slender than in /uteipen- nis. Abdominal segments, exclusive of the basal dorsal, those covered by the legs, and the apical one, each with 3 transverse pairs of widely separated protuberances, the distance between those of each series less than the distance from either to the lateral margins; distance between the most posteriorly placed pair and posterior margin of segment greater than the distance between the pairs; posterior margin with 224 4-6 smaller protuberances which, like the others, are armed at apices, with 1-2 weak hairs; lateral margins with a tubercle at a point cor- responding to the situation of the dorsal and ventral transverse series ; apical segment of male and female as in Figures 8 and 9g, Plate XXXIII. I collected a large number of pupae of both sexes of this species on the banks of the Sangamon River at White Heath, Ill, May. 28, 1916. I found that by taking mud from the bank and disintegrating . it in the water I could readily obtain the pupae as they floated at the surface. The species is common in Illinois, and probably occurs in most of its streams. ‘The pupa was described by Mr. Hart as Lim- noplula species (a) in his paper previously referred to. EpirpHRAGMA Osten Sacken I have not seen the early stages of this genus, but those of fasci- pennis have been described by Needham, as indicated in the synonymy under the species name, GENERIC CHARACTERS Larva.—Details of the cephalic structure are lacking in Needham’s description, and as I have no means of ascertaining these, only the superficial characters can be indicated. Body cylindrical, without sur- face hairs or bristles; ventral pseudopods represented by fusiform ventral areas; apical abdominal segment with 4 short marginal processes and 4 slender protrusive ventral blood-gills. Pupa.—Thoracic respiratory organs much shorter than in Lim- nophila and Ula, and more horn-like than tube-like, their apices in- curved and acute. Legs extending beyond apices of wings the length of 2 abdominal segments, terminating in an almost straight transverse line. Abdomen without thorn-like armature, only bristly hairs present at apices of segments. EPIPHRAGMA FASCIPENNIS Say Limnobia fascipennis Say, Jour. Acad. Nat. Sei. Phila., Vol. 3, p. 19. Imago. (1823) Epiphragma pavonia Osten Sacken, Proce. Acad. Nat. Sci. Phila., 1859, p, 239. Imago. Epiphragma fascipennis Say, Osten Sacken, Mon. N. Am. Dipt., Vol. 4, p. 194. Imago. (1869) Epiphragma fascipennis Say, Needham, Bull. 68, N. Y. State Mus., p. 281. Larva and pupa, (1903) 225 Larva (Pl. XXXV, Fig. 2).—Length, 19 mm. White, or faintly tinged with yellowish. Head large for the family. (No structural description given by Needham.) On the ventral side of the three thoracic segments is a pair of minute brownish points. Ventral side of segments 2-7 each with a single median proleg—a mere soft, white, transversely placed ridge, without hooks or claws. The abdomen is without other tuber- cles, spines, or hairs. Spiracles large, widely separated. Spiracular disc with 4 thick marginal processes, the upper pair blunt apically, fringed with hairs, and separated by the full width of disc, the lower pair a little more pointed and a little closer together (Pl. XXXV, Fig. 3). Anal blood-gills slender, 4 in number. Pupa (Pl. XXXV, Fig. 9).—Length, 12 mm. Ventral view and general appearance as in figure. Apical carina on each abdominal segment fringed with short stiff hairs, those on the ventral side of eighth segment more comb-like, and interrupted on the median line in female. The foregoing descriptions are abridged from Needham’s paper, and the accompanying figures are copied from the same author. The materials used by Needham in making his descriptions were obtained at Lake Forest, Ill., where the larvae were found boring in the dead stems of buttonbush and willow lying on the mud at the borders of shallow pools. The species is represented in our Laboratory collection by imagines from Algonquin and Urbana, Ill., and from Philadelphia, Pa., all be- ing taken in June. Uta Haliday GENERIC CHARACTERS Larva.—Body cylindrical, without hairs; pseudopods faintly in- dicated in the form of slight transverse ventral fusiform areas on apical portion of abdomen. Labium entire; maxillary palpi longer than the rather stout antennae. Apical abdominal segment with 5 processes on margin of spiracular disc. Pupa.—General appearance similar to that of Limnophila, but the armature of the abdomen differs noticeably in being confined to the posterior margins of the median dorsal segments. ULA ELEGANS Osten Sacken Ula elegans Osten Sacken, Mon. N. Am. Dipt., Vol. 4, p. 276. Imago. (1869) Ula elegans Osten Sacken, Alexander, Pomona Jour. Ent. and Zool., Vol. 7, pp. 1-8. (1915) 226 Larva.—Length, 8.5-11.9 mm. White, the head brownish black, shining. Antennae short and stout, armed at apices with 2 short processes; labium with a small central tooth, the first lateral on each side dis- tinctly larger and extending anteriorly beyond the apex of the central one, sides of plate sloping abruptly backward, armed with 3 teeth; mandibles stout, their inner margin with 2 teeth in addition to the apical one. Apical abdominal segment with the dorso-central process . small, the lateral much longer and slightly more pointed than the latero-ventrals, all fringed with marginal short hairs and each with conspicuous black mark on the posterior surface; anal blood-gills ab- sent. Pupa.—Head without anterior protuberances, Palpi curved slight- ly forward at their apices. Thoracic respiratory organs long and slender, dark basally, pale apically; legs extending to middle of fourth segment beyond apices of wings. Dorsal abdominal segments 2-6 each with a noticeable transverse subchitinized band of a sha- greened texture; the disc of segments with small setigerous punctures. The above descriptions are abridged from Alexander’s, reference to which is given under species name. Alexander’s material was ob- tained at Ithaca, N. Y. The larvae feed in fungi, elegans being taken in a species of Fomes (Polyporus) growing on a tree-stump. The imagines emerged in September and October. The species occurs throughout the Atlantic states and is recorded from Wisconsin, so that it probably occurs in Illinois though we have no record of it. Subfamily RHAMPHIDIINAE The only information I have regarding the larval and pupal stages of this subfamily is that contained in the description of the European species Elliptera omissa. The larvae of Rhamphidia longirostris has been found by Gercke, but he did not describe it. The characters of the larva and pupa of Elliptera as indicated by Mik are given below. One species of this genus, clausa Osten Sacken, occurs in North America. ELLIPTERA OMISSA Egger Elliptera omissa Egger, Verh. d. zool.-bot. Ges., Vol. 13, p. 1108. Imago. (1863) ELlliptera omissa Egger, Mik, Wiener Ent. Zeit., 1886, p. 337. Larva and pupa. Larva.—Length, 7 mm., breadth, 1.5 mm. More robust than most members of the family, the segments distinctly broader than long. 227 ‘Head heavily chitinized, dorsum with the usual 2 longitudinal dor- sal excisions and a smaller median posterior one. Antennae short and slender. Labium heavily chitinized, triangular in outline, margin den- tate. Mandibles strong, curved, their inner margin dentate. Body slightly flattened dorso-ventrally, the segments distinct, with decum- bent pale pile, and having long bristle-like hairs on lateral margins of each segment, 1 on the prothorax and 2 on each of the other seg- ments. Abdominal segments 2-8 each with a narrow transverse fusi- form stripe on ventral and dorsal surfaces near the anterior margins which is armed with short spinules. Apical segment tapered, cleft, the margins of the cleavage with 2 upper and 2 lower processes, each pair margined with fine hairs. Pupa.—Length, 6.5 mm. Yellowish brown, the abdomen green- ish white. Thoracic respiratory organs about as long as diameter of thorax, very stout, their bases almost contiguous, tapering from base to apex, and more or less resembling the pincers of a crab. Abdomen armed as in larva except that the lateral hairs are wanting. Legs extending to base of antepenultimate abdominal segment. Apical segment pro- longed slightly in both sexes, that of the female a trifle the longer, a few small processes present in both sexes at base. This genus agrees well in the larval and pupal stages with the cor- responding stages of Dicranomyia, the distinctions between them be- ing less marked than is the case with allied genera of some other sub- families. Subfamily ERIOPTERINAE Helobia and Gnophomyia are the only genera of this subfamily of which identified larvae and pupae are before me. I have, however, an unidentified larva that quite obviously belongs here. There is a great similarity in these larvae, but judging from the available descrip- tions of European species of other genera a great difference exists between the forms I have and those of other European genera. The description of the larva of Trimicra agrees with the characters gen- erally attributed to larvae of Pediciinae—a fact that to my mind throws considerable doubt upon the correctness of the present sub- family-grouping, which is based upon characters of the imagines. I have no intention of rearranging the genera in this or any other sub- family upon the basis of characters deduced from printed descrip- tions, and accordingly leave the subfamilies practically as in Willis- ton’s “Manual”, but consider it essential to indicate the probability of errors in the arrangement. 228 I do not include in the following synopsis of characters, nor in my, keys, genera which I do not possess, though they may have been de- scribed by other authors; but notes upon Erioptera are given in the text owing to the existence of a previous record of the occurrence of a larva of that genus in Illinois. SUBFAMILY CHARACTERS Larva.—Slender, cylindrical, tapering slightly towards both ex- tremities, the body covered with dense decumbent pile. Head small, poorly chitinized ; labium unchitinized ; the main portion of head con- sisting of slender chitinized rods, 4 or 6 in number. Pupa.—Head as in Limnobiinae, without projections; palpi straight; directed laterad. Thoracic respiratory organs short, or if of considerable length, still noticeably shorter than those of Limnoph- ilinae known to me, and of a uniform strength throughout; legs longer than wings. Abdomen with weak armature, which is not in the form of transverse bands or series of spinules; spiracles distinct. Imago.—See key to subfamilies. Krys To GENERA LARVAE 1. Body with almost indistinguishable surface hairs; ventral surface of abdominal segments without distinct transverse pseudopod- like: swellimes: we cen secretin pater rset Helobia punctipennis. — Body covered with rather long and very dense decumbent hairs which give the larva a silky appearance; ventral surface of ab- dominal segments with distinct transverse pseudopod-like swell- That: eae Sty NOMEN O'S SUIS Oia coe BS é Gnophomyia tristissima. PUPAE 1. Thoracic respiratory organs pressed close against surface of thorax; legs extending very slightly beyond apices of wings (Pl. XXVIII, 1 hivegen la) Paes oe Goce c cao mo oo doc ts oc Gnophomyia tristissima. — Thoracic respiratory organs erect, tube-like, not pressed against sur- face of thorax; legs extending very far beyond apices of wings. . Peale tticrr lie Boooetar Seis ote meee aimtdard Gtr orbrs wrth Helobia punctipennis. Hetosia St. Fargeau GENERIC CHARACTERS Larva.—Cylindrical, slightly tapering towards the extremities. Head small, entirely retractile, caudad of mandibles consisting of 6 229 chitinized rods with weakly chitinized connecting membrane. Body with very indistinct surface pilosity. First thoracic segment with an indistinct transverse median division. Abdominal segments 2—7 with a median transverse constriction or division. Apical segment with 5 stout protuberances. Pupa.—Differs from the pupa of Gnophomyia in the structure of the thoracic respiratory organs, which are slender and elongate. The legs also are more elongate than in Gnophomyia. HABITS OF LARVAE The larvae are found in mud and sand along the margins of streams. They burrow in the wet sand and are able to live under water like the larvae of Limnophila, though they are less commonly found there. HABITS OF IMAGINES The imagines are very common throughout Illinois and usually fly in the late afternoon. They are readily attracted to lights at night. They may feed upon nectar, but the mouth parts are poorly developed. Our species occurs also in Europe. HELOBIA PUNCTIPENNIS Meigen Limnobia punctipennis Meigen, Syst. Beschr. Eur. Zweifl. Ins., Vol. 1, p. 17. (1818) Larva (Pl. XXIX, Fig. 6).—Length, 8-10 mm. Pale yellowish testaceous. Head (Pl. XXXIV, Fig. 18) poorly chitinized, the posterior por- tion consisting of slender blackish rods, the intervening spaces filled with weakly chitinized membrane; antennae short, 2-jointed, the apical joint very short; maxillary palpi longer than antennae and much stouter; mandibles stout, their lower margin toothed (Pl. XXXIV, Fig. 11); labium apparently not chitinized, indistinguishable in my specimens. Body covered with short decumbent pile, which is less. conspicuous than in the other larvae of this subfamily. Segments with the usual transverse linear incision on dorsum; apical segment as in Figure 17, Plate XXXIV. Pupa (Pl. XXIX, Fig. 7).—Length, 7-9 mm. Color as in the larva. Thoracic respiratory organs tube-like, from 6 to 8 times as long as their greatest diameter; prothorax flattened, declivitous, with an elongate, rather broad foveate mark on each side of dorsum; anterior margin of mesothorax with a slight ridge-like swelling, upon which are 230 numerous small spinules and, laterally, 2 or more small tubercles; legs, extending well beyond apices of wings, apices of fore tarsi extending beyond apices of mid pair, apices of hind pair extending beyond apices of fore pair. Abdomen without noticeable armature; apical segment of female elongate, the upper processes longer than the lower, that of male obtuse, with 7 slight protuberances, 3 in a transverse line be- fore apex on dorsum and 4 at apex—2 above and 2 below, the latter acute. The material used in drawing up the foregoing descriptions is that which Mr. Hart had when he wrote his paper on Illinois River species. He did not describe the early stages, referring merely to Beling’s de- scription of them which appeared in a European publication. GnopHomyIiA Osten Sacken GENERIC CHARACTERS Larva.—Head rather small, wholly retractile, posteriorly com- posed of slender chitinized rods. Body covered with dense silky _ hairs. General form similar to that of Helobia, the principal differ- ences being the much less conspicuous hairs on the surface of the lat- ter, the absence of distinct ventral locomotor organs, and the longer radiating processes of the apical segment. Pupa.—The structure of the thoracic respiratory organs suff- ciently distinguishes this genus from Helobia. HABITS OF LARVAE The larvae live in mud, especially along the banks of streams. HABITS OF IMAGINES The flies are usually found in damp situations, especially in grass along the margins of ponds or streams. They feed on nectar or liquids. GNOPHOMYIA TRISTISSIMA Osten Sacken Gnophomyia tristissima Osten Sacken, Proc. Acad. Nat. Sci. Phila., 1859, p. 224. Larva.—Length, 9-11 mm. Slender, slightly tapering towards both extremities, more decidedly towards the cephalic. Body yellow- ish testaceous, covered with dense decumbent pile. Head more compact than that of Helobia, the lateral rods stouter (Pl. XXXIV, Fig. 10); antennae very small; maxillae large, pro- 231 duced beyond the apex of the narrow labrum, the palpi stout; labium not chitinized; mandibles slender, with a long sharp apical tooth and about 3 poorly defined teeth along the lower lateral margin. Loco- motor organs consisting of rather broad fusiform areas on anterior portion of abdominal segments except basal and apical; hairs along margins of segmental incisions more distinct than elsewhere because of their being slightly curved upward; apical segment with 5 processes, their structure and markings as in Figure 16, Plate XXXIV; anal ventral blood-gills in the form of 4 short rounded protuberances. Pupa (Pl. XXVIII, Fig. 15).—Length, 8-10 mm. Color as in larva. Thoracic respiratory organs very little elevated, in the form of longitudinal ridges very similar to those of some Tabanidae. Protho- rax not so decidedly declivitous as in Helobia. A very long hair on each side of thorax just above and slightly in front of base of wing; front view of thorax and appendages as in Figure 15, Plate XXVIII. Lateral margins of abdomen with long hairs situated upon slight eleva- tions, as shown in figure last mentioned; spiracles larger than in most genera in the family, 6 pairs distinct; apical segments of male and female as in Figures 16, 17, and 18, Plate XXVIII. The foregoing descriptions are made from specimens supplied by J. A. Hyslop and taken at Wolfville, Md., May 20, 1913. The larvae are found in wet mud along the banks of streams or other bodies of water. The species is common in Illinois. ERIopTERA Meigen The larvae of two European species of this genus have been de- scribed by Beling. He does not appear to have paid much attention to the structure of the head of any larva that he described, the only characters mentioned being those of general shape, armature, or clothing of the body, the absence or presence of pseudopods, and the shape of the apical segment. The species, judging from his descrip- tion, differ from those of allied genera in having the thoracic segments distinctly swollen and the body noticeably tapered posteriorly. The apical segment is armed with 5 short processes as in Gnophomyia and Helobia. The species described by Hart as Erioptera species (a) in his paper on the Entomology of the Illinois River, is not an Hrioptera accord- ing to this generalization, but is, I think, much more closely related to Gnophomyia than to Elliptera, contrary to Mik’s opinion*. I figure *Wiener Ent. Zeit., Vol. 16, 1898, p. 62. 232 the head of this species and briefly describe it on a subsequent page . of this paper under the heading Genus incertus 2. Subfamily HEXATOMINAE SUBFAMILY CHARACTERS Larva (Pl. XXXIV, Fig. 14).—Very slender; aquatic or semi- aquatic. Head flattened, not so heavily chitinized as in other sub- families (Pl. XXXIV, Fig. 12). Maxillae with a long, slender, pointed process at outer anterior angle, the processes having been er- roneously designated as maxillary palpi by some authors. Antennae short and slender. Labial plate not chitinized, indistinguishable. Mandibles long and slender, sickle-shaped, the teeth confined to base or basal half of inner surface. Body without distinct pseudopods, usually covered with silky hairs; apical segment terminating in 4 slender processes which are fringed with long fine hairs (Pl. XXXIV, Fig. 13). Pupa.—Head produced in the form of 2 wart-like protuberances at bases of antennae, bases of the latter, especially in male, swollen, their apices extending to or beyond apices of wings. ‘Thoracic respira- tory organs long and. slender, sometimes acute apically; legs extend- ing well beyond apices of wings. Abdomen with a few weak hairs, the segments, except the basal one, usually with a preapical dorsal transverse band of small spinules. HABITS OF LARVAE The larvae of this subfamily are aquatic, but usually, as is the case with other aquatic Limnobiidae, they pupate in the mud alongside the stream in which the larvae occurred. The food consists of algae and vegetable debris. HABITS OF IMAGINES The imagines of this subfamily which we have observed, are most active in the late afternoon, flying in swarms over streams or along their margins. Usually they are sluggish, and may be swept from rank herbage along stream margins. I do not know their food-habits. Krys To GENERA LARVAE 1. Lower process on each side of apical abdominal segment with a very long terminal hair in addition to the fringe of short hairs along TAL AT PUN ce ves ween Oe ehToNe otete rete Make Ris eee ee ee Penthoptera. 233 — Lower process on each side of apical abdominal segment with only the fringe of short hairs, no long terminal hair being present. . .2 2. Labrum with a leaf-like lobe on each antero-lateral angle which is directed anteriorly and mesad, the pair almost meeting so as to shield the anterior margin of the labrum............ Hexatoma. — labrum either rounded or but slightly produced at the antero-later- al angles, lobes, if present, not directed mesad, and the apices Ol the pair widely Separated( se. sctsce ccc 6s ce sees cles Eriocera. PUPAE 1. Apices of fore tarsi ending much proximad of apices of mid and HUNG aT CUUIES eee eats Ae ree SENS speci ate: « locouRonabaie os clecuske loots Hexatoma. — Apices of fore tarsi ending on a transverse line with mid pair, the hind pair sometimes extending distad of the latter............ 2 2. Thoracic respiratory organs very noticeably swollen at bases and ap- ices, the constricted central portion with transverse wrinkles... . Scio ESR OO CU EES te AOR AHO On BE De rn EP ana Penthoptera. — Thoracic respiratory organs of nearly uniform thickness throughout their length, sometimes tapering from near base to apex........ Ae eh ba Par ao ieee eR PRE oe te Pe eh tee Se TOC Ora: I have before me a number of larvae of this subfamily, but can as- sociate none of them with a described species as neither pupa nor imago are in the collection. Our specimens, with but one exception, were obtained by Dr. S. A. Forbes in rivers in Yellowstone National Park; the single one was taken by Dr. C. C. Adams in Montana. The species in their larval stage appear to be confined to swift-flowing streams. No examples have been obtained in Illinois though much careful work has been done on the Illinois River. It is not improbable that an ex- amination of some of the smaller swift-flowing streams in the more hilly sections of the state will discover the presence of these larvae. They are usually found under stones when in the current, but come ashore to pupate in the sand or mud of the banks. The species almost invariably have the appearance of Figure 14, Plate XXXIV, when preserved, the integument of the penultimate segment distending remarkably in some specimens. Brauer, in his paper previously referred to, has figured a species with this charac- teristic distension. The !ong membranous appendages of the maxillae probably serve the purpose of guiding the food into the mouth, being analogous to the mouth-fans of the family Simuliidae—also found in swift-flowing waters. 234 Subfamily TRICHOCERINAE I have before me a single specimen of the larva of a species of Trichocera. ‘The pupa is unknown to me. In many respects the larva resembles that of Rhyphus, but the affinities of the imago are clearly with the Limnobiidae, and for this reason I retain it here, though with some hesitation. TRICHOCERA Meigen GENERIC CHARACTERS Larva.—Head different from that of all other Limnobiidae in having a complete capsule, closely resembling in this respect Ptychop- teridae and Rhyphidae, the ventral surface especially resembling that of the latter; mandibles stout, with distinct teeth. Body covered with decumbent pile. Prothorax with distinct spiracles. The apical seg- ment is noticeably more slender than the preceding one and armed with 4 finger-like processes surrounding the spiracles. Pupa.—Head and thorax with hairs much as in Rhyphidae, the ~ cephalic hairs very similar to those of Limnophila. The thoracic re- spiratory organs are horn-like. The abdomen is armed as in Limnoph- ila and has incisions similar to those present in that genus. Imago.—See key to subfamilies. HABITS OF LARVAE The larvae are found in decaying vegetation and under leaves. HABITS OF IMAGINES The genus Trichocera contains the so-called “winter-gnats” of Europe. They fly in mild weather throughout almost the entire winter in Britain, and are frequently seen flying over snow and settling upon it where the sun falls on it. It is remarkable that this very common genus is unrepresented in the materials in our Illinois collection. TRICHOCERA Sp.? Larva (Pl. XXXVI, Fig. 1).—Length, 7.5 mm. Pale testaceous, the head with brown marks on each side of central sclerite of dorsum in front of antennae, and along posterior margin. Antenna small, consisting of a slender apical process situated on 235 an elevated base; mandibles similar to those of Rhyphidae in that they consist of a stout basal piece and an articulated apical one, the latter with several teeth; labium small, rounded anteriorly, the appendage above it (mentum) similarly shaped, both armed with numerous hairs (Pl. XXXVI, Fig. 10); labrum overhanging oral orifice, the epi- pharynx armed with numerous strong spinules; maxillae and their palpi similar to those of Rhyphus punctatus ; eyes pigmented, situated on side of head instead of being on dorsum as in Rhyphus. Body with short decumbent pile; segments of thorax bisected, those of ab- domen trisected ; pseudopods absent; apical segment with 4 finger-like processes, the lower pair longer than the upper and furnished with some delicate hairs at apices. The specimen described above was taken by A. G. Whitney on St. Paul Island, Bering Sea, March 23, 1913, and formed part of a col- lection submitted to me for identification by the U. S. Bureau of Bio- logical Survey. LIMNOBIID LARVAE OF UNCERTAIN GENERIC LOCATION I have based the synoptic key to the larvae of the subfamilies upon species that I have reliable identifications for, but certain larvae that I have before me are not in agreement with the characters cited, or they so vaguely resemble those that are identified as belonging to the various subfamilies that I have deemed it wisest to describe them in- dependently, in the hope that further light may be shed upon their position in the classification by some student of the group who may succeed in rearing them. I realize that there are in store for us many surprises in the larval and pupal characters of species that are as yet unknown in these stages, and hope that the present effort to assign characters for the separa- tion of the subfamilies may be improved upon rapidly after it appears in print. GENUS INCERTUS I Larva (Pl. XXXV, Fig. 11).—Length, 10 mm. Golden yellow, covered with silky hair which gives the larva a satiny appearance. Ta- pering on thoracic segments towards head. Head almost completely re- tractile, ventral aspect as in Figure 16, Plate XX XV; oesophagus con- spicuous, its sides with very prominent ridges which meet angularly in center; maxillary palpi 2-jointed, of moderate size; mandibles bare- ly distinguishable in mount (see figure last mentioned); posterior portion of head consisting of 4 rods, the dorsal pair more elongated 236 than the ventral and thickened apically. Thorax and abdomen dense- ly covered with closely appressed silky pile; dorsum of thoracic and abdominal segments each with a transverse series of short, closely placed, backwardly directed spines at suture, the abdominal segments with 3 additional transverse series which do not traverse the whole dorsum and are usually interrupted in one or two of the series; ven- tral segments each with 2 transverse series of similar locomotor spines on all but the apical 4, these latter bearing a series at the sutures and - a transverse mouth-like incision with slightly protruded membranous integument which is densely clothed with short upright hairs (PI. XXXV, Fig. 14); hairs in front of the transverse incision on apical segment very long; locomotor spines barely distinguishable except when the larva is alive and in motion; apical segment terminating in 4 rather long stout processes, on the inner under surface of the upper pair of which are the black, round, posterior spiracles, and on the lower pair a long apical hair (Pl. XXXV, Fig. 13). The larva just described is one that I took from a much-decayed log at White Heath April 30, 1916. It conforms to the general characteristics of the larvae of this family, but I have no means of determining its specific identity as the only specimen I obtained died before pupation. The head and thoracic segments were dissected and mounted in Canada balsam; the remainder preserved in alcohol. The structure of the head points to the likelihood of the species belonging to Eriopterinae. GENUS INCERTUS 2 Larva (Pl. XXXIV, Fig. 8).—Length, 5-7 mm. Yellowish white, with the head and locomotor areas showing blackish. Head as in Figures 1, and 4, Plate XXXV, the general shape re- sembling that of Limnobia; mandibles stout, with apical and lower marginal teeth; labial plate of the same form as in Limnobia. Body slender, the segmentation distinct; locomotor organs consisting of transverse, elevated, slightly leathery areas which are not armed with spinules, their number and arrangement as in Figure 8, Plate XXXIV. Apical segment terminating in 2 long tapering processes which are armed with a number of long hairs, as in Figure 15, Plate XXXIV. Spiracles situated on dorsum at base of terminal processes, their open- ings not conspicuous nor chitinized. Described from 4 specimens obtained by Dr. S. A. Forbes from Firehole River below Nez Perce Rock Rapids, Yellowstone National Park, August 16, 1890. 237 The description of the larva of Trimicra pilipes Meigen is not un- like that of the present species, but in the former the locomotor organs consist of paired pseudopods, and it is probably a true pediciine species, whereas the one above described may prove to be an aberrant limno- biine, resembling Pediciinae only in the structure of the apical seg- ment. GENUS INCERTUS 3 This is the larva described and figured by Mr. Hart as Erioptera species (a). Judging from the characters of the larvae of Erioptera summarized on a previous page this species does not belong to that genus. The head is quite different from that of Helobia, the dorsum being much more compact, as is shown in Figure 19, Plate XXXIV. I believe that the species really belongs to Eriopterinae, as the super- ficial characters ally it more closely with that subfamily than with any other. The larva and its apical segment are shown in Figure 8, Plate XXIX, and in Figure 5, Plate XXX, respectively. For a full description of the species see Mr. Hart’s description*. The larva lives among floating weeds, in the Illinois River. GENUS INCERTUS 4 Larva.—Length, 15 mm. Slender, the segments distinctly longer than broad, the body of almost uniform thickness. Head very similar to that of Helobia, the median posterior rod even more slender than in that genus; dorsal plate (fronto-clypeus) longer and more slender and pointed than in Helobia; maxillary palpi tapering, extending very much beyond the apex of labrum, with dis- tinct constrictions on apical third, giving them the appearance of hav- ing 3 joints. Body covered with dense yellow decumbent pile, most conspicuous at posterior margins of thoracic segments because there it is slightly turned upward. Abdomen without distinct locomotor organs; penultimate segment swollen much as in Hexatominae; apical segment with 4 short backwardly directed protuberances, the upper pair distinctly shorter than the lower; anal blood-gills inconspicuous. The foregoing description was made from a specimen in the Laboratory collection bearing the accession number 26785, the ac- companying data being as follows: Blacktail Deer Creek, Yellow- stone National Park, August 28, 1890; taken under stones in the water (S. A. Forbes). *Bull. Tl. State Lab. Nat. His. Vol. 4, Art. VI, pp. 198-199. 238 This species closely resembles Genus incertus 1 of this paper in head-structure and appearance, differing however in the absence of pseudopods. It undoubtedly belongs to the Eriopterinae. PAPERS ON THE Brotocy or NortH AMERICAN LIMNOBUDAE* Cylindrotominae Alexander, C. P. 14. Biology of the North American crane flies (Tipulidae, Dip-~ tera). II. Pomona Coll. Jour. Ent. and Zool., 6:105. (Con- tains full bibliography of the immature stages of the group. : Osten Sacken, C. R. 69. Monographs of North American Diptera. Part IV, p. 296. (Contains synopses of genera and species of imagines.) Limnophilinae Alexander, C. P. ’15. The biology of the North American crane flies (Tipulidae, Dip- tera). III. The genus Ula Haliday. Pomona Coll. Jour. Ent. and Zool., 7:1. : Hexatominae Alexander, ‘C. P. 714. . The biology of the North American erane flies (Tipulidae, Dip- tera). I. The genus Hriocera Macquart. Pomona Jour. Ent. and Zool., 6:12. 15. The biology of the North American crane flies. IV. Tribe Hexatomini. Pomona Jour. Ent. and Zool., 7: 141. Family PTYCHOPTERIDAE FAMILY CHARACTERS Larva.—Head complete; mandibles opposed. Body long and slender, with well-developed pseudopods armed with spines or bristles ; many of the hairs on head and body plumose; larva metapneustic, the tracheae extensile, in the form of a long slender membranous tube. Pupa.—Thoracic respiratory organs very unequal in length, one many times as long as the other; fore tarsi overlying mid pair. Imago.—Separable from Tipulidae and Limnobiidae by the ab- sence of the seventh longitudinal wing-vein,-and the rather poorly de- fined mesonotal suture. *See also papers listed in the bibliography of Tipulidae. 239 HABITS OF LARVAE The larvae are found in damp situations, frequently in water, and feed upon decaying vegetation and algae. HABITS OF IMAGINES The imagines are usually found near streams or other bodies of water. They are frequently taken upon flowers. Several species of Ptychoptera are common in Europe, but they are much less so in North America, occurring but rarely in Illinois, Key To GENERA LARVAE 1. Body with transverse series of wart-like elevations surmounted by hairs; ventral cephalic sclerite conspicuously narrowed posteriorly OD DO CERO pace Ba eI OES ODA CIR Fic aed ane Bittacomorpha. — Body without transverse series of wart-like elevations, but armed with hairs in transverse series; ventral cephalic sclerite slightly MATTOWEO POStELIOLI Ys. «cae cei oe ot cars os cies cas Ptychoptera. BirTacoMoRPHA Westwood This genus is represented by many examples of clavipes, in all stages, in the collection before me. This material was used by Mr. Hart in drawing up his description of the larval and pupal stages in the paper frequently mentioned herein. The superficial characters of the larva and pupa are well illustrated by Figures 4 and 6, Plate XXX. The following description should be regarded as supplementary to the .previously published one. BrrTACOMORPHA CLAVIPEs Fabricius Tipula clavipes Fabricius, Mantissa Insectorum, Vol. 2, p. 323. (1787) Larva (Pl. XXX, Fig. 4).—Length, including extended respira- tory tube, 50-60 mm. Pale brownish, with the dorsal surface of head marked with dark brown granulose elevations, and the transverse series of warts on body darker than remainder of ground-color (PI. XXXV, Fig. 5). Ventral surface of head as in Figure 8, Plate XX XV, the central sclerite very much narrowed posteriorly, the anterior margin. con- cave; maxillary palpi and antennae longer than in Ptychoptera; labrum seen from above about half as long as broad; mandibles as in 240 Figure 15, Plate XXXV, a strong tooth on outer surface much be- fore apex. ‘Three pairs of distinct ventral pseudopods present, one on the posterior margin of each of the basal 3 abdominal segments, each pseudopod armed with a strong curved apical claw that may be retracted at will (Pl. XXX, Fig. 2); two protrusive blood-gills at base of respiratory tube. Pupa (Pl. XXX, Fig. 6).—Length, inclusive of respiratory organ, 50-60 mm, Color like that of larva. : One thoracic respiratory organ very long, usually longer than body, the other aborted. Palpi very long, curved forward; antennae shorter than in Tipulidae and but little curved; fore tarsi concealing a portion of mid pair; arrangement of parts as in Figure 6, Plate XXXV. This species is aquatic, living among floating vegetable debris. The imagines have been taken in various parts of the state, but the only Laboratory record for the larvae is Havana, on the Illinois River. PrycHopTEeRA Meigen I have found in the collection here a number of larvae of Ptychop- tera taken more than twenty-five years ago by Dr. S. A. Forbes. As the species was not reared and the pupal stage is not in the collection, I am unable to compare the pupae of the genera or to give a specific identification for the form before me. PTYCHOPTERA Sp.? Larva (Pl. XXXV, Fig. 12).—Length, 18-20 mm. with anal re- spiratory tube retracted. Differs noticeably from the larva of Bittacomorpha in the structure of the head and body, none of the cor- responding parts of the two genera bearing more than a general re- semblance to each other. The ventral sclerite of the head is very much broader than in Bittacomorpha and does not narrow so decided- ly posteriorly ; the mandibles differ from those of B. clavipes in hav- ing a number of stout spines on their outer surface before apex instead of a very strong tooth; the labrum is about 4 times as broad as long; and the surface of the head is smooth and almost unicolorous. A com- parison of Figures 7 and 10, Plate XXXV, with those of Bittacomorpha (Pl. XXXV, Figs. 5, 8) will illustrate the main dis- tinctions between the genera. The body differs from that of Bittacomorpha in lacking the transverse series of wart-like elevations that are so conspicuous in that genus. 241 The two lots of larvae from which the foregoing description was made, were collected by Dr. Forbes in Yellowstone National Park in 1890, one on August 8, in Yellowstone Lake, and the other on August 13 in Alum Creek, both collections being obtained among weeds. Family RHYPHIDAE This family is very small, containing only three genera from North America. One of these, Mycetobia, has been but lately assigned to the family, having previously been regarded as belonging to the Mycetophilidae. According to the differentiating characters previous- ly considered by taxonomists as of family value, Mycetobia appears to belong to Mycetophilidae rather than to Rhyphidae; but the larval and pupal characters unmistakably ally it very closely with Rhyphus. The early stages of Olbiogaster are not known to me. I have before me all stages of Rhyphus punctatus Meigen and Mycetobia divergens Walker, and describe and figure them herewith. FAMILY CHARACTERS Larva.—Very slender, tapering towards extremities. Head com- plete, subconical; antennae distinct; mandibles opposed; maxillary palpi poorly developed. Thoracic segments simple, longer than broad, and, like those of abdomen, circular in transverse section; prothoracic spiracles distinct. Abdominal segments divided transversely as in Therevidae; pseudopods absent; apical segment tapered; spiracles of moderate size, terminal, surrounded by 5 short processes in Rhyphus. Pupa.—Slender. Head, between antennae, with 2 slight protuber- ances, each of which is surmounted by a weak hair; antennae curved round in front of and over upper margin of eyes, extending to bases of wings; palpi straight on apical portion and directed laterad. Thoracic respiratory organs but little elevated; fore tarsi overlying mid pair, the latter overlying hind pair, both mid and hind pairs sur- passing apices of wings. Abdomen armed with 2 transverse series of thorns on each segment; spiracles small but distinct. Imago.—The imagines of the three genera are more diverse in structure than are the genera in most families of the Nematocera, and it is possible that some future writer may separate them. A general- ization of the generic characters will be found in the synoptic key to the Nematocera on a previous page. 242 HABITS OF LARVAE The larvae of Rhyphus are found in manure, decaying vegetation, and occasionally in cesspools or bodies of stagnant or impure water; those of Mycetobia are found in wounds on trees, feeding upon the exuding sap and its attendant fungus. Rarely both genera are found together. I have found nematode parasites in the larvae of Mycetobia at Urbana, IIl. ; HABITS OF IMAGINES Both Rhyphus and Mycetobia are found commonly on tree- trunks and on windows in houses. They feed upon nectar and liquid matter. Keys To GENERA LARVAE 1. All segments conspicuously marked with dark brown; head but lit- tle shorter than prothorax; apical segment with 5 short but dis- tinct processes round the spiracular disec.............. Rhyphus. . — Only the thoracic segments conspicuously marked, the markings yel- » lowish or very pale brown; head conspicuously shorter than pro- thorax; apical segment with microscopic processes round the spi- racular dise which are invisible except under a very high-power METS 5 aire, ca eh tial ote ayaa eeheeshe ates a ya sae teeter ane Mycetobia. PUPAE 1. Spiracular opening of the prothorax rather large, cireular, distinet- ly but not greatly elevated; thorns in transverse series near pos- terior margin of each abdominal segment rather widely separated 5 ER LG She raat steers a ropes Be eine t Ne % aes LUA USS — Spiracular opening of moderate size, situated upon a conspicuous tubercle, with a ridge-like elevation extending caudad of it; thorns in transverse series near posterior margin of each abdominal seg- ment close together, generally contiguous............ Mycetobia. IMAGINES 12” Diseallicell’ot winecabsentives-:. secret ise: ce trees Mycetobia. = Diseal ‘cell of wing’ present: so 2 shinee ee ee nels sce ee eee 2 2. All branches of radius ending in margin of wing........ Rhyphus. — Second branch of radius ending in first............... Olbiogaster. RuypuHus Latreille I have but one species of this genus represented by all three stages, consequently it is unnecessary to summarize the generic characters. 243 Only four species are recorded from the United States, two of which, alternata Say and punctatus Fabricius, occur commonly in Illinois. RuypuHus PUNCTATUS Fabricius Rhagio punctatus Fabricius, Mantissa Insectorum, Vol. 2, p. 333. (1787) Larva.—Length, 9-10 mm., diameter, .75 mm, Yellowish white, with the greater portion of each segment marked with fuscous brown, the dark portion containing a number of rounded or elongate pale spots. Head larger and more tapered anteriorly than in Mycetobia, the dorsal aspect as in Figure 4, Plate XXXVI; eye-spots distinct ; anten- nae smaller than in Mycetobia; mandibles as in Figure 5, their apices blunt, without well-developed teeth, and obscured apically by long and dense hairs; maxillary palpi small; maxillae hairy; labium as in Figure 12, centrally with a deep incision. Thoracic segments sub- equal in length; prothoracic spiracles of moderate size, situated on side, about one third from posterior margin of segment. All abdom- inal segments with a distinct constriction about one fifth from the anterior margin; apical segment with a large smooth plate on ventral surface, the tip of segment with 5 short processes round margin of spiracular disc (Fig. 2). Pupa.—Length, 6-8 mm. Of the same color as the larva. Head with the same armature and general structure as Mycetobia. Thoracic respiratory organs much less elevated than in that genus, their apices not reaching nearly as far as anterior margin of antennae when seen in profile. Legs and wings as in Mycetobia, the principal difference, apart from the thoracic respiratory organs, lying in the armature of the abdominal segments, as indicated in key to genera and in Figures 8 and 9, Plate XXXVI. I have before me larvae and pupae that I obtained June 24, 1916, from horse-dung at White Heath, IIl., and similar material submitted by J. A. Hyslop, obtained at Hagerstown, Md., from cow-dung. The species is found in Europe and North America, and is usual- ly very common throughout the warmer portion.of the year. The larvae feed in decaying vegetable matter, manure, and occasionally in sewage or foul water. The imagines occur very often upon windows of houses and outbuildings, but are quite frequently found at rest upon tree-trunks. They feed upon exuding sap of trees and upon nectar of flowers. 244 MycerosiA Meigen I have before me all stages of the only described North American species of this genus. The early stages have been previously described by Johannsen and myself, and the figures given herewith are merely supplementary to these descriptions, references to which are given in the synonymy of the species. MYCETOBIA DIVERGENS Walker Mycetobia divergens Walker, Ins. Saund., Dipt., Pt. 1, p. 418. Imago. (1856) Mycetophila persicae Riley, Prairie Farmer, June 15, 1867, Vol. 35 (mn. s.,. 5), No. 19, p. 397. Imago. Mycetobia sordida Packard, Guide to the Study of Insects, p. 388. Imago. (1869) Mycetobia marginalis Adams, Kans. Uniy. Sci. Bull., Vol. 2, No. 2, p. 21. Imago. (1908) Mycetobia divergens Walker, Johannsen, Bull. 172, Maine Agr. Exper. Station, p. 223. Larva, pupa, and imago. (1910) ‘Mycetobia divergens Walker, Malloch, Bull. Ill. State Lab. Nat, Hist., Vol. 11, Art. 4, p. 321. Larva and pupa. (1915) Larva (Pl. XXXVI, Fig. 3).—Length, 11-13 mm., diameter, .60 mm. White, semitransparent, thoracic segments marked with yel- lowish brown. The principal distinguishing features of this species as compared with Rhyphus, apart from the difference in color and shape of the apical segment, mentioned in key, are the more slender build of the body and the dissimilar structure of the head. The greatest difference is apparent in the form of the labial plate and mandibles, as shown in Figure 11, the mandibles in the present species being pointed, and armed on the upper margin with several teeth, while the labium is not centrally incised. Pupa.—The principal differences between the two genera are em- phasized in the key to pupae, and a comparison of Figures 8 and 9, Plate XXXVI, will show the general build of the cephalic, thoracic, and basal abdominal regions, as well as the armature of the latter, in which there are decided differences. ‘The ventral aspect of the head, thorax, and base of abdomen is shown in Figure 6; the dorsal aspect of head and thorax in Figure 7. The larvae of this species are very commonly met with in wounds on trees from which sap is exuding. They feed upon the sap or the fungus occurring in such situations, and the pupae are found among the loose bark, especially where it is damp. The imagines behave in 245 much the same manner as do those of Mycetophilidae, hiding away in chinks in the bark of trees, and frequently feigning death when dis- turbed. They are much more active than Rhyphus and generally shun the light, whereas the latter do not appear to do so. The food con- sists of exuding sap of trees. Tribe EucrPHALA I have retained in this tribe, which is one of those proposed by Brauer, three superfamilies, removing Bibionoidea to Oligoneura. The tribe contains an assemblage of families that show a consid- erable range of variation in the structure of practically all parts of the body in the larvae, but these all possess a complete head with opposed mandibles and usually a well-developed labium. The antennae are usually well developed, consisting in Chironomidae of four to six joints, but in Mycetophiloidea, exclusive of Bolitophilidae, these organs are rudimentary, being usually very slightly elevated clear spots, contrasting sharply with the dark color of the remainder of the head. Peripneustic forms are present in Bolitophilidae, Mycetophilidae, Sciaridae, and Chironomidae, while some of the other families contain species that have rudimentary abdominal spiracles. I have decided upon the present grouping of the genera after a consider- ation of the characters of all the stages. This arrangement is quite different from that outlined by de Meijere* in a paper that appeared when my manuscript was almost completed. I am not dogmatic with regard to my arrangement of the families concerned, and it should prove interesting to students to compare the results as presented in the two papers. As this paper is primarily intended as a handbook for the ready identification of immature forms of Diptera and not as a discussion of affinities, it is deemed inadmissible to bolster the classification suggest- ed by lengthy argumentation. The proving or disproving of the sug- gested affinities is left to the future, and probably to other students. In order to locate species of the tribe it is necessary to make use of the keys to the various stages of Nematocera on a previous page. The structure and habits of the species are dealt with under the family, subfamily, or generic headings. *Zool. Jahrb., Abt. f. System. Geog. u. Biol., Vol. 40, Pt. 3-4, 1916, p. 307. 246 Superfamily Mycetophiloidea This superfamily, as at present defined, includes the following families: Bolitophilidae, Mycetophilidae, Sciaridae, Macroceridae, and Platyuridae. The first three families contain, as I believe, the most primitive larval forms known to me, but the fifth has evolved a form that to my mind shows considerable specialization, while the imagines show less specialization, in so far as the wings are concerned, than do those of © Mycetophilidae and Sciaridae. The early stages of Macroceridae are unknown to me. < SUPERFAMILY CHARACTERS Larva.—Head complete, the sclerites, ventrally, more or less dis- tinctly separated, often connected by narrow chitinized strips; mandibles opposed, toothed; antennae poorly developed except in Bolitophilidae; maxillae differing from those of other Nematocera in having their inner margins serrate; maxillary palpi developed or un- developed. Larvae peripneustic except in Platyuridae, the latter with- out distinct lateral abdominal spiracles and with protrusive anal re-° spiratory gills. Abdomen, and sometimes some or all of the thoracic segments, with locomotor spinules, or the entire body without such organs. Abdominal segments in Platyuridae with conspicuous trans- verse ridges, giving the body an annular appearance. Pupa.—Head small, sometimes retracted, bringing its anterior margin in line with anterior margin of thorax; antennae elongate, either curved over eyes or projecting in a straight line from upper margin of head to base of wing or slightly beyond that point. Thoracic respiratory organs sessile, very rarely elevated. Wings more or less closely adherent to body; legs long, straight, extending much beyond apices of wings. Abdomen with 6 pairs of spiracles and without dis- tinct armature on dorsum; apical segment sometimes with 4 short spines. Imago.—The imagines of this superfamily have the radial vein of wings with 2 or 3 branches. The species which have 2 branches only, lack the medio-cubital cross-vein. One of the subfamilies which I have placed in Mycetophilidae has the radius with 3 branches, but the second joins the first and forms a more or less elongated closed cell, and the medio-cubital cross-vein is absent. The antennae are filiform, very rarely thickened, and occasionally remarkably elongated and slender; the proboscis is usually short and fleshy, rarely elongate (Asindulum and Eugnoriste). For synoptic characters see key to imagines of Nematocera. 247 Family BOLITOPHILIDAE FAMILY CHARACTERS Larva.—B olitophila larvae differ from the larvae of Mycetophili- dae in having 2-jointed, well-developed antennae, the head subquad- rate, and the median dorsal sclerite truncated apically, its sides on posterior half being little or not at all convergent posteriorly. From the larvae of Platyuridae it differs in having well-developed abdom- inal spiracles and the abdomen without conspicuous transverse ele- vated ridges. The pupa is unknown to me. Imago.—Differs from Mycetophilidae in having the radius with 3 branches and in the presence of the medio-cubital cross-vein, from Platyuridae in its distinct medio-cubital vein, and from other families as indicated under the heading “Notes on Family”. The species are generally more fragile than Platyuridae and allied families. HABITS OF LARVAE The larvae are mycetophagous, feeding upon fungi growing upon trees, under logs, or in dense woods or in fields. HABITS OF IMAGINES The imagines are very rare in North America. They are usually found in woods, and particularly along the sides of ditches or streams in wooded localities, from the grass-grown overhanging banks of which they may often be beaten in spring and fall. They hibernate in these situations in Europe, and very probably in this country also. NOTES ON FAMILY There are but two genera in North America that belong to this family, Bolitophila and Palaeoplatyura. Hesperinus, which has been placed here, possesses only 12 antennal joints and belongs to the Bibi- onidae. Johannsen expressed an opinion to this effect in his paper on the Mycetophilidae*. The subfamily Mycetobiinae of Johannsen’s paper is also, I am certain, composed of genera that are not closely allied. Palaeoplatyura very probably belongs to Bolitophilidae, where I have placed it, while Ditomyia and Symmerus should form a fam- ily by themselves. Palaeoplatyura is more closely related to Bolitoph- *The Fungus-gnats of North America, Pt. IT, p. 222. (1910) 248 ila than to Mycetobia, as is evidenced by the complete media, and by the presence of the subcostal cross-vein in P. johnsoni. Ditomyia and Symmerus both lack the basal part of media and the subcostal cross-vein, while, in addition, the subcostal vein is incomplete. Mycetobia belongs to Rhyphidae. There are two North American species of Palacoplatyura, and four of Bolitophila,—two of which, cinerea and hybrida, occur also in Europe. Key To GENERA 1. Medio-cubital cross-vein proximad of radio-medial, so that the 2 cells separated by basal portion of media are very unequal in . lenothl: 24/2 sh Gis, SUAS Eee Se ae es Bolitophila. — Medio-eubital cross-vein almost in vertical line with radio-medial, so that the 2 cells separated by basal portion of media are almost equalhiny lengths aanen crise iers dabidsile Pale seeks Palaeoplatyura. Key To IMAGINES oF BoLITOPHILA MEIGEN 1. Fork of third vein ends in first branch of radius (Europe; N. Y.) BR EEE RST eon bts aa OANA chien lbs cinerea Meigen*.. — Fork of third vein ends in costa..................- fare. sycnel ere eaeie 2 2. Anterior branch of cubitus discontinued some distance from base Gidaho\;NiNHe) cence Settee ste disjuncta Loew. — Anterior branch of ecubitus complete Heian 'e quae eaikens ne orem 3 3. Subcostal vein ends in costa at a point above or beyond the base of radial sector—third vein (N. H.; Ind.; B. C.)..hybrida Meigen. — Subcostal vein ends in costa at a point much proximad of base of Tadiallsector: (Ns wElewINGaaNe) meer eee eerie montana Coquillett. Key To IMAGINES OF PALAEOPLATYURA MEUNIER 1. Wings unmarked; subcostal cross-vein absent (Wash.)........... Shade lalla auboaiSratapanthers arn eal eet epee aldricht Johannsen. — Wings with grayish or fuscous markings; subcostal cross-vein pres- ent 4GVite)) cc: -cotteeaceo + ee ee ACE: johnson’ Johannsen. *The larva of Bolitophila cinerea has been figured and briefly described by Dr. Felt in the Twenty-ninth Report of the New York State Entomologist, p. 67. (1915) Family MYCETOPHILIDAE The limits of this family are somewhat doubtful, and the most recent papers on it seem to me to include a rather heterogeneous as- semblage of genera that require considerable family subdivision. ‘The 249 importance of certain structural details of the imagines is not suf- ficiently realized as yet, and as we gradually accumulate data upon the larval and pupal stages I am confident that certain groups at present considered as genera in the family will be elevated to subfamily, and some even to family, rank. I have taken upon myself the responsi- bility of separating some of the so-called subfamilies from Myceto- philidae—a step which I consider justified because of distinctions which are evident in the adult insects, and also in the known !arvae and pupae. FAMILY CHARACTERS Larva.—Head complete, not very heavily chitinized, usually con- spicuously different from the remainder of body in color; antennae usually short, appearing in many genera as pale rounded areas on each side of head near anterior margin; mandibles toothed; maxillae well developed, their inner surfaces usually conspicuously dentate; max- illary palpi developed or very slightly so; labium not in the form of a flat plate; median dorsal sclerite of head tapering to a point posteriorly. Ventral surface of thoracic and abdominal segments sometimes with a transverse band of black locomotor spinules, which are occasionally very conspicuous; prothoracic and first 7 ab- dominal segments each with lateral spiracles; apex of abdomen sim- ple; anal spiracles terminal. Pupa.—Head unarmed; antennae curving well over upper mar- gins of eyes, forming a semicircle and ending about middle of wings along their costal margins. Thorax conspicuously elevated, the an- terior margin almost vertical, the dorsum appearing in lateral view almost globose; spiracles not elevated; legs elongated ; entire fore legs visible; mid coxae visible only in part; apices of all legs extending bevond apices of wings, those of the hind pair sometimes reaching apex of abdomen. Abdomen unarmed; 7 pairs of spiracles present, the basal pair usually hidden by wings. Imago.—As limited in this paper this family contains only those genera that belong to the following subfamilies of Johannsen’s paper on Mycetophilidae: Diadocidiinae, Sciophilinae, and. Mycetophilinae. I consider that these three groups really constitute separate families, but in the absence of larval and pupal material as criteria I prefer to leave matters at present as they are, hoping at some future time to elucidate further their relation, or that some other student of the order may And time to do so. 250 HABITS OF LARVAE As the popular name, fungus-gnat, indicates, the larvae feed up- on fungi in the great majority of cases. The species of fungi they attack and the situation in which the larvae are found differ very con- siderably. Many species feed upon Agaricus and allied genera in open situations ; some feed upon Polyporus and other fungi growing upon living or dead trees; while others feed upon minute fungoid growths upon the under surfaces of fallen trees, rails, or boards upon the . ground, and a few appear to live entirely upon vegetable matter in an advanced stage of decay. Nearly all the larvae spin webs in the gal- leries they make in their food; in the case of species that live exter- _ nally upon fungi the web is slimy, rather loose, and irregular. I have paid particular attention to some species I have reared, and find that the larvae of this last group do not pass over the threads but through them, as in a tube, the body being enclosed except anteriorly. The threads are slimy in nature, and the presence of the larvae may he de- tected by the glistening surface of the fungus, whick appears as if a slug had crawled over it. The larvae, as far as I have observed, spin a cocoon of a more or less compact nature to pupate in. In the case of Leia the pupa is simply suspended by means of a number of loose threads which keep it from the surface of the fungus or other matter in which it is found, and very probably safeguard it to some extent, as mites seem unable to cross the threads. HABITS OF IMAGINES The imagines are found in a variety of situations, but most com- monly in damp and rather dark places, especially where there is fun- goid growth. Damp basements, old outhouses, and hotbeds, usually vield many species. In woods the greatest number may be obtained by sweeping amongst undergrowth in the most shady spots, though a number of species may be found on tree-trunks, where they run with surprising speed. Several species occur upon flowers, but the major- ity of them only in the late afternoon. Many species will on occasion feign death, but spring to life suddenly when touched. I have found specimens still enclosed within their loose silken cocoon when collect- ing under bark in spring. When touched the insects make a hurried exit only to feign death after progressing a few inches, and by means of alternate rushes and pauses they soon succeed in burying them- selves under any loose detritus that is convenient. 251 Krys TO SUBFAMILIES LARVAE 1. Head usually deep black, only the antennal sockets and some small round spots pale; maxillary palpi not protruded.............. BPMs iayeus vai euecejeu ae) sip abayianavaparekasels dev eyous 3) atsy dusnoieve a's MYCETOPHILINAE. — Head pale, antennal sockets surrounded by a black band; maxillary palpi sometimes protruded (Sciophila)........... ScIOPHILINAE. PUPAE 1. Thoracic and abdominal respiratory organs sessile; slender species; legs and wings not closely fused together and to thorax......... BRS TER cots Ae apie ue IR at ate o Recea ie eveials, Siew euros. MYCETOPHILINAE. — Thoracic and abdominal respiratory organs elevated; robust spe- cies; legs and wings closely fused to each other and to thorax.... Ae ERO OO TOES ID OO OI OCC I *,...28...+.+SCIOPHILINAE. IMAGINES 1. Medio-eubital cross-vein present ; radius with 2 branches.......... OP erecta ends = oy sie toatl etader sh aperein as oa orale Staie cual DIADOCIDIINAE. SE VEHIO-CUDIialy CrOSS-VEIM, ADSCNG. c. si ccc dc cou coe see cee sa cise 2 Radius with 3 branches, the intermediate one connecting first and third usually near base of latter and forming a subquadrate or OI OTIC Mea ent tes cake, opstaye hatte “enerers (erst obauslciege t blehsteer se SCIOPHILINAE. Pacis) with 2) DYADCNES!): 5... 000.0002e0000e 0c ee MYCETOPHILINAF. ) Subfamily MYCETOPHILINAE I have obtained the larvae and pupae of representatives of two genera of this subfamily. The larvae of these genera differ very markedly from each other though the pupae are very similar. SUBFAMILY CHARACTERS Larva.—Head glossy black; antennae sessile; a conspicuous pellucid spot on each side of head below antennae; dorsal sclerite of head gradually tapered from before middle to posterfur margin; max- illary palpi sessile, in the form of a rounded pellucid spot; entire inner margin of maxillae serrated; mandibles with 3 or more strong apical teeth, or with a continuous series of short teeth along one margin. Prothoracic and abdominal spiracles present. Locomotor organs in- distinguishable or well developed, consisting, when present, of 2 trans- verse series of spinules on ventral segments. 252 Pupa.—More slender than pupa of Sciophilinae, and with legs and wings less closely adherent to each other and to thorax. The thoracic respiratory organs and the lateral abdominal spiracles are sessile; in Leia the basal abdominal segment has the spiracles rudimentary. The legs of the two genera are of different lengths. HABITS OF LARVAE The larvae of most genera of the subfamily are fungivorous, some feeding internally and some externally. ‘Those that feed in the stems or other parts of fungi line their burrows with a slimy sub- stance, while those that feed externally move inside of tube-like slimy threads. HABITS OF IMAGINES The imagines feed upon nectar and exuding sap of trees. They very frequently feign death when disturbed, and at other times squeeze themselves into very small cracks or openings in an effort to escape capture or injury. Krys To GENERA 1. Locomotor spinules indistinguishable or very weak........... Leia. — Locomotor spinules strong, black, forming a conspicuous transverse band on each ventral abdominal segment............. Exechia*. PUPAE 1. Legs quite dissimilar in length, apices of fore tarsi extending to base of fifth segment of abdomen, those of mid pair to apex of sixth, and those of hind pair to base ofvelehthteeas ace .... beta. — Legs of nearly uniform length, terminating at apex of abdomen in a slightly concave transverse line..................+0- Exechia. Lea Meigen This genus contains a number of common and widely distributed species, which are usually conspicuously marked with black on a red- dish yellow ground-color, and often have distinctly marked wings. GENERIC CHARACTERS Larva.—Head glossy black, much longer than broad, the posterior margin not excised; antennae very short and fleshy; pellucid spot be- *Some species of Mycetophila have locomotor abdominal spinules similar to those of Exechia, as described above. Osten’ Sacken figures the lateral cephalic sclerites of Mycetophila signata with rounded productions of their inner posterior extremities. 253 low antennae distinct; median dorsal sclerite pointed posteriorly. Thorax and abdomen without locomotor spinules; thoracic and ab- dominal spiracles distinct, the openings blackened. Pupa.—Anterior margin of thorax declivitous; thoracic spiracles not elevated; antennae elongate, curved well over eye and ending about middle of wing; fore, mid, and hind legs ending at different distances from apices of wings; abdomen without noticeable armature. HABITS OF LARVAE The larva lives in a loose slimy web on damp rotten wood or on fungus, and the pupa is found suspended in the threads. The larvae are very active, moving within the slimy tubular thread, either for- ward or backward, with great facility, and in their behavior resem- bling. some tortricid larvae of the Lepidoptera. HABITS OF IMAGINES The imagines closely resemble those of Mycetophila and are found in the same situations—sometimes on flowers, on windows, or under logs, and not uncommonly at lights. I have found L. oblectabilis in hundreds on the walls and windows of the Natural History Building here in July and August. LEIA OBLECTABILIS Loew Glaphyroptera oblectabilis Loew, Berl. Ent. Zeitschr., 1869, p. 146. Larva.—Length, 11-13 mm. White, semitransparent; head glos- sy black. Median dorsal sclerite of head tapering gradually from before middle, ending in an acute point at posterior margin (Pl. XXXVII, Fig. 1); antennae not elevated, represented by rounded, pale, mem- branous areas; pellucid spot below antennae large and rounded; mandibles with 3 large teeth and 2 small ones on outer margin, and 3 or 4 on inner surface (Pl. XXXVII, Fig. 10) ; maxillae serrate on inner margin, the palpi not well-developed (Fig. 13) ; ventral surface of head as in Figure 14 of plate mentioned, the posterior excision cordiform; hypopharynx as in Figure 8. Prothoracic and abdominal spiracles small, the latter especially so. Abdomen glabrous. no loco- motor organs distinguishable. Pupa (Pl. XXXVII, Fig. 5).—Length, 5-6.5 mm. White, be- coming darker and showing the markings of the imago as the latter nears emergence. 254 Head without protuberances; antennae extending beyond base of wing; palpi straight, directed laterad; wings extending slightly beyond base of fourth abdominal segment; fore tarsi extending to base of fifth, mid pair to base of seventh, hind pair to base of eighth. Ab- domen glabrous; 6 pairs of well-developed lateral spiracles present, basal pair rudimentary. Described from a number of specimens obtained by myself at White Heath, Savoy, and Urbana, IIl., in June, July, and September, 1915-16. Execuia Winnertz As I have but one species of this genus represented by other than the imaginal stage, the generalization for the larval and pupal stages may not apply to all species of the genus. GENERIC CHARACTERS Larva.—Head not much longer than broad, posterior margin with a central and medio-lateral excision on dorsum; central plate tapered gradually from before middle, ending in a rounded point .at posterior margin; antennae sessile; pellucid spot below antennae distinct; mandibles rounded, with numerous short teeth; maxillae normal, their palpi larger than those of Leia; ventral excision as in that genus. Body with locomotor organs on venter, each consisting of 2 transverse series of black spines; spiracles conspicuous, the prothoracic pair slightly elevated and with 4 openings. Pupa.—Similar to the pupa of Leta, but differing in the length of the legs. HABITS OF LARVAE The larvae are fungivorous, feeding usually in the stems of mush- rooms. ‘They commonly line their burrows in the stems with a slimy fluid similar to that excreted by Leia. Pupation takes place in the burrows. The species which I have reared, or attempted to rear, are often killed by a hymenopterous parasite when on the point of pupation. HABITS OF IMAGINES The species frequent woods, especially the denser parts, and may often be taken in great numbers about fungi. They very often occur 255 on the windows of houses, particularly in the evening, and they are readily attracted to lights. In Britain many species of this and allied genera occur during winter in clumps of grasses and ferns overhanging streams and ditches, and this fact seems to indicate that they hibernate as adults. EXECHIA NATIVA Johannsen Exechia natiwa Johannsen, Bull. 200 Maine Agr. Exper. Station, p. 70. (1912) Larva (Pl. XXXVII, Fig. 3).—Length, 8-9 mm. White, head and locomotor spinules black. Head as in Figure 7, Plate XXXVII; mandibles different from those of Leia in having 9 sharp teeth distributed along their entire out- er margin (Fig. 6); maxillary palpi much longer than in Leia (Fig. 9); hypopharynx as in Figure 11. Thoracic spiracles each with 4 slit-like openings (Fig. 4) ; abdominal pairs smaller than the thoracic. Locomotor spinules arranged as in Figure 2, Plate XXXVII, the apices of the spinules in the anterior and posterior series directed respectively cephalad and caudad. Pupa (Pl. XXXVII, Fig. 12).—Length, 4-6 mm. Color at first like that of larva, but later becoming darker, and just before the emergence of the adult the color of the latter is clearly discernible through the pupal skin. Head unarmed, slightly more retracted than in Leia; antennae ex- tending beyond middle of wings; palpi directed straight laterad. Thoracic respiratory organs sessile; wings extending to middle of fourth abdominal segment; legs extending to apex of abdomen, end- ing in an almost straight transverse line. Abdomen without arma- ture; spiracles slightly elevated. Described from specimens I collected from the stems of a species of Agaricus in the forestry of the University of Illinois, at Urbana, in September, 1915. The effect of parasitism upon the pupa is shown in Figure 15, Plate XXXVII, the larval skin having been shed but the formation of the pupa prevented. Subfamily SCIOPHILINAE This subfamily is unknown to me in the immature stages except by the larval exuvium and the pupae of one species and from pub- lished descriptions of the larvae of others. The tracheal system of Sciophila, as described by several writers, corresponds with that. of Leia and Exechia, as well as with other described genera of Myceto-~ philinae, in having lateral openings on abdominal segments 1-7. There is however an illustrated published description by Schmitz of the larva of a European species of Polylepta that shows no abdominal spiracles. I have not the larva of Polylepta, which appears to form a connecting link between this subfamily and Platyuridae. Osten Sacken states that the abdominal spiracles in the species of Sciophila known to him were very small, which would seem to indicate a step towards their ultimate elimination as functional organs. Dufour’s description and figures of a species of the same genus represent the spiracles as large, the thoracic pair bifid. I have only an exuvium, and give no data on this point. CHARACTERS OF SUBFAMILY Larva.—Head elongate; maxillary palpi well developed in Sci- uphila only; cephalic sclerites contiguous medianly on anterior half of their ventral surface, but widely separated on the posterior half. Body very slender; spiracles present on abdominal segments in Sciophila, absent in Polylepta. Pupa.—Stout. Head without protuberances; palpi curved for- ward on their apical halves; antennae curved over upper margin of eyes, extending to middle of wing. Thorax declivitous anteriorly; respiratory organs slightly elevated; wings extending tc apex of third abdominal segment; legs parallel, the tips of tarsi reaching to apex cf seventh abdominal segment. Abdominal spiracles slightly elevated, absent on first segment in species before me. Imago.—Distinguished from Mycetophilinae by the furcate third vein, the anterior branch leaving the posterior at right angles and joining the second vein in similar manner, thus forming a subquad- rate or elongate closed cell. PotyLerta Winnertz The larva of one species of this genus, which occurs in caves in Europe, has been described by Schmitz*. This species, P. leptegaster, has been recorded from North America, and a summary of the de- scription is given herewith as the original publication is uot generally available in this country. ; As indicated previously, the larva has no lateral abdominal spira- cles, which is at variance with the rule in Mvcetophilidae. *Naturhist. Genootschap in Limburg, Jaarboek, 1912, 4th Note. 257 POLYLEPTA LEPTOGASTER Winnertz Polylepta leptogaster Winnertz, Verh. zool.-bot. Ges., Vol, 13, p. 746. Imago. (1863) Larva.—tLength, 10 mm. Body worm-like, long and slender, in the middle cylindrical, tapering towards extremities. Functional spiracles present on prothorax only, the tracheal trunks confined to the first 2 thoracic segments, terminating on each side at posterior mar- gin in 2 closed functionless spiracles. Head elongate (Pl. XX XVIII, Fig. 3) ; antennal sockets surrounded by a chitinized dark band, the antennae rudimentary; maxillary palpi not protruded as figured by Osten Sacken for Sciophila, their apices extending very slightly be- yond apices of the serrated maxillae; mandible with 5 teeth, the upper one strong, the others becoming progressively weaker to lower one (Pl. XXXVII, Fig. 16) ; median opening in posterior half of ventral surface of head cordiform. Abdominal locomotor organs very weak. Pupa.—Undescribed. This species has been recorded from New Hampshire and Indiana, Schmitz’s specimens were obtained in a cave in Europe. Johannsen records 4 species of the genus from North America. MYcoMA BREVIVITTATA Coquillett Sciophila brevivittata Coquillett, Jour. N. Y. Ent. Soe., Vol. 13, 1905, p. 67. Mycoma brevivittata (Coquillett) Johannsen, Bull. 180, Maine Agr. Exper. Sta- tion, p. 176. (1910) Larva (exuvium).—Head as in Figures 1 and 4, Plate XX XVIII; maxillary palpi short, not surpassing the apices of maxillae; antennae not protruded, the antennal socket surrounded by a black band; mandibles with a double series of teeth, which are very unequal in size (Pl. XXXVII, Fig. 17); median dorsal sclerite of head tapering to a point posteriorly. Tracheal trunks large; prothoracic spiracles dis- tinct; no other spiracles discernible in specimen, but they are rarely visible in exuvia though they may be present in the larva; locomotor spinules not distinguishable. Pupa (Pl. XXXVI, Fig. 18).—Length, 4-5 mm. Brown, slight- ly shining; enclosed in a silken web. Stout; anterior margin of thorax vertical, head not extending to anterior margin of thorax; antennae curved over upper margin of eyes and extending to middle of wing, their bases rounded in profile; palpi not extending to upper eye-margin. Thoracic respiratory organs elevated ; surface of thorax with short sparse setulae; wings, antennae, 258 and legs closely fused to thorax; wings extending to apex of third” segment or slightly beyond it; legs extending to apex of seventh seg- ment, their apices forming a slightly concave transverse line. Ab- domen with numerous microscopic dorsal setulae; spiracles of first segment obsolete, those on segments 2—7 elevated; metanotum cen- trally concave anteriorly, so that its length at center is about half that of first abdominal segment, while laterally it is as long as the latter; second segment longer than any of the others; seventh about half as long as sixth; eighth and ninth segments combined equal in length to sixth, The foregoing descriptions were made from a larval exuvium and pupae, the species being obtained by me in the Augerville woods near Urbana, Ill., June 23, 1916. The larvae were feeding on a fungus growing upon the under side of a log lying upon the ground. The principal differences between this species and Polylepta lep- togaster, exclusive of any that may exist in the respiratory system, lie in the structure of the mandibles and of the maxillae, and in the ab- sence of locomotor spinules. Schmitz figures the Soule dorsum as entire in Polylepta, which may be an error. Family SCIARIDAE The members of this family have until recently been classed as a2 subfamily of Mycetophilidae, but in this paper and in some papers by other authors they are accorded family rank. There is a striking uniformity of structure in the imagines of Sciara—the genus that con- tains by far the largest number of the included species—and in the larvae known to me there is also a striking similarity in appearance and structure. I have reared but few species, and my generalizations are based upon these. FAMILY CHARACTERS Larva.—Head like that of Mycetophilinae, differing principally in having 2 narrow bands of chitin connecting the lateral sclerites on their ventral surface (Pl. XXXVIII, Fig. 2), in having the median dorsal sclerite distinctly and often rather abruptly constricted at or slightly beyond middle (Pl. XX XVIII, Figs. 6, 9), and in the absence of the clear spot below antennae. ‘The martibles are almost quad- rate in outline, have 3 large apical teeth, and usually 2 or 3 smaller ones at inner angle of apex (Pl. XXXVIII, Fig. 14). The general shape of the head in species known to me is subquadrate (PI. 259 XXXVIII, Fig. 6). In other respects the larvae closely resemble those of Leia, the locomotor organs when present being inconspicuous and the abdominal spiracles black and easily distinguished. Pupa (Pl. XXXVIII, Figs. 5, 7).—General appearance similar to that of pupae of Mycetophilinae, but differing noticeably in having the thorax much less swollen and not declivitous anteriorly, the an- tennae much longer, frequently extending to apices of wings, and the fore, mid, and hind legs of conspicuously different lengths, and no- ticeably shorter than in Mycetophilidae. The abdomen is sometimes turnished with short setulose hairs and has 6 pairs of exposed spir- acles as have Leia and allied genera, the basal(seventh) pair very small and discoverable only by careful examination and partial dissection of base of abdomen. The legs in many species are very much shorter than in Sciara prolifica, which is the species figured, the hind pair sometimes reaching only to apex of fourth segment. The abdomen also lacks the short setulae that are present in prolifica. HABITS OF LARVAE The larvae are essentially scavengers, feeding upon decaying vege- table matter, and manure, but some species do considerable damage to cultivated mushrooms, and under natural conditions feed on fungi. Occasionally i in early spring some species appear in immense numbers. in plant- -propagating houses, having been introduced in leaf-mold in very late fall or in winter while in the egg or larval stage. Some species, usually when full-grown, have a peculiar habit of leaving the place where they have fed and traveling on the surface of the ground in a rope-like aggregation, which may attain a diameter varying from an inch to three inches and a length of eighteen inches to five feet and contain several thousand larvae. Some European authors give the size of these ropes as three to four inches wide and twelve to fourteen feet long. This habit has long been known in Europe, and has given the larva the names “rope-worm’’, “‘snake- worm”, and “army-worm”. A few records of this habit in America have appeared, the last I know of being in my paper in the preceding volume of this bulletin.* This office has on file records of these larvae feeding upon dead white-grubs that were killed by fungi or bacteria. Some species form a slight shiny tunnel-way in which they live, but it is difficult to detect it in most cases. *Vol. 11, Art. IV, p. 320. (1915) 260 HABITS OF IMAGINES The imagines have much the same habits as Mycetophilidae, but I have rarely seen them feign death as do the imagines of Cordyla and Mycetophila. Eugnoriste, which has a very long proboscis, is com- monly found on flowers of Erigeron and similar plants. Most species of Sciara are common on plants and assumably feed on nectar. Family MACROCERIDAE I have not found the early stages of any species of this family, and consequently can not include it in my keys to the larvae and pu- pae. The species are generally rare in North America, but in Europe several occur rather commonly, especially under overhanging banks of streams in or near woods. In early spring they may be beaten from such banks, where grass or ferns overhang their edges, and from the fact that I have taken some species very late in the fall and again early in the spring I assume that they hibernate in the adult stage. There is but one genus in the family, twelve species of which are listed by Johannsen. Three species are known to occur in Illinois. Family PLATYURIDAE FAMILY CHARACTERS Larva.—Head subquadrate, the labrum slightly protruded; an- tennae very short; mandibles serrate; maxillary palpi sessile; maxillae serrate ; median dorsal sclerite of head not tapering to a point poste- riorly. Thorax and abdomen without distinguishable spiracles, the latter with a pair of protrusive blood-gills on apical segment; all seg- ments with a number of flat transverse ridges separated by rather deep and very narrow depressions; entire body slightly flattened and with a narrow lateral extension each side which is crossed by ridges as is the dorsum. Pupa.—Head more protruded than in Mycetophilidae; antennae broad, projecting upward and backward in a straight line, ending near base of wing. Abdominal spiracles elevated; legs long, the apices of hind pair extending to apex of abdomen. HABITS OF LARVAE. The larvae live in slimy webs on fungi, usually on the under sur- face of such as grow upon fallen or decaying timber. They move 261 freely, usually within the tube-like threads, and frequently turn com- pletely around in these, moving along with a gliding effect. They do not move very rapidly when taken from the webs, and are very fragile. Before pupation they spin an elongate cocoon, which is round- ed at each end and consists of rather coarse outer threads and a com- plete inner gelatinous envelope. To the surface of this inner cover- ing, threads leading from the body are attached, these serving as a means of suspension for the pupa. How the larval skin can possibly be shed without detaching these threads I can not explain, but it is done. ‘The cocoon is itself suspended in a mass of rather loose threads and forms a very pretty object when bedecked with tiny drops of moisture, as it usually is .in the damp situations where the species occur, All the examples that I removed from the cocoons died in the pupal stage—whether because of handling or from other causes I do not know. HABITS OF IMAGINES The imagines of this family are taken more frequently upon flow- ers than are those of Mycetophilidae, and they are not uncommon in shady places in woods and amongst long grass on railroad embank- ments, especially where old railroad ties are lying. CEROoPLATUS Bosc I have obtained the larvae of two species which I believe belong to this genus and also the pupa of one, but unfortunately failed to rear the species to maturity. The characters possessed by the larvae are summarized herewith. The larva and pupa of a European species (sesioides Wahlberg) are phosphorescent. GENERIC CHARACTERS Larva.—Semitransparent, white, variously marked with purple. Head as in Figures 10, 11, and 15, Plate XX XVIII; mandibles and maxillae as in Figures 12 and 8. Body slightly flattened dorso-ven- trally, the lateral margins slightly produced, somewhat bead-like. Thoracic markings consisting of an irregular longitudinal stripe along sides mesad of the lateral production, and usually a less clearly de- fined narrow posterior band along the hind margin of each segment. Abdominal segments with a dark band on each of the ele- vated transverse ridges on each segment, the dark color ceasing 262 a short distance from the lateral production. In one species the bands are almost uniform in color, but in the other there is a darker spot on each extremity of the posterior band, and there are 5 slight but ap- preciable interruptions in the dark stripes, giving the dorsum the ap- pearance of having 6 dark longitudinal stripes. The species which has the uniform transverse dorsal abdominal stripes has 5 transverse dark stripes on the ventral surface of each segment, the penultimate one of each series very narrow; the other species has 4 such transverse stripes, and in addition a distinct median longitudinal stripe. The apical segment in both species is as in Figure 13; the lateral pointed blood-gills are retractile. Pupa (Pl. XXXVIII, Fig. 16).—Entire body without armature, the skin very thin. Antennae much flattened, their anterior margin produced beyond the anterior margin of thorax. Thoracic respiratory organs sessile; scutellum protuberant; anterior margin of thorax sloping; wings ex- tending to apex of third segment of abdomen; fore tarsi extending to apex of seventh segment, mid pair to apex of abdomen, hind pair reaching slightly beyond apex. Abdomen unarmed; seven pairs of spiracles present. The foregoing descriptions are based upon examples obtained by the writer at White Heath, Ill, June 24-and 25, 1916. I did not ob- serve indications of phosphorescence in the larval and pupal stages, but made no effort to determine whether it existed, owing to my fail- re to note the European record until too late to verify it. Principat Papers ON NortH AMERICAN MYCETOPHILOIDEA: Johannsen, O. A. 709=4125) ihe ee gnats of North America. Parts 1-4. Bull. Maine Agr. Exper. Station, Nos. 172, 180, 196, 200. (Includes all families in my superfamily Mycetophiloidea under Myceto- philidae. ) Osten Sacken, C. R. 62. Characters of the larvae of Mycetophilidae. Proce. Ent. Soe. Phila., 1: 151-172. (Ineludes all the families of my Mycetoph- iloidea, and gives references to previous literature on life histories of the species. Sehmitz, H. ; 12. Biologisch-anatomische Untersuchungen an _ einer héhlen- bewohnenden Mycetophilidenlarve, Polylepta leptogaster Winn. Natuurhist. Genootschap in Limburg Jaarboek, 1912, 4th Note. (This species occurs in the United States.) 263 Superfamily Culicoidea This superfamily includes the following families according to the present arrangement: Psychodidae, Blepharoceridae, Culicidae, and Dixidae. ‘The last family has been considered’ by some writers as a subfamily of Culicidae. There are, however, very marked differences between the corresponding stages of Culicidae and Dixidae which I believe warrant their recognition as distinct families. SUPERFAMILY CHARACTERS Larva.—All the larvae of the group make primary or exclusive use of the anal spiracular appendages for respiration, Culicidae mak- ing exclusive use of them except in a very few cases. The larvae of this family are distinguished from those of any allied family by the fusion and very noticeable expansion of the thoracic segments. Many larvae of the subfamily Corethrinae (Culicidae) are remarkably specialized in having air-sacs in the thorax and near apex of abdomen, which show as blackish spots, and are without the elongate anal re- spiratory tubes of the normal forms of the Culicinae. These larvae are sometimes found at great depth in lakes, under anaerobic con- ditions. The larvae of Blepharoceridae have the thoracic and first and second abdominal segments fused and the head poorly differ- entiated. The lateral abdominal spiracles in this family are not func- tional. Some Psychodidae have larvae that superficially resemble those of Blepharoceridae in general form, even having median ventral sucker-like discs on abdomen as that family has; but the thoracic segments are not so closely fused, the head is well differ- entiated, and the apical segment has a more or less elongated respira- tory tube instead of its being rounded. The larvae of Dixidae in general appearance resemble those of Chironomidae, but they differ from the latter in having pseudopod-like protuberances on dorsum of basal two abdominal segments, and the head differs greatly from that of Chironomidae. These characters, in my opinion, taken in conjunc- tion with those of the wing of the adult, associate this family more closely with the Culicidae than with the Chironomidae. Pupa.—The thoracic respiratory organs are elongated in all fami- lies of Culicoidea. The pupae of Culicidae and Dixidae have the legs recurved against the ventral surface of the base of the abdomen so that they scarcely protrude beyond the apices of the wings. The legs in Psychodidae and Blepharoceridae are straight, but do not extend beyond apices of wings, or, at most, but slightly beyond. For other 264 differentiating characters see key to pupae of Nematocera and descrip- ~ tions of families. Imago.—Mouth parts sometimes fitted for piercing, rarely abort- ed; palpi sometimes remarkably long; antennae from 9- to 15-jointed, often with long plumes or with whorls of hairs; ocelli absent or pres- ent. Thorax without complete, well-defined suture. Wings without discal cell; surface often haired or scaled; costa, in all except Blepharoceridae, encircling wing, in the latter the field of wing has numerous longitudinal and transverse creases which give it the appear- ance of having a secondary venation. Legs very slender except in Psychodidae; in the latter’and in most Culicidae, with conspicuous hairs or scales. Family PSYCHODIDAE FAMILY CHARACTERS Larva.—Head complete; antennae protuberant; mandibles op- posed, toothed, sometimes with long, fringed outer processes; labium usually serrate on anterior margin. Prothorax with distinct spiracles, sometimes protuberant; thoracic and first abdominal segments with a slight central transverse constriction, giving them a biannulate appear- ance, remaining abdominal segments, except the apical one, triannu- late; some of the abdominal segments usually with a chitinized dorsal plate upon each of the annuli; in some cases all the segments of thorax and abdomen have such plates, some of those on thorax being inter- rupted longitudinally in center to facilitate the rupturing of the skin for the exclusion of the pupa; apical abdominal segment usually more or less elongated, particularly in the species without or with very few dorsal plates, in the form of a tapering tube, chitinized, the pair of tracheal spiracles opening close together at its apex, generally with 4 protuberances which are fringed with soft hairs; surface of body with moderately long bristly hairs, variously arranged in the different spe- cies. Pupa.—Prothoracic spiracles elevated, stalk-like; head parts, legs, and wings distinct, closely adherent to body; fore tarsi overlying mid pair, the latter overlying hind pair; apices of hind legs not projecting beyond apices of wings. Dorsal appearance of body in Maurina oval in outline, without a distinct break at base of abdomen; the dorso- ventral elevation very slight, so that the pupa appears somewhat in the form of an oval scale (onisciform) without projecting spines or bristles on dorsum. In Pericoma and Psychoda the pupa is much like that of a small tipulid, but the legs are very much shorter and the wings are differently shaped. 265 Imago.—Wings broad and short, generally oval in outline, with long and dense surface hairs; entire body and legs with long hairs; antennae with pedunculate joints, each joint with a whorl of hairs, joints 12 to 16 in number; palpi 4-jointed. HABITS OF LARVAE The larvae of Psychoda are found in cow dung, decaying vegetable matter, exuding sap on tree-trunks, fungi, and in putrid water; those of Pericoma are found in shallow slow-flowing water or in tree-holes ; Maurina has only been recorded from situations where the water had a rather swift flow, and it is evidently adapted to this sort of habitat by the presence of suckers on the ventral surface of the abdomen. The food of the larvae consists of algae and decaying vegetable matter. HABITS OF IMAGINES The imagines may usually be found in large numbers in close proximity to the larval pabulum, and are very common on windows in outhouses or in houses that have damp cellars, or where there are cesspools or cisterns. Rather dark, damp situations are particularly favorable to the species in any stage. ‘The flies may be found in great numbers at lights at night. Many species of Pericoma are found upon tree-trunks in the daytime. The food of the imago consists of nectar or fluid matter in the gen- era Pericoma and Psychoda, but the species of Phlebotomus are blood- suckers, feeding upon the blood of various reptiles, amphibians, and mammals—including man. Some species act as vectors of diseases of man, papataci fever and verruga being transmitted by species of Phlebotomus. Taylor has described a species from Australia, under the name Pericoma townsvillensis*, which he records as a_ blood- sucker. It is not possible to decide as to the generic status of the species, but his figure shows it to be either a Psychoda or a Phleboto- mus—probably it is the latter. Keys TO GENERA LARVAE 1. Ventral abdominal segments with median sucker-like disc; thoracic segments with larger chitinized plates than the following abdomi- MAN SEMEN LG co o.s)2 0 s\1018 0) ) 0101 Maurina (Pericoma) californiensis. *Bull. Ent. Research, Vol. 1, Pt. 3, 1915, p. 267. 266 — Ventral abdominal segments without median sucker-like dise; thoracic segments without chitinized plates, or if these are present - they are not noticeably larger than those on the following seg- MENUS. io.d'0re dle sre bua is Wiel alailaiels wietepehe se tNeeeats kee alors) aia re tema 2. 2.« Apical abdominal segment short and stout, with 4 small protuber- ances which are fringed with soft hairs............: .Pericoma*. — Apical abdominal segment usually conspicuously elongated, in the form of a chitinized tube; apical protuberances and fringes short opt Ae Ose Be, CRO. Dees Lae eee ere Psychoda*.- PUPAE 1. Pupa flattened, about twice as long as broad, oval in outline, the abdomen laterally not narrower than the thorax, without spines, apical segment rounded..... Maurina (Pericoma) californiensis. — Pupa not flattened, more than 3 times as long as greatest breadth, abdomen well differentiated from thorax and with transverse series of spines, apical segment not rounded................--- SE erat) Oe oror ana nee See o Pericoma and Psychodat. Maurina (PERICOMA) CALIFORNIENSIS Kellogg Pericoma californiensis Kellogg, Ent. News, Vol. 12, 1901, p. 46. Larva and ponouna californica Kincaid, Ent. News, Vol. 12, 1901, p. 195. Imago. The above synonymy is the reverse of that given in Aldrich’s Cata- logue, but must be accepted because of the following facts. It is suf- ficient for the purpose of identifying a species that either the larval or pupal’ stage be accurately or recognizably described; Kellogg de- scribed and figured both larva and pupa and described the habits of the species in February, whereas the description of the adult by Kin- caid did not appear until the following September. The fact that Kel- logg gives Kincaid as authority for the name californica in the legend to his figures of larva and pupa does not alter the status of californien- sis, for Kincaid’s name, californica, had no standing until published by him in September ; and that he was in no way responsible for either Kellogg’s descriptions or figures seems evident from the absence of acknowledgment to that effect in Kellogg’s paper. *The last two genera are separated by the use of characters that appear to apply very well to the groups as far as they are known, but within the composite genus Psychoda there are larvae that differ in such degree as to warrant their fur- ther subdivision. +I know of no reliable characters that can be used in the separation of the pupae of Pericoma and Psychoda. My material is confined to the latter, a key to part of which is given herewith. 267 The generic name Maurina was first used by Muller for a group of 3 species found by him in southern Brazil in situations similar to those in which californiensis occurs—rather swift running water*. The larvae agree with the larva of californiensis and differ from others belonging to Pericoma in having a medio-ventral series of sucker-like discs, one on each abdominal segment except the last, and the pupae, with their oval shape and flat appearance, conform to the same grouping. Eaton has subdivided the genus Pericoma into sev- eral genera, but upon adult characters only. I have not seen any stage of califormiensis, no suitable situations for its occurrence being in this part of the state. The wing venation of the imago as figured by Kincaid differs from that of the normal Pericoma, and in the absence of the base of the anterior branch of the posterior furcate vein resembles that given by Muller for the Brazilian species. PsycHopa Meigen Keys To SPECIES LARVAE 1. Thorax without well-defined chitinized transverse plates......... 2 — Thorax with well-defined chitinized plates................-..4-- 6 2. Abdomen without chitinized dorsal plates................ minuta. — At least sixth and seventh segments with chitinized dorsal plates. .3 3. Sixth and seventh abdominal segments each with 3 chitinized trans- ETC mC OLA el atesyare must aiees dies Sete ces eines a fares s Ova el sisaudi blo ates, vuole 4 — Fifth, sixth, and seventh abdominal segments with chitinized trans- WETS COMER TENSE Sein pp cochco ae ore el orc GiCTe CRO GREREO Ich ONT Oe Ire 5 4. Thoracic and abdominal segments, except sixth and seventh, each with a closely approximated pair of hairs on a small cireular plate near the posterior lateral margin.................. nocturnala. — Thoracic and abdominal segments without such hairst....schizura. 5. Fifth, sixth, and seventh abdominal segments each with 3 chitinized GANS V ECR 1 OTSA np LATCH Vere. nrcuiiey 6) «/m sce elceeheyeyrre vies. & albimaculata. — Fifth and sixth abdominal segments each with 3 chitinized trans- verse dorsal plates, seventh with 2.................... floridica. 6. Prothoracie segment with one chitinized plate, metathoracic seg- 7 ment with 2 such plates; abdominal segments, except 6 and 7, MeL OM CHIIMIZEM MLALES celel tere eanvele iste evelecties siecsip ace alternata. — -EKach thoracic and abdominal segment with a chitinized plate on eC AMINA UDCA PE yates tac tiesto es ch Fa BA oop oy iyoic a ons (o tony tilebSu ay Srivaielshor’ 7 *Trans. Ent. Soe. London, 1895, p. 480. tNeither mentioned in description nor drawn in figures by Fullaway, so assumed to be absent. =a 268 All chitinized plates with several long and conspicuous bristles; apical respiratory tube short and stout (Pl. XX XIX, Fig, 8)... . gan ai byelogb aye abe fobeiien niet le logs te ele aetstm sol a) sietas teal Remo atta de ote superba. Chitinized plates with at most very inconspicuous bristles; apical respiratory tube very distinetly elongated and tapering apically .8 Robust species; basal abdominal segment with narrow transverse chitinized plates.............. cesses ee eeee ene eneeeeeee sp. ? Slender species; basal abdominal segment with spot-like chitinized PLATES S25 Teicca's celstond love a6) eters al wate ect ey onelplaueleneetete ous cterele cinerea®, ° PUPAE Ventral abdominal segments each with 3 transverse series of spinules, the anterior and posterior marginal series compact, the one on middle of segment consisting of 4 widely separated BPI ULES A syshc separa eidherteeetlsieke Pele Eee nee ks eee ee eee minuta. Ventral abdominal segments each with 2 transverse series of spinules, the widely separated median series and the compact posterior marginal: OWE as we yersayareisterster-ttoeicyatel oveliedeye aro ate 2 Prothoracie respiratory organs as long as greatest width of thorax; first 2 ventral abdominal segments beyond apex of wings each with 2 spinules in median transverse series...........alternata. Prothoracie respiratory organs much shorter than greatest width of thorax; at least the second ventral abdominal segment beyond apex of wings with 4 spinules in median transverse series...... 3 Prothoracie respiratory organs with-groups of openings, not with a continuous series on surface; second dorsal abdominal segment with distinct apical transverse series of spines, the series on seg- ments 3 to 7 with a pair of single long spines close to middle, and another between these and lateral extremity of series, the latter paired! (PT XEXe RIX Boa Ayia Sacre steiner merce sroietet tere cee superba. Proiiaeaaie respiratory organs with continuous series of openings, not groups; abdominal armature not as above........ sieeve First ventral abdominal segment beyond apices of wings with 2 spinules in median transverse series.............. albimaculata. First ventral abdominal segment beyond apices of wings with 4 spinules in median transverse serieS..............-0005 cmmerea. PsyCHODA MINUTA Banks Psychoda minuta Banks, Can. Ent., Vol. 26, 1894, p. 331. Larva (Pl. XXXIX, Fig. 7).—Length, 2.75-3 mm. Whitish testaceous, apex of anal respiratory tube dark brown. Head distinctly longer than its greatest width; maxillae promi- nent, their palpi protruded, fringed; antennae very minute. Pro- *See remarks in text under domestica. 269 thoracic spiracles slightly elevated; second annulus of segment with indications of a dorsal plate; remaining thoracic and abdominal seg- ments without dorsal plates; divisions between thoracic and abdomi- nal segments distinct, the annuli very poorly defined; surfaces of both thoracic and abdominal segments densely covered with very short pale hairs, the only distinguishable setulose hairs being on lateral mar- gins of posterior annuli of segments. Apical abdominal segnient tube- like, chitinized but not conspicuously darker than preceding segments, its length about 3 times as great as its greatest width; apical papillae very small, fringes short (Fig. 9). Pupa.—Length, 2 mm. Yellowish testaceous. Prothoracic organ (Pl. XXXIX, Fig. 5) of moderate size, taper- ing apically, and with a series of small spiracle-like protuberances along one side; eyes large; antennae considerably thickened (male) ; front view of head and appendages as in Figure 16. Abdominal ar- mature weak; dorsal segments, except basal, each with a transverse posterior series of widely separated spinules and an interrupted medi- an series of very minute setulae (Fig. 17); ventral segments (Fig. 18), except the apical one and those below wings, each with a posterior and anterior transverse series of closely placed spinules and a median transverse series of 4 rather widely placed spinules; apical segment with 3 spines on each side, the two lower ones very closely placed; apical thorns on upper margin strong (Fig. 1). The above descriptions were drawn from larvae and pupae ob- tained from cow dung in November, 1915, and April, 1916, the for- mer at Urbana and the latter at White Heath, III. The small size of this species makes it a very difficult one to rear and isolate the stages and exuvia successfully. Originally described from Sea Cliff, N. Y., and subsequently re- corded from Mesilla, N. Mex. Probably of general occurrence throughout North America. PsYCHODA SUPERBA Banks Psychoda superba Banks, Can. Ent., Vol. 26, 1894, p. 332. Larva (Pl. XXXIX, Fig. 13).—Length, 5-5.5 mm. Grayish white; head, chitinized dorsal plates, and apical segment brown. Dorsal surface-of head with several long hairs; antenna termi- nating in 2 stout bristles and 2 weak hairs (Fig. 12). All thoracic and abdominal segments with a single large chitinized plate on dorsum of each annulus, those of prothoracic and first mesothoracic annuli 270 narrowly interrupted on middle line; prothoracic spiracle elevated, the ~ protuberance nearly twice as long as thick. Membranous portions of thorax and abdomen covered with numerous very short spinules; chitinized plates on dorsum with a number of long hairs and many short spines (Fig. 8) ; anterior and posterior annuli of abdominal seg- ments each with long lateral hairs, the median one with a short, stout lateral protuberance which has the appearance of a rudimentary spir-— acle; ventral segments with a transverse series of long hairs on each of tle intermediate (4) and posterior (4-6) annuli, those on the former inserted in small round dark plates; apical segment about 1.5 as long as wide, armed with a number of dorsal and lateral hairs, ven- tral surface with a large chitinized plate. the rounded apex of which is armed with a fringe of long stiff hairs; laterad of this plate and near its margin is a small rounded plate upon which are 2 long hairs; apex of segment above terminating in 4 short clubbed processes which are fringed with a number of long radiating hairs (Fig. 15). Pupa (Pl. XXXIX, Fig. 10),—Length, 3.5 mm. Brownish tes- taceous, not shining. Prothoracic respiratory organs (Fig. 6) slightly tapering at base and apex, surfaces honeycombed or shagreened and with a number of small tracheal openings. Ventral aspect of pupa as in Figure 10, the transverse abdominal armature in 2 rows on each segment, the anterior row consisting of 4 widely placed spinules on disc and one on each lateral margin, the posterior row of numerous closely placed spinules, the apices of some of which are irregularly dentate; dorsal segments, except basal, each with a single transverse series of spinules on posterior margin which is similar to that on ventral segments, and - also, like that series with 4 longer hairs (Fig. 4) ; apical segment with the upper posterior margin armed with 2 very short thorns, the lower posterior margin with 2 long, curved thorns (Fig. 2). The foregoing descriptions are drawn from larval and pupal ma- terial obtained from water in a tree-hole in the forestry of the Uni- versity of Illinois at Urbana June 2, 1916. The duration of the pupal stage averaged three days under laboratory conditions. The species was originally described from imagines obtained at Sea Cliff, N. Y., and has been recorded from Battle Creek, Mich. I took imagines on tree-trunks at Urbana in July and August, 1915. The larva bears a striking resemblance to that of Pericoma canes- cens Meigen as figured by Miall and Walker*, but differs in the ar- *Trans. Ent. Soc. London, 1895, Pl. IIT. 271 rangement of the hairs both on the dorsal plates and on the ventral surface, and also in the form of the apical segment. There are nc outstanding differences in the pupae of the two species. PsycHODA DOMESTICA Haseman Psychoda domestica Haseman, Ent. News, Vol. 19, 1908, p. 282. The immature stages of this species were described by Haseman. I suspect that the species is a synonym of cinerea Banks. The only difference between the larva described by Haseman and that de- scribed as cinerea in the present paper lies in the absence of the small plates on the basal abdominal segment in domestica. ‘These are dif- ficult to see in fresh material, and may have been overlooked by Hase- man, Described from specimens obtained from plant cultures in a lab- oratory at Columbia, Mo. PsYCHODA CINEREA Banks Psychoda cinerea Banks, Can. Ent., Vol. 26, 1894, p. 330. Larva (Pl. XXXIX, Fig. 11).—Length, 4.75-6 mm. Whitish testaceous, the head, chitinized plates on dorsum, and the apical seg- ment fuscous brown. Head posteriorly sinuous in outline above, 2 small, narrow, dark plates on the membrane posterior to the central concavity. Thoracic segments each with 2 chitinized dorsal plates; prothoracic annuli each with 2 hairs on each side just in front of the outer half of the plates, these hairs being duplicated in the second annulus, each pair consist- ing of 2 hairs on a single base; second and third thoracic segments with similar hairs on posterior annuli, the anterior annuli without them; respiratory organ of moderate size, protruded. Basal abdomi- nal segment biannulate, each annulus with a very small dorsal plate; following segments triannulate, the size of the dorsal plates on the anterior segments small, increasing posteriorly until on the last an- nulus of seventh segment the plate covers one half of the dorsal area; posterior annuli of all segments with a pair of duplicated hairs on each side, the other segments without long hairs; lateral margins of each of the posterior annuli with 2-3 long hairs; apical abdominal segment long and tapering, the terminal appendages small and slen- der; ventral segments each with a pair of long hairs on each side of the posterior annuli, the discal hairs, especially on middle of annulli, much longer and stronger than on dorsum, their apices bifid or trifid. 272 Pupa.—tLength, 2.5-3.5. Prothoracic respiratory organ very similar to that of minuta, the openings of tracheae paired to base; apices of hind tarsi projecting very slightly beyond apices of wings. Armature of abdominal segments similar to that of swperba but dis- tinctly weaker, especially on apex of second dorsal segment, where the spinules are not well defined; apical segment with both the upper and lower pairs of apical thorns rather strong, the armature as in . Figure 3, Plate XX XIX. The foregoing descriptions are drawn from larvae and pupae which I obtained from a water trough in the dark room of the labo- ratory here in June, 1916. ‘The pupal stage lasts from 3 to 5 days. The trough is not properly leveled, and along one side a small amount of water periodically accumulates which because of its unfiltered con- dition is soon permeated with an algal growth, in which the larvae feed. Haseman’s figure of the larva of domestica does not show the plates on the second abdominal segment. His description indicates that he found some variation in the number of plates on the basal 3 segments. My material does not show any variation. Muttkowski’s figure of the larva of cinerea does not show the dor- sal hairs, but probably he overlooked these. PsyCHODA ALBIMACULATA Welch Psychoda albimaculata Welch, Ann. Ent. Soe. Amer., Vol. 5, 1912, p. 411. Full descriptions of the larva, pupa, and imago are given by Welch in the paper above cited. I have before me the same stages, obtained in the reservoirs at the 35th street pumping-station in Chicago. Welch’s material came from the same reservoirs. PsyCHODA sp. ? Larvae of a species closely allied to domestica were obtained from a wound in a mulberry-tree, from which sap was exuding, at Urbana in July, 1915. My material is not plentiful enough to permit a defi- nite decision regarding the specific identity of the species. A figure of the larva is given herewith (Pl. XXXIX, Fig. 14). References to descriptions of immature stages of other North American species are given in the following list of notes and papers, the species dealt with being placed in parentheses in each case. 273 PAPERS DEALING WITH BIOLOGY oF PSYCHODIDAE Dell, J. A. 05. Structure and life history of Psychoda sexpunctata {al- ternata]. Trans. Ent. Soe. London, 1905: 293-311. Eaton, A. E. 95. Supplementary notes on Dr. Fritz Miller’s paper on a new form of larva of Psychodidae (Diptera) from Brazil. Trans. Ent. Soe. London, 1895: 489-493. Fullaway, D. T. : 07. Immature stages of a psychodid fly. Ent. News, 18: 386-389. (Psychoda schizura.) Haseman, L. 707. A monograph of the North American Psychodidae, including ten new species and an aquatic psychodid from Florida. Trans. Amer. Ent. Soc., 33: 299-333. (Psychoda floridica.) 708. Notes on the Psychodidae. Ent. News, 19: 274-285. (Psychoda domestica and P. nocturnala.) 10. The structure and metamorphosis of the alimentary canal of the larva of Psychoda alternata Say. Ann. Ent. Soe. Amer., 3: 277-808. Johnson, J. W. H. 14. A contribution to the biology of sewage disposal. Jour. Econom. Biol., 9: 105-124, 127-164. Kellogg, V. L. i 701. An aquatic psychodid. Ent. News, 12:46-50. [Pericoma (Maurina) californiensis.] . Knab, F. 13. New moth-flies (Psychodidae) bred from Bromeliaceae and other plants. Proce. U. S. Nat. Mus., 46: 103-106. Miall, L. C., and Walker, N. 95. The life history of Pericoma canescens.* Trans. Ent. Soe. Lon- don, 1895: 141-147. Miller, F. 95. Contribution towards the history of a new form of larvae of Psychodidae (Diptera) from Brazil. Trans. Ent. Soc. London, 1895 : 479-482. Muttkowski, R. A. 715. New insect life histories. Bull. Wis. Nat. Hist. Soc., 13 (No. 2): 109. *Deals with a European species, but listed because referred to in this paper. 274 Osten Sacken, C. R. 95. Remarks on the homologies and differences between the first stages of Pericoma Hal., and those of the new Brazilian species. Trans. Ent. Soe. London, 1895: 483-489. Welch, P.S. 12. Observations on the life history of a new species of Psychoda. Ann. Ent. Soe. Amer., 5: 411-418. (Psychoda albimaculata.) In addition to the foregoing, there are a number of excellent pa- pers by Haliday, Koch, Zuelzer, Jacobfeurborn, and others, dealing ~ with the larvae and pupae of European species. Family BLEPHAROCERIDAE FAMILY CHARACTERS Larva.—Head, thorax, and first and second abdominal segments fused; a slight transverse depression between the anterior margin of first.abdominal and the posterior margin of the metathorax; a stout thorn on each lateral margin of one of the fused abdominal segments (second?) as on the other abdominal segments. Dorsal sclerites of head well defined; antenna well developed, slender, with 3 well-differ- entiated joints; mandibles opposed, strong; maxillary palpi rudimen- tary. Abdominal segments with very deep lateral constrictions be- tween them, the protruded median portion of segments 3 to 7 each with I or 2 stout horns; apical segment rounded, without a horn or with a shorter one than those of the other segments. Sometimes the dorsum has a number of stout thorn-like protuberances in addition to those on lateral margins. Venter with a median longitudinal series of disc-like suckers, usually 6 in number, one on the thoracic complex, and one on each of the succeeding abdominal segments. Laterad of these suckers is a group of filaments which resemble the protruded ventral blood-gills of some species of Chironomus and may perform the same function. Pupa.—Slug-like, ventrally unchitinized and flattened, so that it adheres closely to the rock bottom of the stream, dorsally convex and chitinized, the segments of abdomen distinct, but no noticeable con- striction between base of abdomen and apex of thorax, the outline un- broken, oval. Thoracic respiratory organs lamellate, distinctly ele- vated. Legs extending nearly to apex of abdomen. Imago.—Tipulid-like, body and legs very long and slender, wings large, with many reticulate creases between the veins, the effect pro- duced being that of a secondary venation. 275 HABITS OF LARVAE The larvae of all species are aquatic, living in swift-running streams, and particularly in those that have rocky bottoms—to which they attach themselves by means of the suckers on the ventral surface of their bodies. The food consists of diatoms, algae, and other small aquatic or- ganisms. HABITS OF IMAGINES The imagines are never found except in the vicinity of streams suitable for their larvae. The females are predaceous, feeding upon small insects such as chironomid midges; the males are recorded as feeding on nectar. Owing to the fact that the larvae require very rapidly flowing pure water as their habitat no species are likely to be found except in moun- tainous regions, and it is improbable that any occur in Illinois. BIBIOCEPHALA Sp. ? Larva (Pl. XL, Fig. 1).—Length, 9-10 mm. Pale brown on dor- sum, yellowish white on venter; head and chitinized dorsal thorns black. Antennae elongate, constricted portions of joints whitish, the re- mainder black; entire dorsum of head chitinized, black; mouth-parts pale. Thoracic segments without thorns; a black triangular chitinized area on dorsum proximad of the first abdominal armature. Last segment of complex and all the abdominal segments except the apical with 4 stout horn-like protuberances on middle of dorsum, a much longer one near each lateral margin, and a pair of them on lateral margin, the upper one, with a shoulder at its middle, directed outward and armed at apex with 2 long hairs, the lower one directed slightly downward; apical segment with a pair of protuberances on dorsum and a number of long hairs on margin of apex of venter. Ventral suckers of moderate size. Lateral ventral blood-gills 5 in number in each group; apical blood-gills stout, 4 in number. Pupa (Pl. XL, Figs. 2, 4).—Length, 6.5-8 mm. Dark brown. Thoracic respiratory organs consisting of the usual 4 upright plates (Fig. 6), the length of the outer one being about 1% times as great as its greatest width. Dorsal surface covered with minute, slight- ly raised dots; each abdominal segment with a group of larger black- ish dots on each side about midway from median line to lateral margin, and between this group and the lateral margin a slight eleva- 276 tion. Ventral aspect as in Figure 2, the apices of legs not in a straight transverse line. In another specimen—which may be another species or the other sex of the present one—the legs terminate in an almost straight line. Described from specimens collected in Jenny Creek, Tolland, Col., July 12, 1916 (B. Green). The larva of this species differs from any other described from North America in the armature of the dorsum. In some species of Bibiocephala the larvae have indications of chitinized points, or warts, on the dorsum, but in none are they so well developed as in the pres- ent species, the nearest approach being an unnamed Colorado species figured by Kellogg in his revision of the group, Figures rr and 12 of his paper (’oob). Prof. T. D. A. Cockerell informs me that the only species re- corded from the region where Miss Green obtained the larvae and pupae of the above species is Bibiocephala grandis Osten Sacken. It is not improbable that the larvae belong to this species, but on the evidence at hand I do not feel justine: in suggesting that uo do. Principat Parers oN NortH AMERICAN BLEPHAROCERIDAE Kellogg, V. L. 700. Notes on the life-history and structure of Blepharocera capi- tata Loew. Ent. News, 11: 305-318. 00a. A new blepharocerid. Psyche, 9: 39. ’00b. The net-winged midges (Blepharoceridae) of North America. Proe. Calif. Acad. Sci., ser. 3, Zool., 3: 187-232. 07. Blepharoceridae. Gen. Ins., Fase. 56. Riley, C. V. 81. Note on Blepharoceridae. Am. Nat., 15: 438-447. Family CULICIDAE No family of Diptera has received so much attention within the past twenty-five years as the Culicidae. This is due entirely to the fact that they are of very great economic importance, since in addi- tion to their being in most cases a great annoyance to man because of their bloodsucking habits several species are directly instrumental in the transmission of various fevers, and other diseases, prevalent in the warmer parts of the world—such as malaria, yellow fever, and filariasis. ‘The literature on the family is remarkably copious, and as it is generally accessible in America it is not the purpose of the writer bo u on to give an extended review of the species here, the principal divisions being indicated only. Students who may desire a fuller knowledge of the family characters should consult the papers listed herewith. I have retained Dixidae as a distinct family, contrary to the opin- ion of some writers who consider that the group should be ranked as a subfamily of Culicidae. FAMILY CHARACTERS Larva.—Head large, complete, exposed; mandibles moving hori- zontally ; antennae well developed; mouth-brushes present (Culicinae ) or absent (Corethrinae, pt.). Thoracic segments fused, appearing as acomplex mass. Respiration carried on by means of posterior spiracles which open on last segment, their tips frequently in the form of elongated tubes, by means of which the larvae obtain a direct con- nection with the air by piercing the surface film of the water in which they live. In some of the Corethrinae there are present in the thorax and in the apex of the abdomen a pair of air-sacs which are usually black and conspicuous, contrasting with the glassy appearance of the larval body. These species do not keep a.connection with the air, and are frequently found at great depths in lakes. Body with more or less conspicuous hairs or hair tufts. Pupa.—As in the larvae, the thorax is conspicuously swollen; the respiratory organs are placed well back on the sides of the disc of the thorax—a characteristic that distinguishes the family from the Chiro- nomidae. ‘The abdomen has conspicuous hairs, some of those on the dorsum being stellate, and its apex is usually armed with 2 or 4 large, flat, paddle-like organs. Imago.—Readily distinguished by the tomentose or scaled wings, slender build, long legs, complete marginal wing-vein; and by the absence of ocelli, of discal cell of wing, and of the v-shaped dorsal thoracic suture. HABITS OF LARVAE The larvae are aquatic, living under a variety of conditions, some of them in very deep water in lakes, some in shallow permanent pools, others in ditches that offer a permanent breeding-place or in water in depressions or receptacles that are of a temporary nature. ‘The food of the species differs considerably, some of them being almost entire- ly vegetarian in habit, feeding on decaying detritus in the water or upon algae, while others are predaceous, feeding upon insect larvae and other small animals. 278 HABITS OF IMAGINES The female imagines of the Culicinae are almost entirely blood- suckers though some are found also upon flowers. Some species are the only known vectors of certain diseases, such as malaria, yellow fever, and filariasis. On account of this latter fact a very voluminous literature has appeared within the last twenty years, a brief list of some of the more recent and important works being given at the end of this summary of the family. rl a pl — Keys To SUBFAMILIES LARVAE Apex of abdomen with a long respiratory tube.................. 2 Apex of abdomen without elongate respiratory tube............. 3 Antennae pendulous, hanging down in front of head and armed with 4 long and strong apical bristles (Pl. XLI, Fig. 1), or when at rest folded back against sides of head and armed with 2 or 3 stronevapicaliclawsa. serene eee eee eki eee CoORETHRINAE, pt. Antennae porrect, not pendulous nor folded back against sides of head when at rest, and usually with a few weak bristles and one or two pointed processes (Pl. XL, Fig. 3)........ CuLicrnak, pt. Anal segment cylindrical; last segment with a flat dorsal area in which are 2 spiracles; thorax and abdomen without black air-saes POA cL GOIN NID IG PRO AE LOSI OO Boe Onc 0's" c CULICINAR, pt. Anal segment either bladder-like or the last segment with no spira- cles and the larva transparent, glass-like; a pair of black air- sacs in thorax and another in seventh abdominal segment (PI. 9:41 el it: da ety Re rte eee a b.8 cine kb CORETHRINAE, pt. PUPAE Apical abdominal appendages acutely pointed... .CORETHRINAR, pt. Apical abdominal appendages rounded..............+++++e000: 2 Thoracic respiratory organs elongate-oval, pointed at apex, black, contrasting sharply with color of thorax....... CORETHRINAE, pt. Thoracic respiratory organs more or less trumpet-shaped, never elongate-oval or pointed at apex, generally but little darker than thorax i(BIE EX) Hick) eerie erie tel es he ine CULICINAE. IMAGINES Proboscis short, not adapted for piercing........... CORETHRINAE. Proboscis very long, adapted for piercing............. CULICINAE. 279 SoME OF THE MORE IMPORTANT WorKS ON NortH AMERICAN CULICIDAE Felt, E. P., and Young, D. B. 94. The mosquitoes or Culicidae of New York State. Bull. 79, N. Y. State Mus. Howard, L. O. 700. Notes on the mosquitoes of the United States. U.S. Dept. Agr., Bur. Ent., Bull. 25, n. ser. 10. Preventive and remedial work against mosquitoes. U.S. Dept. Agr., Bur. Ent., Bull. 88. Howard, L. O., Dyar, H. G., and Knab, F. 712. The Mosquitoes of North and Central America and the West Indies. (In 4 volumes, one of which is yet to appear.) Johannsen, O. A. 703. Aquatic Nematocerous Diptera. Bull. 68, Pt. 6, N. Y. State Mus., pp. 388-429. (Part of a comprehensive report, by various authors, on the aquatic insects of New York State.) Family DIXIDAE This is a small family, containing but one genus and about a score of described species. Some authors have considered them as forming a subfamily of Tipulidae, while others have placed them in the Culic- idae. I am of the opinion that they are entitled to family rank, and so treat them in the present paper. FAMILY CHARACTERS Larva (Pl. XL, Fig. 5).—Head complete, not retractile, antennae and maxillary palpi long and slender, mandibles opposed, stout; maxillae with a fringed lobe homologous with that of Simuliidae (PI. XLI, Fig. 5); labium chitinized, densely hairy (Pl. XLI, Fig. 3). Thoracic segments distinct, similar in form to those of abdomen, the first 2 armed on anterior margin of dorsum with several long hairs. Tirst and second abdominal segments each with a pair of pseudopods on dorsum, the apices of which are armed with curved spines; dor- sum of segments 5, 6, and 7 each with a transverse pair of slight ele- vations which are armed with closely placed spines, or the segments with a transverse band of spines posteriorly; ventral surface of some of the abdominal segments usually with flattened areas which are armed on their margins with spines; preapical segment with a pair, or more, of long hairs; apical segment terminating above in a chitin- 280 ized tube-like process, which is armed with a number of long hairs, and ending below in a pair of slightly pointed processes which are- fringed with closely placed hairs. Pupa (Pl. XL, Fig. 7).—Antennae extending to or beyond middle of wings; palpi forming a semicircle, their apices incurved in front of clypeus; eyes rather small. Thoracic respiratory organs elevated, funnel-shaped; legs recurved against: base of abdomen. Abdomen with 3 rather distinct sharp ridges on each segment, the apices of which are slightly serrate; apical segment terminating in 2 long, pointed processes; apical half of abdomen directed cephalad because of the curvature of the body, thus closely resembling the pupae of Culicidae. Imago.—See key to imagines of Nematocera. HABITS OF LARVAE The larvae are aquatic, living in shallow wells, and in clear water such as is found in springs and slow-flowing mountain streams. The food consists of algae. HABITS OF IMAGINES The imagines occur in the vicinity of streams and may be swept from grasses or other vegetation overhanging the water. I have found them very commonly among grasses on almost perpendicular rocks that were continuously wet owing to water dripping over their surface. They have poorly developed mouth-parts, but I have found them on flowers, evidently feeding on nectar. I have before me examples of the larvae and pupae, some of which were obtained by Mr. Hart at Havana, IIl., and others by Dr. S$. A. Forbes in Yellowstone National Park. ‘They differ from the species described by Johannsen in the armature of the abdomen and the struc- ture of the apical segment, and’ in a few other particulars. PAPER CONTAINING Account or NortH AMERICAN DIXIDAE Johannsen, O. A. 703. Aquatic Nematocerous Diptera. Bull. 68, Pt. 6, N. Y. State Mus., pp. 429-482. Superfamily Chironomoidea This superfamily contains 3 families, Chironomidae, Ceratopogon- idae, and Orphnephilidae. 281 The position of the last-named family has been somewhat in dis- pute amongst taxonomists, but the larval and pupal characters un- doubtedly ally it more closely with Chironomidae than with any other family. SUPERFAMILY CHARACTERS Larva.—Head complete; antennae elongate, except in some Cera- topogonidae, retractile in Tanypinae; labial plate flat, usually notched anteriorly. Thorax and abdomen with distinct segments, 12 in number ; pseudopods present upon prothorax and apical abdominal segments, on prothorax only, or entirely absent; respiration carried on by means of lateral prothoracic, abdominal, and anal spiracles, or by apical spiracles and anal blood-gills, or by the latter alone. Some- times the anal blood-gills are permanently exserted and located on the latero-ventral margins of the apical segment, but usually they are en- tirely or partly retractile, or they are situated at apex of last segment and are somewhat leaf-like and not retractile. Pupa.—Head without chitinized protuberances; antennae curved over eyes. Thoracic respiratory organs elevated, usually in the form ef a single tube, and not uncommonly filamented, rarely sessile. Legs in Chironomidae recurved against base of venter of abdomen and apex of thorax; in the other families straight and not at all, or but slightly, exceeding length of wings. Abdomen in Chironomidae and Orphne- philidae with or without weak dorsal setulae, in Ceratopogonidae with leaf-like or thorn-like bristles; apical segment in Chironomidae usually with 2 or 4 pointed thorn-like protuberances. Imago.—Antennae consisting of 6 to 15 joints; palpi 2- to 5- jointed, pendulous; proboscis in Chironomidae and Orphnephilidae poorly developed, in Ceratopogonidae well developed and chitinized. For synoptic characters see key to imagines on a previous page. Family CERATOPOGONIDAE After a careful examination of all the stages of this group and a comparison of these with the various stages of other families of the suborder I have decided to separate it, as a family, from Chironomi- dae, in which it has been previously placed as a subfamily. FAMILY CHARACTERS Larva.—Head complete (Pl. XLI, Fig. 15) ; mandibles (Pl. XLI, Figs. 13, 14) opposed, toothed or simple and hook-like; labium dis- 282 tinct; antennae small (Pl. XLI, Fig. 11). Respiration carried on by means of posterior spiracles or apical abdominal protrusive blood- gills; in the terrestrial forms I am unable to find lateral abdominal spiracles. Abdomen in aquatic forms worm-like, without pseudopods (Pl. XLII, Fig. 6), the only hairs present confined to apex of last segment ; abdomen in terrestrial and semiaquatic forms with numerous bristles (Pl. XLII, Figs. 1, 2, 3, 4), the truly terrestrial species with distinct prothoracic and anal pseudopods, and some of the bristles on body leaf-like or lanceolate (Pl. XLI, Figs. 6, 7, 8,9, 10). Pupa (Pl. XLIU, Fig. 5).—Head without thorns. Thorax com- pact, the wings and legs fused together and to thorax; apices of legs not, or but slightly, exceeding apices of wings, not recurved; thoracic respiratory organs elongate; disc of thorax in terrestrial forms with a number of long bristles. Abdomen with bristles or leaf-like pro- tuberances ; apical segment terminating in 2 or 4 thorns. Imago.—Antennae in both sexes consisting of 15 joints, the apical 3, 4, or 5 usually noticeably longer than the others; male antennae plumose, that of female short-haired; mouth parts chitinized, fitted ~ for piercing. Thorax not much arched, not overhanging head. Wings short; venation similar to that of Chironomus. Legs stout, the fore and mid pairs shorter than the hind pairs. HABITS OF LARVAE The larvae of Forcipomyia are terrestrial, feeding on cow dung, under bark of trees, and in decaying vegetation, and rarely they are found under decaying drift on the margins of rivers. The larvae of Ceratopogon occur on decaying wood in water, usually on submerged logs; those of Culicoides are also aquatic, occurring in tree-holes and in streams; while a species of Pseudoculicoides is found in exuding tree-sap. All species of other genera known to me are truly aquatic. HABITS OF IMAGINES The species of Culicoides are the well-known “punkies” and are in- variably bloodsuckers. Pseudoculicoides is also a blood-sucking ge- nus. I have no record of this habit for any of the other genera in so far as man and domestic animals are concerned, but they attack insects, attaching themselves to the body and wings. ls lrol 283 Keys To GENERA LARVAE Pseudopods present on prothorax and apical abdominal segment. .2 Pseudopods absent, body worm-like (Pl. XLII, Fig. 6)........... £30. EC MOR nee een a Pseudoculicoides, Culicoides, Palpomyia, ete. Body circular in cross-section, armed with long bristles, some of which are leaf-like (Pl. XLII, Figs. 1, 2,3)........ Forcipomyia. Body flattened, oval in cross-section, armed with short simple bris- RC gy Ube ee Te OML se Es) ares aatrtetier dead Pavol sie cries, oye sa = Ceratopogon. PUPAE MO ras wit hOUbs lON GMDPISHCS si. myers cite ct oeeres «el erere ema eee tins 2 Morass vu LONG DTISGES 3. cre tetyslrs couse > sos scale is os see ne 3 Thorax with short, pointed protuberances............. Culicoides. Thorax without distinct protuberances, at most with slight eleva- HVOTISH (Cha lee CUM AMO oD) ous c uate yap ucVenevore coho. apeds’ +6 Palpomyia, ete. Second abdominal segment with 4 bristles........... Ceratopogon. Second abdominal segment with about 10 bristles. ..... Forcipomyia. IMAGINES Wings with distinct hairs on disc, either in the form of short up- right microscopic setulae or broad decumbent scales.......... 2 Wings without hairs on disc, rarely with a few near apex of costal a AOU Ree Ie a ers lars Ccic rs er eucedhe elienayiar etek cca Walia wer si wevaava ote 6 Thorax with a distinct slit-like or cireular depression on each side of dise slightly caudad of the inner angle of prothorax........ NIE SIRS oss rey eyo mt nner ho shou cena Sais Mofo madiarare ied Culicoides. Mboraxawithout these Gepressions. . sss woe. 2. ces es we oieisie so eee 3 Wings densely hairy, decumbent scale-like hairs present on whole SHAUNCB 5p SUS O49 HOE 0 ETE COC ete Ee crake Rca Totes rere 4 Wings with upright hairs which are usually absent on anal angle, MOESCa eH Uke an alhse ESCM er ay eue a, suse leis: oy01s.5) eke eur esan cates ace oe 5 Basal joint of hind tarsi shorter than, or at most as long as, second 3. 0 eo 01 OI SEELEY ENOTES CD CITC CCIE ERE Forcipomyia. Basal joint of hind tarsi very much longer than second.......... nit, Bee. OCI OR CRORES TELE OL CLO CIC oe Reena Euforcipomyia. Empodia absent; first and third veins of wings fused; tarsal claws of female very unequal in length.............. Neoceratopogon. Empodia present; first and third veins of wings connected by a cross-vein; tarsal claws of female equal........... Ceratopogon. ..rst and third vein connected by a cross-vein or fused basally. ..7 Hirst a1 third veins disconnected for their entire length....... 11 284 — Pemora without ventral spines a... centers eee esl. ree 10. 8. Generally more than one pair of femora with spines; neither fore nor hind femora noticeably thickened............... Palpomyia. — Only fore or hind femora with spines, the spinose pair perceptibly thickened -4ieiiisd sb ace ie ne ee eee oe oie ‘jee foetore 9 9. Fore femora thickened and spinose................4- Heteromyia. — Hind femora much thickened and spinose............. Serromyia.. 10}. Mediampessile ws eit iyoscieat on contro eee etter Johannsenomyia. == 1 Mediaxpetiolateli 3. s2thics cana poe ae Omens Hartomyia. 11. At least one pair of femora with ventral spines................ 12 —=) Memoray NOt SPINOSee tecnico tein aerate Te Sieivtere 312 Upper pair of cephalic thorns directed forward, at most slightly divergent apically, generally slightly curved downward or head without Strong UPDeEL WOOL tart ieietet ee erciete ete ett ene 10 Head with strong thorns, or if these are absent the abdomen has the dorsal transverse armature consisting of very strong thorns and intervening long slender hairs; apices of antennae obtuse. .11 Head very rarely with strong thorns, 2 carinate elevations present on upper anterior margin; antennae with apices attenuated ; body without thorns, sometimes with bristles.............+...0.++- a PA Lower median portion of face with a closely approximated pair of stout thorns which are occasionally fused almost to apices; ab- domen with the transverse armature of the dorsal segments con- sisting of short flattened thorns and long slender hairs, the thorns . usually appearing as if attached to rather than forming a part of the abdomen and sometimes turned up at bases and apices...... AC HCE AIHO CRU CCL ORD CO DO Ig BoMBYLUDAE (p. 389). Lower median portion of face without thorns; abdomen with the transverse armature consisting of alternating long and short thorns except in Leptogaster................ ASILIDAE (p. 373). Cephalic armature consisting of 2 carinated elevations on upper anterior margin, on each of which is a very long hair; antennal sheaths raised above level of face, tapering apically, directed — downward and slightly outward; proboscis much elongated..... Fe Ani ith inner aA Ria Ae ry Abn ohs woe Boreas nig e EmpipipakE (p. 400). Similar to foregoing, but with the proboscis short................ PRPS ort Pape Ca Whe Ue rac rh eas Nanri a cae DoLicHoPopIpDAE (p. 403). . IMAGINES Empodium pulvilliform, nearly or quite as large as the pulvilli, so that 3 rounded pads or scales appear under the tarsal claws. ...2 Empodium either absent or in the form of a slender thread, with or without surface hairs, so that there are only 2 distinct pads or scales under the*barsaliclawsS. cw. ctecim + ci. cheers -usisretoreelal niet aren 8 Third antennal joint distinctly annulated or the antenna consist- ine Of more thanvs GISti Cty |OUUbSttrey ete aretel elie ieleleletche tetris 3 Antenna consisting of 3 joints, the third not annulated.......... 6 Costal vein discontinued at or close to the apex of wing......... VE au aeaee (p.315). ACANTHOMERIDAE (p. 354). Costal vein continued round apex of wing, sometimes encircling the WhOle MP OSUCLION OMAV OLN. yas arerescretetets) ePanetave ole eketePav ouster sVofohed nstatonepens 4 Squamaet very lar ceirecs cst ciesreicteere cys Preeti TABANIDAE (p. 355). Squamae small, sometimes vestigial. -- 2... 5.2.2. cee ee ore een 5 *The family Acanthomeridae is doubtfully distinct from Stratiomyiidae. I have no species of the former, all occurring in South America. 12. 13. 14. 313 Robust species, with spinose scutellum; marginal vein encircling THES so POO REE COOTER oe Cee CoENOMYIIDAE (p. 351). Slender species, with unspined seutellum ; marginal vein ceasing be- fore reaching anal angle of wing........ XYLOPHAGIDAE (p. 346). Squamae very large, inflated; robust flies, with very small heads... PREM srt arcl aie el chokckete mane laterertehalatererstinstelonets, Sisis'svs CyrTIDAE (p. 368). SSC MEMT Or VOT Vee SIT Gil ltabavaretey hataraeareiae ska sscre Ree teres. Gers eve elses castolevns tl Costa continued round posterior margin of wing................ Pane os ash iatec chai Varederek eroheiens) al ave! shoving sa akeya sys) =v acs LEPTIDAE (p. 362). Costa discontinued at apex of wing....... NEMESTRINIDAE (p. 368). Anal cell much longer than second basal, closed at or close to wing- margin, or open; third vein usually fureate.................. u Anal cell absent or, if present, shorter than second basal, or but lit- tle longer, and closed some distance from wing-margin; if the apex of this cell is long and pointed the third vein is not forked Vertex depressed, seen from in front the upper inner angles of eyes are considerably above the level of the frons; eyes always separat- CU eect Sitar Sierra tee cai aia a apth a Wey ote hegaivebatte'ns“sccuspahiy ater aust byanace ails peld « 10 Vertex not depressed, at least on a level with upper inner angles of eyes; eyes of male often contiguous...................--- 11 Fourth vein curved forward apically, ending at or before tip of _ YETI S encito Garencsd Cio DIG RO CPUC CORSON ER Myparwar (p. 370). Fourth vein not curved forward............... ASILIDAE (p. 373). . Posterior cross-vein present, i. e., second basal cell with an obtuse apex formed by a cross vein; 5 posterior cells present........ 12 Posterior cross-vein absent, i.e., second basal cell with an acute apex; rarely 5 posterior cells present, if present the fifth cell is due to the bisection of the third by a cross vein.............. 13 Fourth vein curved forward and ending before the apex of wing... Sa Riese CE OOO OOOO Ost CU CIEOR DCR ICT nr ietare APIOCERIDAE (p. 373). Fourth vein not appreciably curved forward, ending behind apex TVA Petre arsroreiattialees cer natole: sie evoudeerchersie’ oie 6 THEREVIDAE (p. 396). Fourth vein curved forward, ending at or before apex of wing; pro- boscis retracted, fleshy; antennae without apical style.......... 2 id Die OC ODER GES ETO SACI ara SCENOPINIDAE (p. 398). Fourth vein ending behind apex of wing; proboscis slender, usually much exserted; antenna usually with a style.................. “ie OH 8 CORIO CO DIAIC OCOD OC ie Pia Cert eran BomMByLmpAE (p. 389). Discal cell usually separated from the second basal, always at least one distinet basal cell; squamae small; abdomen of male usually with 7 segments exclusive of the hypopygium; black, brownish, or yellowish species, usually with chitinized proboscis.......... REM eave creep rete atte rays lstive lore aNvanas, sceretolete oLecda 4 Empmipak (p. 400). Diseal cell not separated from second basal, the basal cells small and indistinct; squamae moderately large, usually with con- 314 spicuous fringe; abdomen of male usually with 5 or 6 segments in addition to the hypopygium; metallic greenish or bluish species, usually with fleshy proboscis... DoLICHOPODIDAE (p. 403). Tribe PLATYGENYA The larvae of members of this tribe are distinguished from those of Orthogenya by the structure of the head, the plates forming it be- ing flat and straight, when not enclosed within a conical chitinized capsule, and lying on a horizontal plane when at rest. Occasionally the exposed portion of the head is heavily chitinized on the anterior half, forming a cone from whose small apical opening the mandibu- - late processes protrude. I am unable to give characters for the differentiation of the pupae of this tribe from those of Orthogenya, the species of the latter known to me being so few that a generalization based on them would prob- ably prove misleading. This tribe contains all of the Brachycera except Dolichopodidae and Empididae. Characters for the separation of these families will be found in the preceding key to different stages. Superfamily Stratiomyioidea SUPERFAMILY CHARACTERS The family Acanthomeridae is confined to tropical America and is unknown to me, but the other three families are represented in all stages in my material. Larva.—Head with the anterior half cone-shaped, permanently exserted, in Xylophagidae and Cecidomyiidae heavily chitinized, the mandibulate processes protruded through a small opening in the apex. The larvae of Stratiomyiidae have the head less heavily chitinized than do those of the other two families known to me in that stage, but the anterior half is non-retractile—a character which separates these larvae from those of other superfamilies. Many of the genera have distinguishable spiracles on metathorax and abdomen which are probably not functional. For other distinguishing characters see key to larvae of Brachycera and descriptions under family headings. Pupa.—The pupae of Stratiomyiidae are enclosed within the last larval skin—a fact which separates them from other Brachycera. The pupae of Xylophagidae and Coenomyiidae are free, and differ from those of other Brachycera known to me in having the antennae with well-defined annuli. Imago.—See key to imagines of Brachycera. 315 Family STRATIOMYHDAE The larvae of this family are readily separated from those of any allied family by their characteristic general appearance (Pl. XLVI, Figs. 1, 2, 3), and the finely shagreened surface of the body. All the genera so far described have larvae that differ appreciably in the following details: head structure, chaetotaxy, indentation of lateral margins of abdominal segments, length and structure of the apical segment, and structure and armature of the anal respiratory chamber. In the aquatic forms the apical respiratory chamber, which contains the openings of the spiracles, is furnished along its margins with long plumose hairs. When the larva is close to the surface of the water the anal extremity is curved upward till the tips of the respiratory or spiracular chamber are free of the water, the radiating hairs then ex- panding upon the surface film and preventing the water from flooding the chamber and interfering with respiration. When the larva de- scends below the surface the hairs are drawn inward, enclosing a large air-bubble which is carried in this manner until nearly exhausted, when the larva again ascends to the surface. The terrestrial forms lack the plumose hairs bordering the anal respiratory chamber and the latter is in some genera located upon the disc of the segment some distance before the apex instead of at the extreme apex as in the aquatic forms. No other species in Orthorrhapha known to me, except a few in Cecidomyiidae, transform:to the pupal stage within the larval, skin, and because of this peculiarity it will only be necessary to give a key to the larvae in the family. I have mainly used material in the Laboratory collection in drawing up the keys presented, but in a few cases I have also made use of published descriptions or borrowed ma- terial. : CHARACTERS OF THE FAMILY Larvae and Puparia—Twelve-segmented exclusive of the head, the latter attached at middle to first thoracic segment, and usually with a distinct ocular prominence on each side at varying distances trom front margin and numerous long hairs on dorsum and venter ; antennae distinct ; pseudopods absent, penultimate and antepenultimate segments sometimes armed with locomotor hooks on caudal margin of ventral surface; anterior spiracles near posterior margin of side of first segment ; lateral metathoracic and abdominal spiracles present or absent; posterior spiracles separated, located in a transverse slit- like cavity which may be apical or preapical and fringed with long plumose hairs or unfringed; entire surface of body finely shagreened. 316 HABITS OF LARVAE The aquatic larvae feed upon algae, decaying vegetable matter; and small Crustacea. The terrestrial species occur in a variety of situations, some of them being found in nests of Hymenoptera, or in those of rodents—where they act as scavengers; others occuring under loose bark of living or recently felled trees, feeding upon the sap, or on dipterous larvae; while still others feed upon decaying vegetation or on manure. One genus (Hermetia) has been recorded as feeding upon the dead body of a man. HABITS OF IMAGINES The species are most active on sunshiny days, some of them being much given to settling upon leaves of trees which are in full sunlight. Most species frequent flowers, especially those of Umbelliferae, feed- ing upon the nectar, and are particularly numerous on marshy ground or along the margins of streams, ponds, or other bodies of fresh water. Few species occur on the seashore and I know of none that that are found in the larval stage in salt water. The eggs are usually laid in masses on the leaves of aquatic plants, as shown in Figure 4, Plate XLVII. Kry To SUBFAMILIES LARVAE AND PUPARIA _1. Apical abdominal segment very much longer than broad and very distinetly tapered, but if the length is not over 3 times that of the basal width the antepenultimate and penultimate ventral segments have each 2 or 4 stout curved thorns on their posterior margins; posterior spiracular chamber at apex of last segment, the margin armed with numerous soft, plumose or pubescent hairs*"aquatie species: saen+ eee eee STRATIOMYIINAE (p. 317). — Apical abdominal segment not over twice as long as its basal width; if the species is aquatic and has the posterior spiracular chamber armed with marginal hairs the ventral thorns are absent...... 2 2. Aquatic species; bristles on dorsum paired, very short, sometimes thickened apically; posterior spiracular chamber margined with long, soft, plumose or pubescent hairs.............-00-eeeeees suf ov Naue roibs tale “sprays Sbotegeneiavome ee mbatc keen teatte CLITELLARIINAE, pt. (p. 322). — Terrestrial species; bristles on dorsum single, long and tapered, or in groups; posterior spiracular chamber on dorsum of apical seg- ment, transverse, not margined with soft hairs..............-. 3 3. Each segment with a deep notch in each lateral margin slightly be- fore middle, dividing the segment into 2 unequal lateral lobes (Fd i. DUD aL) aia ei eo Genus incertus 1 (p. 344). 317 Seements wit houtplateral NOEL. avers alalaye wis = «lsieyeusie #12 2\si0) epejaisisie-s 4 Bristles on dorsum very short, arranged in groups of 3-4; lateral bristles arranged similarly, two such groups on each side of each CELI By odes One Boe boo SeoDne oO aCmrEe BERIDINAE (p. 331). — Bristles on dorsum and lateral margins long, not in groups....... 5 Head much elongated, the portion anterior to eyes distinctly longer than its greatest width; antennae of moderate length, apical por- tion slender; the 6 conspicuous hairs on dorsal surface of thoracic and abdominal segments not in an almost straight transverse series, the median pair close to anterior margin and very much longer and stronger than the 2 lateral pairs, which are close to posterior margin; thorax and abdomen without long decumbent AIICS yet ete acetal ee er ee a iT a cea Povar snes Genus incertus 2 (p. 345). — Head not much elongated, the portion anterior to eyes about as long as its greatest width; or if the head is elongated the hairs on ab- domen are in straight or almost straight transverse series...... 6 6. Very large robust species, over 18 mm. in length; antennae of mod- erate length, apical portion stout; eyes moderately prominent; head distinctly narrowed immediately behind eyes, almost paral- lel-sided ; thoracic and abdominal segments densely covered with decumbent lanceolate hairs................-. CLITELLARIINAE, pt. — Smaller species, 10-12 mm. in length at most; antennae very small; BY. CSEVELVa sr OMMINEN tse acre witeciaiels leans lop sisus iene si a.eide n'y Seino avelelese ff Thoracic segments 1 and 2 each with a smooth plate on dorsum; apical segment with a transverse series of short teeth near base on ventral surface which are directed caudad................. PEIN Re ate c trot shai se, wits fas of eiakenesinjal a ahs lige 04s XYLOMYONAE (p. 340). — Thoracic segments without smooth plate on dorsum............. 8 8. Bristles slightly clubbed with the exception of some of those on head and those on apical segment...... Genus incertus 3 (p. 345). — Bristles tapered to a point, not clubbed...................2005. 9 9. Robust species; dorsum distinctly striate; head short and broad... MET Tats oterofeveser ere eet ee he oe ai svar ele gfers site 2PateTs GEOSARGINAE (p. 331). — Slender species; dorsum unicolorous, brown or testaceous; head long BNOESIONC Cle orait tase c.s.e 2 oats eedsie evntevers PACHYGASTERINAE (p. 334). me 1 | Subfamily STRATIOMYIINAE SUBFAMILY CHARACTERS Larva and Puparium.—Head elongate, armed as in Figures'1 and 2, Plate XLVIII; antennae well developed; maxillae very elaborate, the palpi well developed; mandibles weakly chitinized, the teeth slen- der. Body with rather weak armature, sometimes with scale-like hairs on dorsum, and in Odontomyia with strong thorns (2 or 4) on posterior margin of penultimate, or of both penultimate and ante- 318 penultimate, ventral segments; lateral abdominal spiracles indis- tinguishable; apical segment much elongated; the apical 3 or 4 seg-> ments tapered posteriorly in Stratiomyia; posterior spiracular cham- ber in apex of last segment, fringed with long soft hairs. Imago.—Third antennal joint without a differentiated arista; abdomen with 5 or 6 visible segments; 4 posterior veins in wing be- tween apex of third vein and apex of second branch of cubitus, the first cubital branch arising from the second basal cell. HABITS OF LARVAE The larvae are aquatic, their food consisting of algae, decaying vegetable matter, and minute organisms such as crustaceans. HABITS OF IMAGINES The flies are invariably flower-frequenters, occurring in large numbers on Umbelliferae, etc. Kry To GENERA LARVAE AND PUPARIA 1. Apical abdominal segment very much elongated, more than 3 times as long as its greatest width; penultimate and antepenultimate ventral segments without curved thorns; antennae about three times as long as their diameter.................... Stratiomyia. — Apical abdominal segment at most 3 times as long as its basal width; penultimate and antepenultimate ventral segments, or only the former, with 2 or 4 strong curved thorns on their posterior mar- gins; antennae about 6 times as long as their diameter.......... Pie eve apetehena Ste aha Sidseeat o OMOnci ee eR te ee. el ee eke eee Odontomyia. STRATIOMYIA Geoffroy GENERIC CHARACTERS Larva and Puparium (Pl. XLVII, Fig. 1).—Elongate, slightly tapering anteriorly; the head elongate, antennae short. Posteriorly the body is usually much attenuated, the last segment being more than 3 times as long as its greatest width; no curved thorns on ven- tral segments; dorsum with or without surface hairs, but without the well-defined transverse series of 6 bristles so noticeable in Geosarginae and Pachygasterinae, and without curved thorns on posterior margin of antepenultimate and penultimate segments ventrally. 319 Imago.—Robust, black species, with conspicuous yellow, greenish, or whitish markings. Abdomen with 5 or 6 visible segments; third antennal joint without a differentiated arista; 4 posterior veins pres- ent on wing, 3 of which arise from discal cell; third vein forked; scutellum spinose; basal joint of antennae at least 3 times as long as second. HABITS OF LARVAE The larvae are aquatic, occurring in ponds and_ slow-flowing streams. ‘Their food consists of decaying vegetation and minute organisms—such as algae, diatoms, and crustaceans. Species that I have kept in the laboratory fed upon decaying leaves, eating all but the veins and main ribs. ‘The skin of the larvae is very tough and, except just after molting, covered with a sedimentary deposit which serves to conceal the species on the mud bottoms where they occur. They become conspicuous, however, when they crawl out of the water on the muddy banks, as their skins dry out rapidly and become gray- ish, so that they are readily seen against the darker ground. The larvae stand drying out remarkably, some of those I had recovering upon being placed in water even after they appeared to be hard and lifeless. This faculty of recovery must prove of great value to the species which occur in shallow ponds or in streams which dry up dur- ing periods of summer drought. HABITS OF IMAGINES The flies are usually found on flowers of various plants, and are particularly common upon wild parsnip and wild carrot. Key To LARVAE AND PUPARIA 1. Prothorax with slender hairs on its anterior margin; apical segment about 6 times as long as its basal width................. norma. — Prothorax with a number of short, stout processes on its anterior margin in addition to the slender hairs; apical segment about 3 fames:as long as its basal width. .4 0.2.5... fcsti ee shaw meigent. STRATIOMYIA NORMA Wiedemann Stratiomyia norma Wiedemann, Aussereur. Zweifl. Ins., Vol. 1, p. 62. (1828) Larva (Pl. XLVII, Fig. 1).—Length, 30-40 mm.; greatest diameter, 5.6 mm. Dorsum with 6 indistinct pale vittae and pale spots at bases of the slender surface hairs, lateral margins pale. 320 Head as in Figures 1 and 2, Plate XL,VIII, the antenna not over 3 times as long as its apical diameter (Fig. 6, a) ; maxillae very com- ~ plex (Fig. 3) in life, moving rapidly and alternately with an upward and downward motion; mandibles weak (Fig. 6). Entire body with rather long weak hairs, a pair on lateral margins, and 6, stronger than the others, in a transverse series on disc of each segment; apical segment about 6 times as long as its basal width, the terminal hairs of moderate length. The foregoing description was made from material obtained in the Illinois River and used by Mr. Hart in connection with his paper previously referred to. The species is very common in the Illinois and connected rivers and streams. For a more complete description of the external appearance of the larva and details of the life history of the species the reader is re- ferred to Mr. Hart’s paper.* STRATIOMYIA MEIGENI Wiedemann Stratiomyia meigeni Wiedemann, Aussereur. Zweifl. Ins., Vol. 1, p. 61. (1828) Larva.—Length, 25 mm.; greatest width, 5 mm. Darker than the preceding species, the pale vittae distinct only at posterior margin of each segment. Differs from norma in having a number of short, stout processes on anterior margin of dorsum of first segment, and in the length of the apical segment—which is but little more than 3 times as long as its basal width and more gradually tapered than in norma. Described from specimens obtained in a small stream at Muncie, Ill., in April and May, 1916. I had many larvae but reared only 2 imagines. The species is very common throughout the state, and the imago has been previously recorded by Mr. Hart, under the name marginalis Loew, from Bureau, Rock Island, McLean, and Champaign counties. It occurs commonly on flowers of wild parsnip in August at White Heath, Urbana, and Muncie. Opontomyia Meigen Larva and Puparium (Pl. XLVIUL, Figs. 2, 3).—Similar in general appearance to Stratiomuyyia, but differs in the following particulars: the antennae are longer—about 6 times as long as their apical width; the apical segment is not more than 3 times as long as its basal width *Bull. Ill. State Lab. Nat. Hist., Vol. 4, Art. VI, pp. 248-252. (1895) 321 and but slightly tapered; and the penultimate segment—sometimes the antepenultimate also—bears 2 or 4 curved thorns on the posterior margin of the ventral surface. HABITS OF LARVAE The larvae are aquatic, living in streams, particularly in those with slow current and muddy bottom. Their food consists of algae, small crustaceans, and decaying vegetable matter. HABITS OF IMAGINES The flies are commonly found on flowers along the margins or in the immediate vicinity of streams. Key To LARVAE 1. Dorsum with 6 pale vittae, which are usually so close together as to give the appearance of a single longitudinal band that tapers posteriorly ; large species, 20-30 mm. in length.......... cincta. — Dorsum with 6 pale vittae which are rather widely separated and do not form a longitudinal pale band; smaller species, 12-15 mm. PIL ETE OCG Hever ees Pein fae eeu sac accep ey Secs, cveysksy 2) oxen seep ua 'sr) mys vertebrata. OpONTOMYIA CINCTA Olivier Odontomyia cincta Olivier, Encycl. Méth., Vol. 8, p. 432. (1811) Odontomyia extremis Day, Proc. Acad. Nat. Sci. Phila., 1882, p. 80. The larva (Pl. XLVI, Fig. 3) of this species has been described by Mr. Hart*. I have dissected the head and find that the maxillae and mandibles differ from those of Stratomyia norma as shown in Figures 3 and 6 and 5 and 7, Plate XLVIII. The larvae may also be distinguished from Stratiomyia as indicated in the key to genera. The species is represented in our collection by many larvae, mostly obtained in the Illinois River. Most of the imagines were taken in the vicinity of the Sangamon and Illinois rivers, but a few were ob- tained at Muncie, near some small streams where the larvae were found. ODONTOMYIA VERTEBRATA Say Odontomyia vertebrata Say, Appendix to Vol. 2 of Keating’s Narrative of an Expedition to the Source of St. Peter’s River, ete., p. 369. (1824) *Bull. Ill. State Lab. Nat. Hist., Vol. 4, Art. VI, pp. 260-261. This species occurs generally throughout the state, and in fact in most parts of North America. The larva (Pl. XLVII, Fig. 2) is found in rivers and small streams, and differs from that of cincta in its smaller size and in the markings, as stated in key. For fuller de- scriptions and life histories of the two species see Mr. Hart’s paper previously cited. I have found the larvae abundant in a small stream at Muncie from April to June. Subfamily CLITELLARIINAE This subfamily does not, in my opinion, form a natural group. I consider that Hermetia does not properly belong with the aquatic forms, being more closely allied to Geosarginae in larval characters, but I leave the arrangement as in Williston’s “Manual” pending fur- ther information upon the life history of other genera. SUBFAMILY: CHARACTERS Larva and Puparium.—The larvae of the aquatic forms differ from those of Stratiomyiinae in having the apical segment compara- . tively shorter, almost subquadrate, and the dorsum with short thick bristles arranged in a transverse series near posterior margin of each segment except the apical. The genus Hermetia is terrestrial, re- sembles the larva of Geosargus in many respects (though much larger than any species of that genus known to me), and has the body slight- ly broadened apically, the dorsum unicolorous, and the head long and tapered anteriorly. Kry To GENERA LARVAE AND PUPARIA 1. Terrestrial species; body not tapered posteriorly; apical segment rounded ; opening of the posterior spiracular chamber in the form of an unfringed transverse slit at apex of dorsum of last segment Sa E EE ok oe hole Gal oraue lode e eeekone Chon at Gre Meee ot eer Lenore ae Hermetia. — Aquatic species; body tapered anteriorly and posteriorly; apical segment elongated and more or less truneated; opening of posterior spiracular chamber fringed with soft hairs........... 2 2. Posterior spiracular chamber situated on dorsum of apical segment, the fringe of hairs rather short; apical segment armed with 4 lone" mareimnalGhairs cn sso creel eile eee eee: Nemotelus. — Posterior spiracular chamber at apex of apical segment, the fringe of hairs long; apical segment without the long marginal hairs... TARE er ci mm mnt Som boketu esha ache ns Oxycera. 323 HERMETIA Latreille I have before me one larva and several puparia of a species. of this genus. It is probable that the generalization given below will apply to all species of the genus. GENERIC CHARACTERS Larva and Puparium.—Head long, tapered anteriorly; antennae distinct but short, rather slender. Body broad, of nearly uniform width except apically, where it becomes slightly broader; surface with many short hairs, and a number of long bristles in almost straight transverse series; lateral bristles long, simple; apical segment very similar to that of Geosargus, the marginal bristles long; respiratory chamber terminal. Abdomen with distinct lateral spiracles on seg- ments I—7. HERMETIA ILLUCENS Linné Musca illucens Linné, Syst. Natur., ed. 10, Vol. 2, p. 979. (1758) Larva and Puparium (Pl. XLVIII, Fig. 13).—Length, 16-18 mm.; greatest width, 5 mm. Dark brown, head yellowish, dorsum unstriped. Head long and rather narrow, the surface hairs short, arranged on dorsum as in Figure 10, Plate XLVIII; antennae short and stout, apical joint about as long as basal but much thinner. Body covered | with fine short hairs and with long bristles arranged as in Figure 10; spiracles on prothorax much larger than the lateral abdominals; only 2 long bristles on sides of each thoracic segment when seen from above. Abdomen becoming broader posteriorly ; spiracles distinct on segments I-7, segments 2—5 with a small round wart just posterior to each spiracle; apical segment longer than preapical, armature of venter as in Figure 11; respiratory chamber terminal. Described from specimens sent me by L. H. Dunn—which were found in 1915 feeding upon the dead body of a man ina jungle about three miles from one of the settlements in the Panama Canal Zone— and one specimen taken by C. A. Hart at Galveston, Texas. Under the name H. mucens, Riley and Howard recorded the larvae as living upon wax, etc., in beehives* ; and larvae supposed to belong to this species are recorded by Morgany as occurring in the alimentary canal of man. He also states that they have been found *Insect Life, Vol. 1, 1899, p. 353. tBull. 48, sec. ser., Louisiana Agr. Exper. Station, p. 151. (1897) 324 in catsup and decaying vegetables and reared from potatoes. The larvae are numerous in privies in the Southern States and in Central America. NeEmoreELus Geoffroy I have not seen the larva of any species of this genus. Lundbeck* has described and figured the larva of the European pantherina, which agrees in general characters with wliginosus, also of Europe, previous- ly described by Halidayj. The characters that serve to separate the larvae of Nemotelus from those of Oxycera are given in the key to the larvae of this subfamily (Clitellarinae). The larvae are aquatic, and although unknown to me must be common in suitable situations throughout the state, since in the imaginal stage at least one species commonly occurs from June to August on various flowers. OxycERA Meigen GENERIC CHARACTERS Larva and Puparium.—t have found only one larva that I con- sidered as belonging to this genus, and unfortunately it was not pre- served when it died. Lundbeck’s description of the larva of trilineata is the best available, and the following data are drawn from his paper.£ Head conical, with small eye-spots on the anterior part and small antennae anterior to them. Segments broader than long, only the apical one a little longer than broad, rounded behind. Dorsum with stout bristles which are thickened apically, arranged in pairs, 2 pairs on each side of median line, the median pairs close together, and in addition to these bristles, which are near the posterior margin, sev- eral appear laterad of them and also a transverse series of much shorter bristles near anterior margin; lateral margins with a pair of strong bristles on each segment, including the apical one. Posterior spiracular chamber at apex, fringed with long hairs; abdominal seg- ments I to 6 with rudimentary lateral spiracles. *Diptera Danica, Part I, p. 23. (1907) tNat. Hist. Rev., No. III, 1857, p. 194. {Diptera Danica, Part I, p. 31. (1907) 325 HABITS OF LARVAE The larvae are aquatic, occurring along with and having the same habits as those of Stratiomyia and Odontomyia. HABITS OF IMAGINES The flies are rarely taken except by sweeping amongst vegetation on the margins of streams or ponds, or on marshy ground. I have not found them on flowers. One species I have taken in numbers on the leaves of bracken (Pteris) in Europe. As there is no synopsis of the species of this genus for North America the following key and revision is presented as an aid to students. Key To SPECIES IMAGINES 1. Thorax with 2 yellow lines on dorsum in addition to the pair on upper margins of pleurae....... APs tiers easlelasneicte, Sala sw eevee tele 2 — Thorax with 4 yellow lines on dorsum in addition to the pair on MDPELaMaAn ons Ot mOleUTAC hers sew bleed vie eicle cia) siere Seine aie gielomere 3 PeHEMOLA MN Part DIACK .6's0 oe.c.00s00016 whe s's,00,000 98 «0 centralis (p. 326). — ‘Femora entirely yellow................... approximata (p. 326). 3. Abdomen with a complete yellow fascia on third segment in addi- tion to the usual lateral spots............... variegata (p. 327). ~ -— Abdomen with at most 3 spots on third segment, one in center and OMOMONMCACDESIMON pre me mia si eret ta cin sfalaereleisinie ooine s/mid ait alslowere 4 4. Central spot absent from third abdominal segment; legs with black markings; large species, 8 mm................- crotchi (p. 328). — Central spot present on third abdominal segment; legs, with the ex- ception of the coxae, yellow; smaller species, about 5 mm...... 5 5. Fourth abdominal segment with 2 small spots on center, the lateral pale marks very distinctly curved forward and widely separated ; veins surrounding discal cell of wing distinct. .aldrichi (p. 329). — Fourth abdominal segment without spots except the laterals; veins euclosine discal cell amdistinet:. aie. lee «20.4 50 «2 «2 's.00's 0 +0 5,0 6 6. The pale markings whitish ; lateral stripes on frons very slightly in- curved at upper extremity, not connected there (female)....... 5 Shon Oba J 4A ASS CREE Ee GER a anne albovittata (p. 380). — The pale markings sulphur- or lemon-yellow; lateral stripes on frons distinctly incurved and connected with each other at their upper extremities (female)...................%. picta (p. 331). 326 OXYCERA CENTRALIS Loew Oxycera centralis Loew, Berl. Ent. Zeitschr., Vol. 7, 1863, p. 8. This species is somewhat similar to approximata, differing in hav- ing the antennae black, the pleurae immaculate, and the legs, especially the femora, with black markings. Originally described from Red River of the North, and not sub- sequently recorded as far as I am aware. OXYCERA APPROXIMATA, Nn. Sp. Male.—Glossy black, with lemon-yellow markings. Head black, sides of frons with a silvery line which is connected with one on sides of face, the latter becoming abruptly narrowed on its lower third; mouth parts yellow; posterior eye-orbits silvery; antennae orange, apical joint (6th) and arista brown. ‘Thorax with 2 yellow vittae near lateral margin which extend from humeral spot to suture and slightly beyond, and are occasionally connected with a large’ irregular spot on posterior lateral angles of disc; another yellow line, connected with the sublateral one by the humeral spot, extends along the upper margin of pleurae to wing-base, where it becomes conspicuously broader; below the expanded posterior portion of the lateral line is a large yellow spot, and slightly caudad of the latter and situated high- er on the side is a smaller one; scutellum black, margin narrowly yel- low, thorns yellow, blackened at apices. Base of abdomen with a yel- low spot which extends laterad anteriorly in the form of a slender line; third segment with a pair of approximate spots on anterior half and an oblong spot on postero-lateral angle; fourth segment with an oblong spot on postero-lateral angle which is smaller than that on the preceding segment; fifth segment with the posterior margin rather broadly yellow; lateral spots usually carried more or less distinctly along the extreme lateral margins of segments; venter black. Legs yellow; coxae black. Wings clear, veins yellowish. Halteres lemon- yellow. Eyes contiguous; antennae rather short, not longer than arista. Thorax with short brownish discal hairs; scutellar thorns of normal size. Abdomen with rather sparse short pale hairs. Legs normal in structure. Cross vein furcate, the fork forming almost a right angle; the 4 veins leaving discal cell indistinct. Female.—Differs from the male in having the 2 approximated spots on third abdominal segment smaller and separated, and in the color and structure of the head as follows: frons one third the width 327 of head, glossy black, a conspicuous yellow line on each side extending from base of antennae somewhat above middle of frons, its upper portion being separated from the eye-margin by a narrow black line; face glossy black, slightly yellowish on each side, and with a con- spicuous silvery, pilose, stripe which extends beyond the lower extrem- ity of the yellow line on frons; posterior eye- -orbits conspicuously yel- low. In other respects as in the male. Length, 5 mm. Type locality, Muncie, Illinois, July 5, 1914 (J. R. Malloch). Allotype (male), Lafayette, Indiana, June 23 (J. M. Aldrich). The type specimen was taken by sweeping vegetation on the bank of Stony Creek. The allotype is in the collection of Prof. J. M. Al- drich; the type, in the collection of the Illinois State Laboratory of Natural History. This species is closer in general appearance to centralis Loew than to any described North American species, but may be readily separated from it by the entirely yellow legs, the greater amount of black on scutellum, and the presence of pleural oe as well as by other charac- ters.. OXYCERA VARIEGATA Latreille Oxycera variegata Latreille, Encycl. Méth., Vol. 8, p. 600. (1811) Oxycera variegata (Olivier) Macquart, Dipt. Exot., Vol. 1, Pt. II, p. 191. (1838) Oxycera unifasciata Loew, Berl.-Ent. Zeitschr., Vol. 7, 1863, p. 9. Male.—Black, shining, with conspicuous lemon-yellow marks. Head black; frons with a lateral line of white pilosity which connects with a similar line on sides of face, the latter abruptly narrowed on lower portion; face with 2 yellow spots below bases of antennae; mouth parts yellow; antennae reddish yellow, apical joint (6th) and arista brownish; occiput and anterior eye-orbits black. ‘Thoracic vittae yellow, 4 in number, submedian pair slightly dilated anteriorly, and with a perceptible outward curve, occasionally connected with the sublateral pair, interrupted at suture, the portion beyond suture subtriangular and extending to posterior margin of disc; sublateral vittae broader than submedian pair, slightly dilated anteriorly, at suture, and posteriorly, connected with lateral stripe by humeral spot; pleurae with 2 spots on posterior portion; scutellum black only on extreme anterior margin and apices of thorns. Abdomen black; a large oblong spot on base of dorsum, a small lateral spot on sides of second segment, a complete fascia (which is slightly emarginate on posterior margin) on third segment, a large oblong spot on fourth 328 segment, and the greater portion of fifth segment yellow, these mark- - ings being connected by means of a narrow yellow marginal line; venter with a conspicuous oblong yellow spot on lateral margins of each segment. Coxae black, legs yellow. Halteres yellow. Eyes contiguous; antennae short, barely longer than arista. Thoracic hairs yellow, particularly noticeable on anterior central por- tion; scutellum shorter than the thorns. Legs normal. Fork of third vein at right angles to that vein; the 4 veins leaving discal cell indis- tinct. Female.—Differs from the male in the color and-structure of the head as follows: frons glossy black, about one third the head-width, almost parallel-sided, in profile distinctly higher than eyes, a more or less distinct suture or depression visible on center, a rather broad yel- low line on each side, extending from a short distance above the antennae to the anterior ocellus, dilated at its lower extremity, where it almost touches the eye-margin, of nearly uniform width through- out the remainder of its length, and separated from the eye-margin by a space equal to its own width, the space between slightly in- creased at the upper extremity; face as in male but the yellow spots larger; posterior eye-orbits yellow, blackened slightly below and sep- arated from the large yellow vertical spot by a narrow black line. In other respects as the male. Length, 3.5—4 mm. Originally described from Carolina. Loew described the same species, under the name wnifasciata, from Pennsylvania. Melander has recorded wnifasciata from Virginia and Illinois. I have seen specimens from Monticello, Illinois (Hart and Malloch) and Lafay- ette, Indiana (J. M. Aldrich), taken in June and July. OxyYcCERA CRoTCHI Osten Sacken Oxycera crotchi Osten Sacken, Western Diptera, p. 212. (1877) Original description: “Oxycera crotchi n. sp., ?.—Abdomen with three lateral yellow spots on each side and an apical triangular one, all connected by a narrow yellow margin; femora black, with yellow tip; tibia and tarsi yellow. Length 8 mm. “Female.—F ace and front yellow, with a broad black stripe in the middle; posterior orbits yellow; vertex, cheeks under the eyes, and occiput black. Antennze: basal joints black (the rest wanting). Thorax black, opaque; a yellow stripe from the humerus to the ante- scutellar callus is interrupted a little beyond the middle, a pair of nar- 329 rower yellow stripes on the dorsum slightly expanded in front and not reaching beyond the transverse suture; scutellum yellow, the base black; pleurz with a large yellow spot in front of the wings, and a smaller oblong one under it; the black opaque abdomen has a sub- triangular yellow spot on each side of the second segment, a larger, semi-elliptical spot on each side of the third segment, a somewhat similar, but smaller, pair of spots on the fourth segment, a large tri- angular spot on the last segment; all these spots are connected by the narrow, yellow, abdominal margin; ventral segments yellow in the middle, brownish black on the sides. Femora black with yellow tips; tibiz and tarsi yellow; joints 3 or 4 of front tarsi darker. Wings tinged with yellowish anteriorly, with grayish posteriorly; stouter veins and stigma reddish yellow. “Hab.—California (G. R. Crotch). A single specimen.” This species may belong to the genus Euparyphus; the third joint of the antennae—the best character for the separation of the genera— was missing from the type. I have not seen any specimens either of Oxycera or Euparyphus that agree entirely with Osten Sacken’s de- scription, though two males of a species of Euparyphus in Professor Aldrich’s collection from Idaho and Colorado agree fairly well with it. The submedian yellow thoracic vittae do not extend much beyond the suture in these specimens, but the third vein is unforked—a charac- ter that it is improbable Osten Sacken would overlook. The length given for crotchi, 8 mm., exceeds that of any other member of the genus Oxycera from North America. Originally described from California and not subsequently re- corded. OXYCERA ALDRICHI, n. sp. Male.—Black, shining, with lemon-yellow markings. Head black; face with a white pollinose line on lateral margins which extends along the sides of frons, and 2 yellow spots below bases of antennae; antennae apically brown; mouth parts yellow. Thorax with the same yellow markings as in variegata. Abdomen with the following yel- low markings: a large basal spot which is slightly narrowed posterior- ly, a larger similarly shaped transverse spot on middle of third seg- ment, a pair of minute rounded submedian spots on fourth segment, a large subtriangular spot on fifth, a small lateral spot on second, a large anteriorly curved one on lateral margins of third and a nar- rower similarly curved one on fourth; venter black, the lateral mar- gins yellow. Coxae black, legs reddish yellow. Wings clear, veins yellow. Halteres lemon-yellow, stems reddish. 330 Structurally as the male of variegata, but the veins enclosing the- discal cell are much more distinct. Length, 4.5 mm. Type locality, Lafayette, Indiana, June 23 (J. M. Aldrich). Named in honor of the collector. OXYCERA ALBOVITTATA, Nl. Sp. Female.—Black, shining, with conspicuous whitish markings. Head black; frons with a white line on each side from anterior ocellus to antennae, touching the eye-margin on the lower third and separated from it on the upper two thirds by a space subequal to its own width, not incurved above, connected with the white, pilose lateral face-stripe at base of antennae, the latter not abruptly narrowed be- low, gradually tapering; face with the exception of the lateral lines black; posterior orbits white, except a portion along eye-margins on upper half, separated from the white spot on vertex by a narrow black line; mouth parts whitish yellow; antennae reddish, basal two joints whitish, apical joint brown. Thorax with the same pale markings as variegata; base of scutellum and basal angles black. Abdomen with the following creamy white markings: a transverse spot at base, pro- duced caudad in center, a moderately large oblong spot on center of third segment which is rounded posteriorly, the entire apical half of fifth segment, and a spot on lateral margins of second, third, and fourth segments, all of the marginal spots connected by means of the narrow marginal whitish line, the spot on each side of third segment larger than the others; venter black, marginal spots showing slightly. Coxae black, legs flavous. Wings clear, veins yellow. Knob of halteres white, stem brownish. Hairs on body whitish. Frons slightly broader than eye-width, slightly raised on each side of the median line, this line and the lateral edges slightly impressed ; antennae rather elongate, arista not longer than the composite third segment (3-6); posterior orbits rather broad. Thorax distinctly punctured, discal hairs rather short. Abdomen and legs of normal form. Vein closing apex of discal cell in vertical line with apex of stigma; the portion of costa from apex of stigma to fork of third vein distinctly longer than that from fork of third vein to apex of third. Length, 5 mm. Type locality, Muncie, Illinois, July 5, 1914 (J. R. Malloch). 331 Oxycera picta Van der Wulp Oxycera picta Van der Wulp, Tijdschr. v. Entom., Vol. 10, 1867, p. 133. A male which I believe belongs to this species differs from the foregoing description in having the pale markings lemon-yellow and considerably larger. The antennae are shorter, not exceeding the length of the arista, and the entire length of the specimen is 5.5 mm. Locality, Urbana, Illinois, June 7, 1901 (C. A. Hart). Van der Wulp had some doubts as to the identity of his species with that described by Latreille as maculata, since many essential characters were not mentioned by that author, and Macquart in his redescription of the type did not make matters much better. From albovittata the female of picta may be separated by the sulphur- colored markings, and by the fact that the lateral frontal stripes curve inwards above and connect with each other and with a pale line round the ocelli. It is possible that Van der Wulp had two species mixed, as he says that there are sometimes 2 yellow spots below the an- tennae—a character that I am inclined to believe is not by any means variable, and one which is absent from the male described above. Picta was originally described from Wisconsin. Melander has re- corded maculata from Louisiana, but the record may refer to picta. Subfamily BERIDINAE I have not seen the larva of any species of this subfamily. My only information as to the characters of this stage is derived from European authors, and is included in the key to the subfamilies of Stratiomyiidae. The larvae are terrestrial in habit. In general appearance they resemble those of Geosargus, but differ in having the bristles on the dorsum and lateral margins short and closely placed in groups of 4 or more. The imagines are very rarely met with in North America—a fact quite in contrast with conditions in Europe, where several species are among the very commonest of any in the family. Subfamily GEOSARGINAE This subfamily contains nine distinguishable genera. Williston gives ten in his “Manual”, but there is no valid reason for separating Macrosargus from Geosargus. I have obtained the larvae of two genera, which are described herewith. 332 SUBFAMILY CHARACTERS Larva and Puparium.—Head elongate; antennae distinct but short. Body broad, almost parallel-sided, slightly narrowed anterior- ly, rounded posteriorly, with distinct vittae; segments distinct; dorsal segments with a transverse series of 6 strong bristles; lateral mar- gins of each segment except the apical one with 2 bristles; ventral segments with bristles similar to but weaker than dorsal series, spiracular chamber transverse, situated on disc of apical segment near apex; apical segment with a number of long marginal hairs and a few on disc. Imago.—Antennae short, with an apical or dorsal arista; abdomen with 5 or 6 visible segments; discal cell emitting 3 veins. Key To GENERA LARVAE 1. Pale stripes on dise of dorsal segments geniculated on each segment Sisde Syeiats ah sie se ayele ale Seis s/oaboteney apse eteune Scat ek TALL Geosargus. — Pale stripes on dise of dorsal segments straight....... Microchrysa. GEOoSARGUS Bezzi This genus is synonymous with Sargus of Aldrich’s Catalogue, Sargus Fabricius being preempted by Sargus Walberg. GENERIC CHARACTERS Larva and Puparium.—The larva differs from that of Micro- chrysa in the shape of the head, which is much shorter in comparison with its width than in that genus. Imago.—Brilliant metallic blue or green flies, with slender bodies and unspined scutellum. HABITS OF LARVAE The larvae are scavengers, feeding on decaying vegetation and manure. HABITS OF IMAGINES Commonly found on leaves of trees and bushes, especially if in the sunshine, and particularly on such trees or bushes as border pas- tures. One species, nubeculosus Zetterstedt, was introduced into North America from Europe. It has been recorded as feeding’in the larval stage on decaying turnips and other root-crops. 333 GEOSARGUS VIRIDIS Say Sargus viridis Say, Jour. Acad. Nat. Sci. Phila., Vol. 3, 1823, p. 87. Larva and Puparium (Pl. XLVIII, Fig. 16).—Length, 9 mm.; width across dorsum at middle, 3 mm. Brownish testaceous, dorsal surface with a dark grayish brown, slightly irregular, waved stripe on each side of the middle line, the area laterad of the line occupied by 2 rather less distinct stripes of the same color, which are slightly fused and irregular, the whole dorsum having the appearance of being six-striped, the median pair of stripes more or less distinctly connected near anterior margin of each segment and enclosing 2 small spots near posterior margin, the ventral surface similarly marked. Head with only 2 brown dorsal lines; tips of maxillary palpi, mandibles, and an- tennal base dark brown. Head slightly longer than broad, armed as in Figure 8, Plate XLVIII; surface of thoracic and abdominal segments finely sha- greened (Fig. 16, 0), the armature as shown in the same figure; spiracular depression in the form of a deep transverse slit, situated very close to apex of segment; ventral segments with armature similar to that of dorsal; apical ventral segment as in Figure 12. Described from examples obtained in cow manure at Muncie, IIl., in April, 1916. The larvae are very sluggish. The first example of the imago emerged in the laboratory a month after being brought in from the field. The species is common everywhere in Illinois, and in fact all over the United States. GEOSARGUS sp.? I have before me a number of larvae of a species of Geosargus that differ from viridis in having the head longer—more resembling that of Microchrysa polita—and also in the striping of the dorsum, the central dark stripe consisting of a series of diamond-shaped spots —one on each segment—instead of a divided stripe as in viridis. In other respects the larvae agree closely. I have a suspicion that the color of these specimens may not be that of fully matured larvae, as they had previously undergone very considerable changes, being whitish testaceous and without distinct vittae and almost devoid of bristles when young, developing the vittae and bristles as they matured. If they had overwintered safely they might have assumed the coloring and structure which would have proven them to be viridis, but as it is I can not definitely decide their specific status. 334 The species was obtained by me at White Heath, IIl., June 24, ~ 1916, from horse dung. Microcurysa Loew GENERIC CHARACTERS Larva and Puparium.—Very similar to the larva of Geosargus, differing as indicated in generic key, and in having a longer head. Imago.—Brilliant metallic blue species, with rather stout bodies. HABITS OF LARVAE The larvae feed upon manure or decaying vegetation. The species hibernate as larvae. HABITS OF IMAGINES The flies have similar habits to those of Geosargus. Microcurysa PoLrita Linné Musca polita Linné, Fauna Suecica. (1761) Larva and Puparium.—Length, 5-6 mm. Differs from Geosargus viridis in having the two pale stripes on dorsum entirely straight and the central dark line complete. Head more slender anteriorly than in G. viridis (Pl. XLIX, Fig. 2). Armature similar to that of viridis except that the bristles are much longer. Apical segment more attenuated apically than in Geosargus, the respiratory opening much smaller, not in the form of a transversely elongated slit, and farther from apex than in that genus (PE XIX Pigs 3) Described from specimens from which imagines were obtained by the writer. The larvae were found in company with those of Geosargus viridis in cow manure at Muncie, Ill., in April, 1916. They closely resemble the larva of Geosargus, but the difference in the dorsal markings readily separates the two. The imagines are not nearly so common as those of Geosargus viridis. Subfamily PACH YGASTERINAE I recently published a revision of the imagines of this subfamily*, and students may refer to that for full information regarding species. *Ann. Ent. Soc. Amer., Vol. 8, 1915, pp. 305-320. 335 The present paper deals only with the early stages and additional data bearing upon the occurrence of Illinois species. SUBFAMILY CHARACTERS Larva and Puparium.—Very similar in general appearance to the larvae of Geosarginae; but all species that I have seen, differ in hav- ing no distinct color-markings on dorsum, the body being uni- formly testaceous or brownish. ‘The head is also noticeably more elongated and the body narrower in comparison with its length. The armature of the body varies throughout the subfamily, but the bristles are always conspicuous—though sometimes of unequal length—the surface is shagreened as in other subfamilies, and there are no evi- dent decumbent hairs. The apical segment is similar to that of Geosarginae. ‘he lateral abdominal spiracles are very small, or in- distinguishable. Key TO GENERA LARVAE AND PUPARIA 1. Abdominal bristles very long, those on lateral margins, and on pos- terior margin of apical segment particularly so, the latter of uni- form length and as long as or nearly as long as width of seg- — Abdominal bristles short, those on margin of apical segment not more than half as long as width of segment, some of them very SINGS cca yatd 3/5 CSHE. CO Ore rN Cae ORE aie PO aon Cae ee Neopachygaster. Outer bristle of each transverse series on dorsal abdominal seg- ments minute, not more than a sixth as long as next bristle, the latter very much longer than inner pair......... Eupachygaster. — Outer bristle of each transverse series on dorsal abdominal segments about half as long as next bristle, the latter not very much longer itpeara aA TNT) Clin DOSE) Rete Stave aware, Mase ckt gas suc ve js hews.Seehe, whe, 72 ei ect Zabrachia. i) NEOPACHYGASTER Austen I have before me a large series of larvae and empty puparia of maculicornis Hine, the only species in North America so far assigned to this genus. GENERIC CHARACTERS Larva and Puparium.—Head very much longer than its greatest width, much tapered anteriorly; antennae very short; surface hairs long. Body narrower than in Zabrachia and Eupachygaster, the bristles comparatively shorter. 336 NEOPACHYGASTER MACULICORNIS Hine Pachygaster maculicornis Hine, Ohio Nat., Vol. 2, 1902, p. 228. Larva and Puparium.—Length, 3-4 mm. Pale testaceous, un- inarked. Head similar to that of Eupachygaster henshawi in general ap- pearance, the bristles noticeably shorter. Armature of body similar in arrangement to that of henshawi but the bristles much shorter, their relative lengths on penultimate and ultimate _ Segments as in Figure 6, Plate XLIX. The larvae of which the foregoing is a brief declanen were ob- tained under the bark of fallen elm-trees at White Heath, Ill, in March and April, 1916. I reared a large number of imagines from the larvae, and have also many of the latter alive in the laboratory now (January, 1917) which I took under similar conditions in the forestry of the University of Illinois October 21 and 28, 1916. The larvae feed upon decaying matter under the slightly loosened bark, but also, occasionally, on other dipterous larvae—as on those of Lonchaea polita, which are found along with them. Lonchaea larvae often eat other larvae and puparia—as do also those of Eusxesta, which frequents the same habitat—in fact the dipterous larvae found under bark under conditions suitable for Stratiomyiidae appear to be almost without exception alternately predaceous or saprophagous. They may be able to live entirely upon the sap and slightly decayed vegetable matter under the bark but I suspect that the main food sup- ply consists of excreta, exuvia, or the bodies of coleopterous larvae that occur there. That they feed upon each other I have proven by personal observation. EupPACHYGASTER Kertész I obtained a single larva of this genus under the loose bark of an apple-tree at Savoy, Ill., May 4, 1916, from which I succeeded in rearing a female imago. A comparison of the larva when found with a figure of that of Eupachygaster tarsalis Zetterstedt convinced me that I had one that was congeneric with that species, and as I had provisionally placed but one North American species in that genus I was particularly anxious to discover whether my diagnosis of the imagines was correct. I was therefore much gratified to find that the resultant imago agreed generically with the species I had placed in this genus. I subsequently obtained many larvae of the genus at Urbana, most of which are still alive (January 1917). 3387 GENERIC CHARACTERS Larva.—Head elongate, tapering anteriorly, the portion anterior to eyes distinctly longer than its greatest breadth; surface hairs long. Segments of body well differentiated; each dorsal segment with 6 hairs in a transverse series beyond middle, the outer one on each side very short, the middle one very long, and the inner shorter than the latter but much longer than the outer; lateral margin of each segment with a pair of hairs, the anterior one very short, the posterior one very long; hairs on apical segment long and equal, the segment rounded posteriorly; ventral segments, excepting the apical one, each with 6 subequal hairs in a transverse series. Imago.—Antennae short, third joint disc-like; arista very short- haired ; eyes large, with vertical color-bands, those of the female rather widely separated, those of the male narrowly so. Thorax with de- cumbent silvery pile; scutellum with a posterior marginal ridge. Ab- domen short, rounded, subglobose. Third vein of wing furcate. HABITS OF LARVAE The larvae are found under bark of trees that has become slightly loosened. They feed upon the sap and upon insect larvae and are very sluggish. HABITS OF IMAGINES The flies frequent leaves of trees in the sunshine, and are very de- liberate in their movements, walking slowly, but they take flight sud- denly, though they fly rather heavily as compared with most members of the subfamily. I know of no parasites of any stage in this genus. Key To IMAGINES 1. Arista with very dense whitish pubescence which gives it the ap- pearance of being thickened; third antennal joint disc-like; scutellum not regularly convex on disc, the center with a slight hump; pile on sides of mesonotum arranged in small punctiform TOM DEL oh odo SEB e nod otc AE ord Coan CECI eee punctifer. — Arista with very little pubescence, appearing filiform; third an- tenal joint much higher than long; scutellum regularly convex on disc; pile on sides of mesonotum arranged in irregular short GANS 6 go8 abiero.nd ceed is Coens Eaekerecntie (ole ne ek te ee eae henshawi. 338 EUPACHYGASTER PUNCTIFER Malloch ; Eupachygaster, punctifer Malloch, Ann, Ent. Soc. Amer., Vol. 8, 1915, p. 316. The eyes are marked and colored as in henshawi except that the anterior margin does not have a distinct stripe and that the other stripes are broader, the violaceous blue one continuing almost to the lower margin. The thorax has a central narrow stripe of silvery pile, the lateral portions of the disc being adorned with punctiform groups of similar pile. The basal half of the abdomen is devoid of puncti- form groups of silvery pile. This species was described from a single female specimen taken - by Dr. Nason at Algonquin, Ill., which bears no date of capture. The other specimen referred to in the notes on this species given under the original description belongs to the next species. I took a female example of punctifer in a wood. near an old orchard at White Heath, Ill., June 24, 1916. EUPACHYGASTER HENSHAWI, N. sp. Larva.—Length, 7 mm. Dark brown, shining, head and lateral margins of segments paler. Head as in Figures 4 and 5, Plate XLIX; antennae small, pointed, located on disc well back from lateral margin; dorsal and ventral armature as in figures. Armature of dorsum of thorax and abdomen as in Figure 9 (puparium) ; thoracic segments on their ventral sur- face with 6 hairs in a transverse series, the outer two on each side of each segment contiguous basally; ventral abdominal segments each with a transverse series of 6 long hairs, the outer one on each side of each series longer than the others, each series occupying about half the width of segment; anal opening elongate, with 2 short hairs on each side close to margins of the opening; disc of apical segment with 2 long hairs, one on each side before middle and about midway from anal opening to lateral margin. All hairs microscopically pubescent. Imago; Female.—Black, very distinctly shining. Frons and face shining black, the center of former slightly obscured by the presence of a number of piliferous punctures; a conspicuous stripe of silvery pile, beginning above antennae on lateral margins of frons, extends down over sides of face to lower margin-of eyes; antennae yellow, the inner sides of first 2 rings of third joint glossy reddish brown; arista whitish; eyes with 4 vertical dark stripes, one on center, deep violaceous blue, extends from upper margin to a point one fifth dis- tant from lower margin, the others (purple) being a slender one along 339 anterior margin, a broad one extending from lower margin almost to upper margin between the former and the blue central stripe, and a rather broad one along posterior margin. ‘Thorax glossy black, the disc very densely punctate, so that it appears less glossy than the sides; center of disc with a narrow line of silvery pile which extends pos- teriorly to the diagonal median sutures, the latter with similar silvery pile; sides of mesonotum with silvery pile which is arranged in short irregular stripe-like groups anteriorly, and rather evenly on the entire surface posteriorly ; scutellum without silvery pile. Abdomen slightly shining, the surface with piliferous punctures, the hairs slender and rather sparsely and regularly arranged. Legs yellowish white, coxae, trochanters, and femora except their extreme apices, shining black. Wings hyaline, veins pale yellow. Halteres brown, knobs white. Frons about one fourth the width of head, distance from upper extremity of lateral silvery stripe to anterior ocellus greater than its width at former point; antennae larger than in punctifer, third joint higher than long; arista slender, hair-like; antennae inserted below middle of eye, in profile. Scutellum more elongate and less abruptly humped than in punctifer. Abdomen differing from that of punctifer in the absence of the punctiform groups of silvery pile. Male.—Three male specimens which I have reared differ from the female in having the eyes much closer above, the distance between them not exceeding one tenth the width of head, the antennae smaller and with the third joint conspicuously browned apically, and the eye with only 2 vertical purple stripes—one along anterior margin and the other just proximad of middle, the latter not extending to lower margin. In other respects the sexes agree very closely. Length, 4 mm. Type from Savoy, Ill, May 4, 1916, larva under loose bark of apple-tree; imago emerged June 17, 1916. Paratypes from Urbana, Iil., October 21, 1916, larvae under bark of felled elm-tree; imagines emerged December 29, 1916 and January 5, 1917. I have pleasure in dedicating this species to Mr. Samuel Hen- shaw, of the Cambridge (Mass.) Museum of Zoology, who kindly submitted the material in that collection for examination when I wrote the paper containing the description of punctifer. There is a specimen of henshazwi in the Cambridge collection about ihe sex and identity of which I had some doubt when I examined it. It agrees in every respect with the female now before me. It seems worth mentioning that while the eyes of both of the above species have vertical color-stripes, Pachygaster pulcher has 4 340 slender horizontal stripes on center, and Neopachygaster maculicornis has the upper half of eye, except the narrow posterior margin, purple, the remainder being yellowish. ZABRACHIA Coquillett There is only one species of this genus recorded for North America. GENERIC CHARACTERS Larva and Puparium.—Similar in general appearance to that of Eupachygaster henshawi, differing as stated in key to genera. ZABRACHIA POLITA Coquillett Zabrachia potita, Coquillett, Bull. 47, N. Y. State Mus., p. 585. (1901) Larva and Puparium.—Length, 3.5—4.5 mm. Dark reddish brown. Head as in Eupachygaster, the bristles longer than in Neopachy- gaster. Arrangement of bristles on body as in the other genera of the Pachygasterinae, but their relative lengths different. The large lateral abdominal bristle in Zabrachia is not nearly as long as width of abdomen, while in Eupachygaster it is quite as long as the segment which bears it. The other distinctions are indicated in the key to genera. I have ascertained the above facts from an examination of a speci- men spent me by C. W. Johnson, from Massachusetts. Subfamily XYLOMYIINAE* Williston places the genus Xylomyia in his subfamily Arthro- _ceratinae, along with the genera Glutops and Arthrocera, His note on page 387 of his Manual would appear to indicate that he considered Misgonvyia as belonging to the same subfamily. None of the three genera which he includes with Xylomyia are known to me. If they belong to the same subfamily as Xylomyia the name of the subfamily should be Xylomyiinae, unless one accepts Solva Walker as a prior name for the genus Xylomyia. XyLomyia Rondani I have seen the larva of but one species of this genus. It agrees generally with that of Xvlomyia maculata Meigen as figured by *T have retained the name Xylomyia here though the evidence that Solva Walker has priority is very strong. 341 Verrall*, but differs noticeably in having two hairs instead of six on the dorsum of the thoracic and abdominal segments. It is quite prob- able that pallipes is not congeneric with the other species, good charac- ters existing in larvae and pupae which may be used for their separa- tion. When emerging the imago withdraws the pupal skin either largely or entirely from the puparium. No other genus of Stratiomyiidae known to me does this. The pupa closely resembles that of Xylophag- idae. GENERIC CHARACTERS Larva.—Head large, posteriorly retracted within prothorax; an- tennae sessile; maxillae with slender transverse ridges. ‘Thorax and abdomen with a few strong hairs on each segment. Prothoracic spiracles large. Anal spiracles separated, situated in a terminal cham- ber the margins of which protrude lip-like. I give a synopsis of the imagines of the North American species of Xylomyia as the only available ready means of identifying them. The key presented may prove useful to students and save valuable time otherwise required to look up isolated descriptions. Key To SPECIES weeeelind. remora, spimose: beneath. o... . ccs cc esse ee closes 0s pallipes. eB TIC ES LEINOVATIMATIN Cle che, ote) a0 6) ous; 210 a eVene «)<0his)sn0 eo. a.eshn: #1 8ie e aearee weve 2 PME OSA CA CK stag ciateteies cle sayacsiecre kv s © 21dGs aes ue) 00) visio ei a ieheye 818s parens. SINR CHINATO MD ATHY! LO Wile nia.) sexe n 151s & oiejors oye cveraieve vies. 6.0 levars, cise 3 3. Thorax with 2 well-defined vellow vittae on dise........ americana. — Thorax without well-defined vittae..............0ccccecececers 4 4. Hind femora entirely black.......... .........0000- aterrima, 2. — Hind femora wholly or largely yellow................00eee cues 5 5. Pleurae entirely black; hind femora reddish yellow............. 56 bP DA-0 OS OO ELA UPN CIS DORE ODIO LOE ARC on neem pallidifemur, 2. EM CHEAG GOALU Ys VELLOW ais. sto stares. s deletes sicle sfé Mare cla sobie ae ee eevee 6 6. Halteres yellow with a brown spot at base of knobs; antennae black iS 6b DOD ES Bron COO Oe SO ao Cee aterrima, ¢. — Halteres yellow; antennae reddish on inner side................ 7 7. Hind coxae blackened in front; hind femora reddish yellow; eyes separated by less than one sixth the head-width; furcation of fourth and fifth branches of radius distinctly distad of a line drawn from apex of third branch of that vein to point of furea- tion of first and second branches of media...... pallidifemur, 3. *British Flies, Vol. 5, p. 36. (1909) 342 — Hind coxae yellow; hind femora darkened on apical third; - eyes separated by more than one fifth the head-width; fureation of fourth and fifth branches of radius distinetly proximad of, or in line with, a line drawn from apex of that vein to point of furea- tion of first and second branches of media...... tenthredinoides. XYLOMYIA PALLIPES Loew Subula pallipes Loew, Berl. Ent. Zeitschr., 1863, p. 6. Larva.—Length, 7-9 mm. Dark brown, head and thoracic seg- nients yellowish, the latter darkened on sides and posteriorly. Protruded portion of head slightly longer than prothorax, the dor- sal surface with several strong hairs (Pl. XLVIII, Fig. 15), labrum conically produced, the apex very sharp (PI. XLVIII, Fig. 4) ; man- dibles recurved, slightly dentate; maxillae prominent, their ventral surfaces with numerous narrow transverse ridges, palpi inconspicuous (Pl. XLIX, Fig. 7); labial plate as in Figure 10, Plate XLIX; an- tennae sessile; eyes distinct but not protruded; ventral surface of head with a long hair-on each side in transverse line with the eyes. Sur- faces of thoracic and abdominal segments finely shagreened excepting a jarge irregular area on dorsum of prothorax, a narrow transverse area on ventral surface of same segment, a pair of narrow transverse plates on dorsum of metathorax, ‘and the tubercles on_ the various segments. Prothoracic spiracle with 3 openings (Pl. XLVIII, Fig. g). Abdominal segments 2-7 each with a transverse series of small round warts near anterior margin on dorsum; eighth segment with 7 rather large warts in an irregular (2, 3, 2) transverse series proximad of median line, posterior lateral angle with 2 small warts; all ventral segments with a closely placed series of small warts on their anterior margins; anal opening slightly T-shaped, the margins toothed; spi- racles distinctly separated, situated within an apical chamber whose margins protrude lip-like from apex of eleventh segment and appear like an additional segment; thoracic and abdominal: segments, except the apical one, each with 6 hairs, one on each lateral margin and one on each side on venter and dorsum; apical segment as in Figure 14, Plate XLVIII. This description was drawn from larvae obtained by me October 21, 1916, under the bark of trees which had been felled in the spring of the same year. The bark was beginning to loosen, and larvae of Euxesta, Lonchaea, and Heteromeringia were abundant under it. The Xylomyia larvae were found to be predaceous, feeding indiscriminate- ly upon the other larvae. They have a peculiar habit of raising up the thoracic segments when disturbed, but are very sluggish. 343 This species is undoubtedly the commonest of the genus. It was originally described from Illinois and Wisconsin, and has since been recorded from Montana, southern California, Colorado, New Jersey, and “the Atlantic States”. It occurs commonly on tree-trunks in June, July, and August throughout Illinois. Townsend has described the puparium and pupa, and given a brief account of the habits of the species*. XYLOMYIA PARENS Williston Subula parens Williston, Can. Ent., Vol. 17, 1885, p. 122. Described from: Washington State and not subsequently recorded. XYLOMYIA AMERICANA Wiedemann Xylophagus americanus Wiedemann, Dipt. Exot., Vol. 1, p. 51. (1821) This species was originally described from “North America.” It has since been recorded from Mexico, Illinois, and Pennsylvania. I have before me an example from Urbana, IIl., taken June 17, 1916; on a window, and one bearing the label N. Ill., which, I am informed, stands for Algonquin or vicinity. XYLOMYIA ATERRIMA Johnson Xylomyia aterrima Johnson, Ent. News, Vol. 14, 1903, p. 24. This species was originally described from examples from north- ern Illinois and Fredonia, N. H. It is unrepresented in our Laboratory collection. XYLOMYIA PALIIDIFEMUR Nn. sp. Male.—Head brownish black ; 2 spots above bases of antennae and the face whitish pilose; antennae blackish brown, reddish on inner side of basal half; proboscis and palpi yellow. Thorax reddish brown, blackened behind humeri, above bases of wings, in front of scutellum, on a vertical area on anterior half of mesopleura and sternopleura, on the greater portion of the hypopleura, and at the center of postnotum; yellow marks cover the whole of humeri, both sides of the transverse suture narrowly, all of the pleurae except the black portions, and the center of scutellum. Abdomen reddish, the dorsum more or less in- fuscated. Legs pale yellow, hind pair more reddish yellow; anterior *Ent. News, Vol. 4, 1893, p. 163. 344 surface of hind coxae and apical 4 joints of hind tarsi fuscous. Wings clear, veins pale brown. Halteres reddish yellow. ; Eyes separated by about one seventh the head-width; antenna about 1% times as long as height of head, the flagellum slender, apical joint as long as preceding 2 together. Thorax and abdomen with short hairs. Wing venation similar to that of americana, as in- dicated in key. Female.—Differs from the male in having the pleurae entirely black, and the apex of abdomen deep black. The wing venation differs slightly from that of the male, the furcation of radius being but little distad of a line drawn from apex of third branch of radius to point of furcation of first and second branches of media. Length: male, 11 mm.; female, 13 mm. Type locality, Urbana, Ill.; 1 male, June 17, 1890; 2 females, June 1 and 2, 1890,—(C. A. Hart). XYLOMYIA TENTHREDINOIDES Van der Wulp Subula tenthredinoides Van der Wulp,. Tijdschr. v. Ent., Vol. 10, 1867, p. 132. This species was originally described from specimens obtained from Wisconsin. It has since been recorded from Illinois and Penn- sylvania. There are specimens in our collection here from Algonquin, Urbana, St. Joseph, Augerville, and Grand Tower,—lIllinois, all taken in June of various years. SrratTioMymp LARVAE OF UNCERTAIN GENERIC LOCATION GENUS INCERTUS I Larva (Pl. XLIX, Fig. 11).—Length, 7 mm. Pale grayish brown. Head rather long, tapered anteriorly; maxillae armed with nu- merous curved hairs apically; antennae long and slender, apical joint short and stout. Body broad, the surface covered with fine hairs (not shown in figure except along lateral margin) ; each segment with very weak bristles arranged in tranverse series much as in Pachygasterinae. Lateral margins of each abdominal segment except the apical one divided into two lobes, the anterior one slender and acute, the pos- terior one much broader and obtuse; lateral abdominal spiracles rudi- mentary; a number of short bristles surrounding bases of the larger 345 ones composing the transverse series on abdominal segments; apical segment with a conspicuous fringe of long soft hairs; respiratory chamber preapical, rather wide centrally. Described from a specimen obtained in woods at Urbana, IIL, April 30, 1887 (C. M. Weed). This specimen differs so strikingly from any previously described stratiomyiid that I do not feel justified in suggesting its location in the family. GENUS INCERTUS 2 Larva.—Length, 12 mm. Yellowish brown. Head very similar to that of Hermetia, the hairs on anterior por- ion and the antennae short. Body of a more uniform width than in Hermetia, not broadened apically. Thoracic segments with 2 long and 2 or 4 short bristles in a nearly straight transverse row on dorsum, and a group of 2 to 4 bristles on a common base on each side of venter. Abdominal segments except apical one each with 4 rather weak bristles close to posterior margin and 2 very long and strong ones near anteri- or margin; as shown in Figure 8, Plate XLIX; ventrally, the series of 6 bristles nearly straight on each segment and the median two weaker than the others; lateral bristles and dorsal armature of apical segment as in above figure; venter of apical segment with 4 bristles on a dis- tinct ridge proximad of anterior extremity of anal opening, the latter fringed with short upright scales; a series of 4 long bristles distad of posterior extremity of anal opening. Described from a specimen obtained by C. A. Hart in the nest of a cactus rat at Brownsville, Texas, December 1, 1910. GENUS INCERTUS 3 Larva.—Length, 4.5 mm. Yellowish testaceous. Head long, tapering anteriorly; antennae short; maxillae fringed anteriorly and rather conspicuous; most of the surface bristles taper- ing, the one above posterior margin of eye slightly clavate. Body parallel-sided, the surface shagreened and covered with minute scales, each segmental incision marked by a double series of small black dots, and several similar dots on each segment laterally. First thoracic seg- ment with the usual 2 transverse series of bristles on clorsum, the others with a single series of 6 each which are, like those of the abdomen, distinctly clavate; ventral surface of each segment with 6 slightly clavate bristles in almost straight transverse series. Abdomi- nal segments with a single clavate bristle on each lateral margin, 6 346 such bristles on dorsum, and 6 on venter, the latter series not straight and the median two much more widely separated than the others, the” outer one on each side considerably proximad of the others and less noticeably clavate; apical segment with dorsal armature as in Figure i, Plate XLIX; the anal opening unfringed; respiratory chamber small, the opening oval. The foregoing description was made from a specimen submitted along with a larva of Microchrysa polita, and under the same name, by J. A. Hyslop, from Hagerstown, Md. The label indicates that the Jarvae were feeding upon an arctiid pupa. PrIncipAL PAPERS ON NortH AMERICAN STRATIOMYIIDAE Hart, C. A. 95. On the entomology of the Illinois River and adjacent waters. Bull. Ill. State Lab. Nat. Hist., Art. VI, 4: 247-266. Johnson, C. W. 95. Review of the Stratiomyiae and Odontomyiae of North Ameri- ca. Trans. Am. Ent. Soc., 22: 227-278. Malloch, J. R. 15. A revision of the North American Pachygasterinae with un- spined scutellum. Ann. Ent. Soc. Amer., 8: 305-320. Melander, A. L. 703. A review of the North American species of Nemotelus. Psyche, 10: 171-183. Family XYLOPHAGIDAE There can be no doubt that the species herein included should con- stitute a distinct family. The larvae differ from those of Strat- iomyiidae and Leptidae in many respects, and the pupae also are suf- ficiently distinct to entitle them to rank in a distinct family. Without a knowledge of the immature stages of Rhacicerus and Arthropeas 1 do not think it advisable to give a definite opinion on their family status. Brauer in 1882* placed them in Xylophagidae on characters possessed by the imagines. By the use of the same characters he placed Xylomyia (Subula) also in this family, but sub- sequently, in the same publication (1883), he transferred it to Stratiomyiidae because of the characters of the early stages. It will probably be best to retain the two genera in question in Xylophagidae pending further knowledge as to their early stages. Brues and *Denkschr, k, Akad. Wissensch. Wien, math.-naturw. Cl., Vol. 44, p. &6. 347 Melander have placed Arthropeas in Stratiomyiidae and Rhacicerus in Xylophagidae in their recent book*, using the adult characters as their criteria. FAMILY CHARACTERS Larva.—Head not retractile, the exposed portion in the form of a chitinized cone, from a small apical opening in which the man- dibulate portions are extruded; several strong hairs on dorsum. Dor- sum of some of the thoracic segments chitinized entirely or in part, usually in the form of 3 plates; prothoracic spiracle large. Abdominal segments with locomotor spines in transverse series; apical segment obliquely truncated, the apex heavily chitinized, and with 2 backward- ly projecting processes on lower margin; spiracles large, rounded, widely separated, situated above middle of the chitinized plate. Thoracic and abdominal segments each with a number of strong hairs. Puba—Head without thorns except sometimes one on base of each antennal sheath, the latter separated from surface of head, elon- gate, directed almost straight laterad, their apical portions rounded in cross-section and distinctly annulated. Thorax with marginal series of punctures along the sutures; wings extending to apex of first ab- dominal segment; apices of hind tarsi extending to or very slightly beyond apices of wings. Abdominal armature increasing in strength from second segment to apical one, almost absent on basal; apical seg- ment ending in a bifid tubercle. Imago.—The species are very closely allied to those of Leptidae, but may be readily separated from the latter by the structure of the antennae, as indicated in the synoptic key to families of Brachycera. LARVAL AND IMAGINAL HABITS The larvae as far as known live under bark or in earth and feed upon larvae of other insects. The imagines are found generally in woods, and as far as I have observed feed upon nectar of flowers and sap or other liquid matter. XyLopHacus Meigen Krys To SPECIES LARVAE 1. First and second thoracic segments chitinized dorsally...... lugens. — First, second, and a large portion of third thoracic segments chitin- PACH RCLOLS AIL Vee ME Seer ee acl earene A oracles orer yar sie eancv ed abdominalis. *Key to the Families of North American Insects, p. 64. (1915) _ wl w i al x 348 PUPAE Antennal sheath with a thorn at base...................%- lugens. Antennal sheath without a thorn at base............. abdominalis. IMAGINES Legs entirely black, at most the apices of the coxae yellow; basal an- tennal joint much elongated (Mass.).......... longicornis Loew. Legs with a considerable proportion or all of femora and tibiae red- dish, or yellowisht:aae2 tc ows eh ae eee ee ee ee ee 2 Abdomen largely” reddish’ 2. .))..cos0es.- 5 bees ples ona a 3 Abdomen black or blackish brown.............. Soo. oo eee 4 Abdomen ferruginous, sutures and lateral margins of segments black; legs tawny, tibiae and tarsi brownish and darker than the femora(Martin’s Falls and Montreal, Canada) . . fasciatus Walker. Abdomen black, broadly reddish on dise of segments 2 to 5; legs red- dish, apical 2 joints of all tarsi blackened (Texas, N. J.)........ w tiga ict ae ev.ale To] Shah oe ADI teeee a ewacESt catty ee eh ee teeaeere eve abdominalis Loew. Hind legs almost entirely black, only the extreme bases of femora and tibiae and the larger basal portion of metatarsi whitish yel- oie (QUIS INS VenINE dis leh aith dels) oosabwoacdne lugens Loew, 2. Hind legs with a greater proportion of their surfaces yellowish or whitish s:'. dee Usenet ae de Cee ee eee 5 Legs reddish or tawny, only apices of tarsi blackened........... 6 Legs with some portion of femora or tibiae blackened or browned. .7 Antennae not longer than head, entirely black; proboscis (‘‘mouth’’, Walker) yellow (N. Y.).......... reflectens Walker. Antennae longer than head, tip of first jomt and second reddish brown; proboscis black (Wash. State)....... decorus Williston. Legs reddish, apical third of hind tibiae and apices of tarsi black- ened (Mass.; Montreal, Can.; White Mts., N. H.; N. J.; Axton, ING Yd i tteuyd omens eee (persequus Walker) rufipes Loew. Legs yellowish testaceous or pale yellow, femora blackened or dis- tinctly Jbrowned at ‘aMlCes a-p.cversie ise ioistoieke erence rence eee 8 Legs yellowish testaceous, all femora broadly sulfurous apically, tips of fore and mid tibiae, hind tibiae except bases, and all tarsi except bases of metatarsi blackened............ lugens Loew, @. Legs pale yellow, apices of all femora, tips of hind tibiae and of all tarsi light brown (Wash., Oregon)........... gracilis Williston. As this key is largely compiled from descriptions it will be neces- sary to use it with considerable caution. I am not entirely convinced of the specific distinction of several of the species, but without examin- ing the types it is not possible to find characters for the separation other than those given here. Say’s species triangularis is not, I am convinced, a Xylophagus. 349 XYLOPHAGUS LUGENS Loew Xylophagus lugens Loew, Berl. Ent. Zeitschr., 1863, p. 6. Larva (PI. L, Fig. 5).—Length, 15-20 mm. White, slightly shin- ing, chitinized portions castaneous, glossy. Head long and pointed, with a few surface hairs arranged as in Figure 12; anterior opening very small, mandibles normally slightly exserted; the pair of chitin- ized rods which protrude into the first thoracic segment usually visible through the semitransparent membrane at back of head. First and second thoracic segments heavily chitinized on dorsum and with nar- row pale unchitinized longitudinal lines as shown in Figure 5; spiracle large, situated beyond middle of first segment; armature as shown in Figure 5; last thoracic segment not chitinized; ventral surface of first segment with a brown chitinized patch on each side which is dilated anteriorly and tapers to a point posteriorly; occasionally the median space between these patches anteriorly almost covered with small brown spots; second and third segments without chitinized areas; each of the three segments with a hair on each side near lateral margin slightly beyond middle. Dorsum of abdomen with a transverse band of locomotor spines on anterior margins of segments 1-6 which does not extend to lateral margin; each suture, between both thoracic and abdominal segments, marked by a line of small punctiform brown chitinized areas; laterad, except between segments 7 and 8, this line is duplicated, the two lines enclosing a vertical elongate-oval area which ceases at margin of ventral surface; seventh segment with 4-5 poorly developed spines on each side anteriorly, some distance from median line; eighth segment usually with a few round brown spots on anterior portion about midway from median line to lateral margin, and with a larger chitinized spot on each side of disc near posterior margin ; apical segment very heavily chitinized, ending in 2 divergent, slightly upwardly curved processes; spiracles large, round, slightly elevated; dorsum of abdomen, except that of apical segment, without hairs; lateral area of segments 1-7 each with 4 strong hairs arranged in a vertical series on middle of segments, the upper pair more widely separated from the second than the other pairs are from each other; armature of apical segment as in Figure 5; ventral surface different from dorsal in having the locomotor spines present on segments 1-7 and in having a large brown mark surrounding the anal opening. Pupa (Pl. L, Fig. 1).—Length 10-16 mm. Brownish testaceous, slightly shining, turning almost entirely black just before emergence of adult. 350 Antennal sheaths distinctly annulated, the anterior basal surface of each with a stout thorn (PI. L, Fig. 6); entire aspect of head and ~ mouth parts as in figure just mentioned; dorsal surface of head- capsule with 3 small punctiform depressions on ocellar region and on -ach side a single hair; suture between cephalic and thoracic segments deep, the posterior margin of the former with short longitudinal im- pressed lines. Thoracic spiracle much elevated, in the form of a short stout tubercle, the apical opening small, somewhat 8-shaped; protho- rax with a transverse discal, linear series of small closely placed round depressions ; mesothorax with 2 faintly indicated sutures and 2 rather large poorly defined depressions, one behind the other, above wing- base; wings without discal protuberances, their apices rather widely separated, extending distinctly beyond apices of fore tarsi; apices of mid and hind tarsi curved towards median line, the latter extending little beyond apices of wing. Abdominal spiracles similar in form to those of thorax but not so much elevated; first dorsal abdominal seg- ment with 4 weak, widely separated hairs on disc near posterior mar- gin, the median pair much closer to each other than they are to the lateral hairs; lateral areas with 4-6 hairs; segments 2—7 each with a transverse post-median series of closely placed hairs which become progressively slightly stronger from 1 to 7; eighth segment with 4-5 spines on each side of disc in a transverse series; postspiracular area of first segment with 7-8 strong bristles; ventral segments similar in armature to dorsal; apical segment of female as in Figure 2, Plate L. Larvae of this species were common under bark of a felled elm at White Heath, Ill, March 12, 1916. Several specimens pupated from 3 to 5 days after being brought to the laboratory, and the first imago emerged on March 22, others appearing on the 25th and 26th. When collecting the larvae I also captured several larvae of Saperda tridentata, and others of Meracantha contracta (Coleoptera), which I brought in to ascertain whether the xylophagid would eat either of them. One of the Meracantha larvae was eaten, the entire contents being extracted through a hole made in the skin; but the Saperda was not attacked. It is very probable that the food of the xylophagid does not consist wholly of the larvae of Mcracantha as this species was rarely met with in company with the larvae of the fly, and probably Saperda is also eaten. The logs in which I found the larvae were second-year lumber on which the bark was not very loose. When the borings of other in- sects have thoroughly loosened the bark, conditions are apparently not suitable for the larvae, as none were found in such logs. 351 The larva and pupa of this species have previously been described by Johnson* and by Felt}, the latter donating an imago and pupal exuvium of lugens to the collection of the Laboratory. Originally described from Illinois, lugens has subsequently been recorded from Riverton, N. J.; and from Pennsylvania, New Hamp- shire, and New York. XYLOPHAGUS ABDOMINALIS Loew Xylophagus abdominalis Loew, Berl. Ent. Zeitschr., 1869, p. 163. Larva.—Length, 16-21 mm. Differs from larva of lugens as follows: the longitudinal pale streak on second thoracic segment sim- ple, not Y-shaped; third thoracic segment with conspicuous, brown, chitinized dorsal patches (Pl. L, Figs. ro, 11) ; thoracic and abdominal hairs much weaker and paler. Pupa.—Length, 14 mm. Differs from pupa of lugens as follows: antennal sheath without basal thorn (Pl. L, Fig. 7); ventral aspect of head and mouth-parts as in same figure; dorsum of head with about 12 long hairs on each side of disc; thoracic spiracles less elevated; apical segment of abdomen with the bifid process shorter and stouter. The examples used for the above descriptions were supplied by C. W. Johnson and were found under the bark of a decaying pine-tree at Riverton, N. J. The species was originally described from Texas, and has not been recorded from any locality except Riverton as far as I am aware. Family COENOMYIIDAE Only two genera and three species are considered as belonging to this family in North America, but if the catalogues are to be credited one of these, Coenomyia pallida Say, has been described by various authors under sixteen or more different specific names. In Aldrich’s “Catalogue of North American Diptera’ the name accepted for our species is ferruginea Scopoli. I have some doubt about the identity of our species with that of Europe, as Beling’s description of the larva of ferruginea does not fit that before me, and I use Say’s name for the species in this paper. The differences are noted on a subsequent page. *Ent. News, Vol. 14, 1903, p. 23. {Bull. 155, N. Y. State Mus., p. 121. (1912) 352 I do not know the larvae of Arthropeas; which may not conform to the characters here given for the family. FAMILY CHARACTERS Larva.—In general appearance similar to Xylophagidae. Head rather large, the exposed portion in the form of a strongly chitinized cone, from the small apical portion of which are protruded the man- dibulate parts. Thoracic segments each with a pair of round oval chitinized plates under the skin. Apical abdominal segment obliquely truncated, the lower posterior margin with a pair of projecting proc- esses; posterior spiracles widely separated, situated above middle of apical plate, anterior pair on sides of first thoracic segment. Pupa.—Head without projecting thorns; antennal sheaths ele- vated, the annulation indistinct. Abdomen with comparatively weak armature, which becomes stronger apically; postspiracular areas each with 2 bristles; apical segment with a fan-shaped armature of 5-6 bristles on each side; apical protuberances small. Imago.—Very large, robust species, of a variable brownish or testaceous color. Distinguishable from the Leptidae, in which family it has been placed by some authors, by the elongated and annulated third antennal joint. The males of both genera may be separated from Xylophagidae by the contiguous eyes; both sexes of Coenomyita, by the spines on scutellum; and both genera, by the characters given in key to imagines of Brachycera. HABITS OF LARVAE The larva of Coenomyia pallida is usually found in the ground, those that I have before me being obtained in fields some distance from any timber. They are, however, sometimes found in decaying wood. They are predaceous upon insect larvae. A specimen found in a field near Chicago fed upon white-grubs. The larvae are very sluggish, moving very slowly through the earth, and are almost incapable of making progress upon a smooth surface. I know of no parasites of the larvae. HABITS OF IMAGINES Coenomyia pallida is usually found near streams and more par- ticularly among undergrowth or trees, and is rather sluggish. The food consists of fluid matter or nectar of flowers. 353 CoENOMYIA PALLIDA Say Coenomyia pallida Say, Keating’s Narrative of an Expedition to the Source of the St. Peter’s River, Appendix to Vol. 2, p. 339. (1824) Larva.—Length, 38-45 mm. White; head and chitinized plate on apical abdominal segment castaneous. Body cylindrical, slightly tapered anteriorly. Head large, conical, permanently protruded, the movable portions enclosed except at apex; retracted portion consisting of an arcuate dorsal plate and 4 slender chitinized rods (Pl. L, Figs. 3 and 4). Thoracic segments not chitin- ized externally, but each with a pair of chitinized internal plates which decrease in size from prothorax to metathorax, the anterior pair transversely oval and occupying the greater portion of the ventral sur- face; ventral hairs of moderate length. Apical abdominal segment with a heavily chitinized plate, the upper margin of which is proximad of the lower, giving the segment the appearance of being obliquely truncated; spiracles round, situated above middle of apical plate; lower margin of plate with 2 short, stout processes (Fig. 9). Pupa.—Length, 30-35 mm. Dark brown, subopaque. Head, viewed from in front, as in Figure 8, Plate L, the antennal sheath elevated, with minute thorns, the annulation indistinct. Wings short, extending to apex of first abdominal segment; apices of hind tarsi scarcely extending beyond apices of wings, and closely fused to the latter; thoracic spiracles sessile. Abdominal spiracles of moderate size, their breadth less than their height; basal dorsal abdominal seg- tent with 2 bristles on each side beyond middle; second and follow- ing segments up to and including seventh with a complete transverse series of short spines and 6 or more long bristles, the armature in- creasing in strength up to seventh segment; eighth segment with a zroup of 2-4 bristles on each side of apex above, a lateral vertical series of 5 longer spines on a raised base, and a pair of stout pro- tuberances, on a single base, on ventral surface at apex (Fig. 12); postspiracular area of each segment with 2 strong bristles; ventral segments with armature similar to that of dorsal but noticeably stronger ; apical segment as in Figure 13. The above descriptions were made from specimens obtained in illinois, the data being as follows: Du Quoin, August 13, 1908, turned up by plow (L. M. Smith) ; larval exuvium and pupa, Chicago, Au- gust, 1913 (D. K. McMillan) ; pupal exuvia, Havana, June 15, 1894 and Grafton, August 26, 1905. The larva obtained by Mr. McMillan fed upon white-grubs in confinement, and as it was taken in a field where these were common 354 it is very probable that they constituted its food there. ‘The specimen taken by Smith was taken in company with larvae of Asilidae and probably fed also upon white-grubs, which are the principal food of the asilids. ‘The pupal exuvia listed were found protruding from rot- ten tree-stumps. In addition to the above we have imagines in our collection here from Algonquin, Chicago, and Fourth Lake—all in Hlinois. The larvae of the European species ferruginea Scopoli, is de- scribed as having the second thoracic segment with 5 chitinized longi- tudinal dorsal bands. I can not find these bands on any larvae avail- able to me, and consider it possible that our species may not be the same as the European one. Family ACANTHOMERIDAE This family is found only in Central and South America, and is considered by some authors as doubtfully separate from Stratiomyi- idae. The larva of one species has been figured by Brauer*, and its gen- eral appearance and the structure of the cephalic, thoracic,-and apical abdominal segments ally it closely with Coenomyiidae. Superfamily Tabanoidea I have placed in this superfamily the families Tabanidae and Leptidae. SUPERFAMILY CHARACTERS Larva.—Head small, wholly or partly retracted, permanently re- tracted portion with an arcuate dorsal plate over the longitudinal rods; mandibles strong, hook-like, curved downward; maxillae well de- veloped, wholly or largely membranous, the palpi well developed; antennae distinct, pedunculate. Body cylindrical, with or without pseudopods; lateral abdominal spiracles absent in Tabanidae, small but no lateral spiracles distinguishable in Leptidae; apical spiracles in a vertical fissure in Tabanidae, exposed and separated in Leptidae. Pupa.-—Head without strong cutting armature; antennae with or without distinct annuli. Thoracic respiratory organs sessile. Wings and legs closely fused to each other and to thorax; fore tarsi over- lying mid pair, the latter overlying hind pair, the pairs successively longer, hind pair not extending beyond apices of wings. Abdomen *Denschr. k. Akad. Wissensch. Wien, math.-naturw. Cl., Vol. 47. (1883) 355 with seven pairs of lateral spiracles; segments armed with transverse series of slender bristles which become progressively stronger from base to apex of abdomen. Imago.—See descriptions under families, and synopsis in key to imagines of Brachycera. Family TABANIDAE FAMILY CHARACTERS Larva.—Head small, retractile, the parts as in Figure 1, Plate LII. Body circular in transverse section, elongate, tapering at both ends, and with encircling locomotor swellings at the segmental sutures in all genera except Goniops. In the latter the cephalic and thoracic segments are very much tapered and considerably longer than the abdominal segments; the abdomen is stout and obtusely rounded apically, the locomotor swellings being on the anterior third of each of the well-differentiated segments. The posterior respiratory organs are close together and situated in a vertical cleft. Pupa.—Head without projecting thorns. Thoracic respiratory organs sessile, connected subcutaneously with a large cavity on each side of median line close to anterior margin of prothorax (PI. LII, Figs. 2, 3). Wings and legs rather short. Abdominal armature con- sisting of 1, or 2 closely contiguous, series of bristles on each dorsal segment except first, and a weaker transverse series on ventral seg- ments; apical segment ending in 6 stout processes which are more or less radiate and pointed (PI. LI, Figs. 4, 5). Imago.—Distinguished from other Brachycera by the peculiar shape of the third antennal joint, the chitinized portions of proboscis, very robust body, and the wing venation. HABITS OF LARVAE Aquatic or semiaquatic, found rarely among decaying leaves or in low and somewhat marshy spots in fields. As far as known, the larvae are predaceous, the food of the species occurring in rivers being most- ly tipulid and other larvae which burrow in the soft banks of the rivers or occur in the river bottom or in drift. Some species are kept in check by the destruction of their eggs by hymenopterous parasites. HABITS OF IMAGINES The adults of this family are familiarly known as _ gadflies, horseflies, clegs, breeze-flies, etc. They rank with the worst of the 356 biting pests that affect cattle. The species of Tabanus attack cattle and other farm animals almost exclusively, but Chrysops is a per- sistent pest to human beings also, especially near rivers, lakes, or large pools. At least one African species of Chrysops is responsible for the conveyance of a disease affecting man, which in some respects re- sembles filiariasis—a disease conveyed by mosquitoes. Some interesting data upon the egg-laying and other habits of this family are contained in the papers listed at the end of the text on the family. Kry TO GENERA LARVAE 1. Body eclub-shaped, the thoracic segments slender, the abdominal seg- MENtS VODUSL sees sects eit ca erate aie sitions seremerers Goniops (p. 356). — Body tapered anteriorly and posteriorly, not club-shaped........ 2 Apical antennal joint much longer than the preceding joint ; dorsum of thoracic segments as strongly striated as those of abdo- MGI: @ sites datietshoals ae Ae oe etree CORO aston Chrysops (p. 357). — Apical antennal joint not longer than the preceding one; dorsum of thoracic segments either smooth or not as strongly striated as those Of abdomen). merce pees ae ee sanyo ieier ere meas Tabanus (p. 358). we PUPAE 1. One spine on each side of median line on dorsum of each abdominal segment much stronger than the others in the series. . . .Goniops. — The spines of each series either of an almost uniform strength, or at least no two spines conspicuously stronger than the others. .2 2. Antennae projecting beyond lateral margin of head; abdominal spines uniform in length; head with 4 bristles on dorsum (PI. 1D) oe ett) Poe eit hore IO ipa aarn Ao uort nSi cre Chrysops. —- Antennae not projecting beyond lateral margin of head; abdom- inal spines long and short in each series; head with 2 bristles on Gorsumis (PIs Wm RM ots) reeerys erie keene ee eerie ie Neen tenes Tabanus. Gontops Aldrich GENERIC CHARACTERS Larva.—Mandibles stout, slightly curved, apically truncated; an- tennae elongate, 3-jointed, basal joint stout, tapering apically, about twice as long as apical 2 combined; apical joint much shorter than preapical; maxillary palpi 2-jointed, the apical joint slender and dis- tinctly shorter than the basal. Thoracic segments very distinctly tapered anteriorly, abdomen stout, roughly oval in outline, the whole 357 body appearing pyriform or slightly club-shaped ; abdominal segments with rather irregularly arranged transverse series of locomotor tubercles; spiracular chamber in the form of a vertical slit. Pupa.—Head without projecting thorns; antennal sheath short, curved downward. Prothorax about one third as long as mesothorax; wings short, extending to apex of first ventral abdominal segment ; apices of hind tarsi slightly surpassing apices of wings. Armature of dorsal abdominal segments consisting of stout thorns in a trans- verse series, 2 of which, near middle of segments 2 to 7, are much stronger than the others; laterad the series are discontinued some distance from margins; apical segment with 3 strong thorns on each side, between which are several weaker protuberances. Imago.—The only species of the genus (chrysocoma Osten Sacken) may be distinguished from other Tabanidae by the following characters: third antennal joint consisting of 8 segments, the basal one only slightly longer than the next ; fourth posterior cell open; eyes of female acutely angled above; hind tibiae with apical spurs. HABITS OF LARVAE The eggs are usually deposited on the under side of leaves of various plants, and when the larvae hatch they drop to the ground, living afterwards among the decaying leaves and other vegetable debris. They are very probably predaceous like other Tabanidae. The egg-masses are parasitized by a proctotrypid species. HABITS OF IMAGO The female while ovipositing has the habit—which is very rare among Diptera—of brooding her eggs. The species is very rare, and so far as I know has never been taken in Illinois. For details of life-history see the papers by McAtee and by Wal- ton listed at the end of the family discussion. Curyéops Meigen I have before me a number of larvae belonging to different species of this genus, but only one has been definitely associated with the pupal and imaginal stages. GENERIC CHARACTERS Larva (Pl. LI, Fig. 1).—Spindle-shaped, very distinctly tapered towards each extremity. Head small, entirely retractile; antennae 358 long and rather slender, the apical joint longer than the basal; labrum pointed, armed beneath with some strong short bristles ; maxillae stout, their palpi as long as the antennae and stouter, the joints well dif- ferentiated; mandibles long and strong, distinctly curved downward and slightly backward. Thorax sometimes with 8 slightly elevated areas that appear somewhat like plates—a broad one on venter, a similar one on dorsum, and 3 narrow ones on each side. Body with close longitudinal striae; pseudopods distinct, arranged in a circular series on anterior margin of each abdominal segment except the apical one; apical segment with the spiracular portion retractile, the spiracles in a vertical cleft. Pupa.—Similar in general appearance to the pupa of Tabanus (PI. LI, Fig. 6), the principal differences between the genera as stated in the key. Tananus Linné -In point of numbers this genus is the largest of the family, and it also contains the largest species, some of them exceeding an inch in length. GENERIC CHARACTERS Larva.—The larvae of Tabanus closely resemble those of Chrys- ops in general structure, being elongate, circular in cross-section taper- ing at both extremities, and armed, at least on the abdominal seg- ments, with more or less well-defined pseudopod-like tubercles—2 on dorsum and 4 on venter—which usually form an almost complete circle on the segments anteriorly. Head as in Figure 1, Plate LII. The structure of the antennae separates the two genera. Pupa (Pl\. LI, Fig. 6).—The antennae are shorter in Tabanus than in Chrysops, the thoracic spiracles are rather different in structure, being more nearly vertical, and the abdominal armature dif- fers as indicated in the preceding key to genera. Imago.—The hind tibiae differ from those of Chrysops in having apical spurs. From other Tabanidae possessing hind tibial spurs the species may be distinguished by the 5-segmented third antennal joint, with its distinct dorsal basal angle, and the absence of a cilia of hairs on the hind tibia. HABITS OF LARVAE See under family. HABITS OF IMAGINES The species of this genus are very serious pests of cattle, and cause considerable loss to cattlemen in well-watered areas where they 359 occur commonly. Some success in destroying the flies has been at- tained by spreading a film of kerosene on the surface of pools where the insects occur. The flies have a peculiar habit of dipping down to the surface of the water, assumably for the purpose of drinking, and when the oil is present large numbers are destroyed. Various skin lotions, or washes, consisting of lard and sulphur or of carbolic acid in varying strength, have been tried as repellents, but usually with very little success. Even hogs that are regularly washed with various crude-oil preparations to destroy lice are attacked freely by such species as atratus. Some of the larger asilids, or robber-flies, prey upon the adults and succeed in killing even the largest of them. Krys To SPECIES LARVAE 1. Body without markings either of color or hairs................. 2 — Body either with a series of distinct brown spots or with brown TDS chars oucatten cede theres ete ekCDIO I a: SIS CROCE Ce en ee 3 2. Body very closely and finely striated, entirely white. Tabanus sp. 1. — Body coarsely striate, abdominal segments each with an indistinct pale annulus on anterior margin...................... costalis. 3. Abdominal segments with very faint anterior annuli...... costalis. — Abdominal segments either with very well-defined anterior annuli or each segment with a brown spot on each side on extremity of MOnsalmLTAUSVELSe TS WEL OE iacin sets ce oe ss eee tyes cece due esl ee eres 4 4. Brown markings consisting of a small spot on the outer extremity of each dorsal abdominal transverse swelling...... Tabanus sp. 2. — Brown markings in the form of well-defined annuli.............5 5. Lateral raised striated areas of prothorax each about as long as the HOTSHIMONEC MEET ie ae oe ees i Aten boonies: lineola. — lateral raised striated areas of prothorax each about half as long as (Skortserll: G7IVE bebo © gp Onc OO CHCA Cliche ARCA a Rem Roe AOR eee eer hei 6 6. Brown stripe between dorsal striated area and upper lateral one dilated posteriorly, causing the former to be parallel-sided on its Mostemoranalin (bl el MRA VG eB in’ cee tsk tothe soe ees atratus. — Brown stripe between dorsal striated area and upper lateral one tapered, or at least not dilated, posteriorly, the sides of the dorsal area divergent throughout their entire length (Pl. LI, Fig. 2)..7 7. Lateral striae of prothorax very fine, opaque, those of metathorax TUICMMCUATHELE SUING Veta ren ome iene. eel as. Tabanus sp. 3. — Lateral striae of prothorax but little finer than those of meso- HMOMAR ere trata cetente ieee cree nyele mete Goan stygius and nigrescens. bo 360 PUPAE Dorsal abdominal segments, except first, armed with an irregular transverse series, or 2 such series, of very stout thorns, their bases very much dilated, slightly caudad of which series there are some- times a few widely separated, much longer spines............. 2 Dorsal abdominal segments, 4 to 6 at least, with 1 or 2 transverse series of short irregular spines the bases of which are not much dilated, and slightly caudad of these is a transverse series of closely placed, very long, slender bristles..................05- 4 Seventh dorsal abdominal segment with 10—12 moderately long thorns in a continuous transverse series, slightly cephalad of which is a transverse series of very short stout thorns longitudinally in line with the spaces between the thorns of the posterior series... . sie a ats chcae e scvelleiepeto aiwisyouoiere hay treesie eval atone iets carolinensis Macquart. Seventh dorsal abdominal segment with the posterior transverse series consisting of 2 long, widely separated spines on middle por- tion, and several, closely placed, on each lateral extremity which are but little caudad of the much shorter thorns of the anterior BOLUGS ca. acy sess cussaienso is ea ar ate shee Que aie erste nal eho etal ai ieee 3 The portion of head-capsule between bases of antennae distinctly elevated, flattened, strongly rugose, the lower extremity of the ele- vation strongly carinate and with a central incision; abdominal armature very strong, having much the appearance dorsally of a single irregular transverse series on-each segment.............. ata eins me See Nes Rastogi ech RIO Re eee lasiophthalmus Macquart. The portion of head-capsule between bases of antennae slightly ele- vated, rounded, faintly rugose, and not carinate or divided below ; abdominal armature moderately strong, distinctly biserial lat- Orally es ic ears eensyenere eked eR eRe Ee epistates Osten Sacken. Small species, 20 mm. or less in length; abdominal spiracles with C-shaped! im ate cnc,snc:ckeve Seietee oe else eee eS OO ee ae 5 Larger species, at least 25 mm. in length; abdominal spiracles with very much elongated vertical rima, the upper and lower extrem- ities suchtlyrcurved morward=er scence eiciee ieeeiet ete ee ae 6 Bristles on eighth ventral abdominal segment fused basally, giving them the appearance of an elevated ridge with a serrate edge.... Wass olan Gisteslecs SIG EMMIOlE shane esos ee REO eee lineola Fabricius. Bristles on eighth ventral abdominal segment not fused basally... . aT, a Ola Orono pia ord Cones AE costalis Wiedemann. The long spines on dorsal abdominal segments with a ring beyond middle and their apices black; short spines on median portion of each anterior transverse dorsal series stout and almost uniform in Jeneth: +5 creme clacis nae eee eer atratus Fabricius. The long spines on dorsal abdominal segments either black-tipped or all pale, without a black preapical ring; short spines in ante- rior dorsal series slender and very uneven.............--.+0+- 7 361 7. A small but distinct tubercle just in front of base of middle leg in addition to and some distance above the one bearing the paired AIT RP Ee oc cia Sacre athletes oats nigrescens Palisot de Beauvais. — No tubercle present as above...............0.eeeeeee stygius Say. In order to keep this paper within reasonable limits I have not drawn up descriptions of the larvae and pupae of this genus, reserv- ing that for a future article in which I hope to cover the family. Most of the species have already been described by C. A. Hart in his paper “On the Entomology of the Illinois River and Adjacent Watersy. My Species 1 is the only larva not included in that paper. It differs from the other larvae before me in being entirely white and without lines or patches of pubescence, as well as in being. more robust, and less tapered at the extremities. In general appearance it very closely resembles an asilid larva, the resemblance being accentu- ated by the small size of the locomotor organs; and it stood as “‘Asilidae” in our collection. The specimen was obtained at Pulaski, Ill., June 1, 1910, in a pit-cage used in rearing white-grubs. This is a surprising occurrence as most of the species are confined to damp ground or to aquatic surroundings. The species designated as Species 2 and Species 3 in the key to larvae are Hart’s species a and b. PRINCIPAL PAPERS DEALING WITH THE B10LOGY or NortH AMERICAN TABANIDAEt Hine, J. S. 703. Tabanidae of Ohio. Special Papers, Ohio State Acad. Sci., No. 5. 706. Habits and life histories of some flies of the family Tabanidae, Tech. Ser., No. 12, Pt. 2, Bur. Ent., U. S. Dept. Agr. 06a. A preliminary report on the horse-flies of Louisiana, with a dis- cussion of remedies and natural enemies. Cire. 6, State Crop Pest Commission of La. 707. Second paper upon the horse-flies of Louisiana. Bull. 93, Agr. Exper. Station La., State Univ. MecAtee, W. L. 711. Facts in the life-history of Goniops chrysocoma. Proc. Ent. Soe. Washington, 13: 21. Walton, W. R. 08. Notes on the egg and larva of Goniops chrysocoma (0. 8. ). Ent. News, 19: 464. *T do not know whether this character will hold good in a series as my material contains only one specimen of nigrescens (in very poor condition) and but 2 of stygius. .tBull. Til. State Lab. Nat. Hist., Vol. 4, Art. VI. (1895) tSee also C. A. Hart’s Art. VI, Vol. 4, Bull. Ill. State Lab. Nat. Hist. (1895) 362 Family LEPTIDAE In the present paper I have limited this family to include only the genera placed in the subfamily Leptinae in Williston’s Manual of North American Diptera. This grouping is not a new one, having been used by Brauer and several subsequent writers, and from a phylogenetic point of view it has much to recommend its general adoption. FAMILY CHARACTERS Larva.—Head with a rather small protruded portion; maxillae not so prominent or so heavily chitinized as in Asilidae, closely re- sembling those of Tabanidae; maxillary palpi well developed; man- dibles vertical, parallel, curved, and very long; retracted portion of head with a large arcuate upper covering which is not very heavily chitinized, and 4 elongate rods. Body in terrestrial forms circular in cross-section, distinctly tapered anteriorly, without pseudopods; lateral spiracles on metathorax and abdomen very small; in aquatic forms body slightly flattened and with paired abdominal pseudopods and dorsal and lateral filaments; anterior spiracles small; posterior pair large, located, in terrestrial forms, under a single flap-like process or at the base of an upper pair of pointed processes; in aquatic forms the spiracles are not distinguishable, and there are two rounded, pro- trusive blood-gills on apical segment below the bases of the long terminal appendages. Pupa.—Head without projecting thorns; antennae short, swollen at base, slender apically, directed downward and slightly outward. Thoracic respiratory organs sessile (terrestrial forms) ; wings extend- ing to second or third abdominal segment ; hind legs extending to apex of wings or slightly beyond that point. Abdomen with a transverse series of bristles on each segment, the series becoming stronger towards apex of abdomen. Tinago.—Robust species with short antennae and stout legs. For characters to distinguish the family from other Brachycera see key to imagines of this division. HABITS OF LARVAE Only one genus known to me is aquatic—Atherix. The terrestrial forms are found in rotten wood or in the ground in woods, generally under thick covering of leaves or under decaying logs or tree-stumps. They are predaceous, feeding upon larvae of other insects, and prob- ably also upon worms. The species which I have reared were very 363 sluggish in the larval stage, but Beling mentions that one species in Europe is very active. The larvae are frequently attacked and killed by internal nematode parasites. HABITS OF IMAGINES Some species are predaceous, feeding upon soft-bodied insects, but the greatest number are found upon flowers. Tree-trunks or fence-posts are favorite resting-places of the species of Leptis, where they invariably assume a position with the head downward. Some species of Chrysopila usually frequent the densest portions of wood- lands, and others are found commonly only on marshy ground. Several species of Symuphoromyia are known to attack man and cattle in this country, inflicting very painful bites. The females of the genus Atherix have a peculiar egg-laying habit. The eggs are deposited upon branches or twigs of willow or other trees overhanging streams. After oviposition the female does not fly away, but dies and remains attached to her egg-mass. A second female adds to the already deposited mass both her eggs and her body, and gradually others do likewise, until the combined mass of eggs and flies assumes considerable proportions, often containing several thousand dead flies. The larvae which hatch, drop from the mass into the stream below, where they pass the immature stages. ‘The Indians in Oregon at one time collected the masses of eggs and flies and used them as food. An interesting account of this aboriginal utilization of nature’s resources is given by Prof. J. M. Aldrich.* Kry To GENERAt LARVAE 1. Apical abdominal segment ending in 2 long stalk-like processes, which are fringed with long soft hairs; paired pseudopods present on abdominal segments; aquatic species................Atheriz. — Apical abdominal segment ending in 2 fleshy lips or in 4 tapering points, the spiracles situated at the base of the upper processes; paired pseudopods absent; terrestrial species................. 2 Apical abdominal segment ending in 2 fleshy lips, an upper and a lower, the inner surfaces of which are brown....Symphoromyia. — Apical abdominal segments ending in 4 pointed processes, the inner NULCACCHLOR WUTeheanen paler cite ey. cca it.)s.\e. allel cxreiidiek and bo *Ent. News, Vol. 23, 1912, pp. 159-163. tI have pupae of Chrysopila only, and can not give a key for the separation of the genera in this stage. For a key to the imagines use should he made of that to Leptinae in Williston’s ‘‘Manual’’. 364 3. A small projection on outer under side of base of upper protuber- ~ ANEOs <).'2 frais sais «+s oct Se Re eee eee Chrysopila. — No small projection on outer under side of base of upper protuber- AICO ls... vet n Siotaye eynte lea rose h cctere oleh tataeye Bune Ta te BR ae alee Leptis. ATHERIX Meigen GENERIC CHARACTERS Larva (Pl. LI, Fig. 10).—Head small, entirely retractile, inter- nally pyriform. Abdomen with lateral appendages and _ well-de- veloped paired pseudopods which are armed with curved apical spines, as shown in Figure 10, Plate LI1; apical segment ending in 2 long protuberances which are fringed with long hairs; 2 rounded blood-gills below base of apical protuberances, Pupa.—Unknown to me. Imago.—The species differ from fHioke of other Leptidae in pos- sessing the following combination of characters: third antennal joint reniform; basal antennal joint not thickened; arista dorsal; third tibiae with 2 spurs; front tibiae without apical spurs; anal cell closed; discal cell present. HABITS OF LARVAE The larvae are aquatic, living in flowing streams. I have not seen any larvae of this genus from Illinois, the material before me being all from streams in Yellowstone National Park (S. A. Forbes) and from mountain streams in Montana (C. C. Adams). HABITS OF IMAGINES See under family. SympPuHoromyia Frauenfeld I have not seen larvae of this genus, and the characters used in the key are from Beling’s published description of a European species. Curysoriia Macquart GENERIC CHARACTERS, Larva (Pl. LI, Fig. 6).—White. ‘Tapered anteriorly, stout posteriorly, the apical segment ending in 4 stout processes, between the lateral pairs of which is a smaller process (Pl. LII, Fig. 11) ; head as in Figure 8. Anterior spiracles small, lateral metathoracic and 365 abdominal pairs minute, posterior pair large, circular, situated on ven- tral surface of the upper pair of apical processes. Body bare except for the usual 6 thoracic hairs. Pupa (Pl. LII, Fig. 7)—Head without spines; antennae stout basally, slender apically, directed downward and slightly outward; thoracic respiratory organs sessile. Wings and legs short, extending to apex of first segment. Abdomen with spinose armature which be- comes stronger apically; apical segment with stout processes which are not thorn-like. : Imago.—Distinguished from other genera by the following characters: third antennal joint conical or subconical, with a slender terminal arista; discal cell of wings present; 5 posterior cells; anal cell closed; hind tibia with 1 spur. HABITS OF LARVAE AND IMAGINES See under family. Keys TO SPECIES LARVAE 1. Large species, 15 mm., or more, in length; neither the upper nor lower anal protuberances with well-defined lateral process (PI. ToH, Tbics ID) ee aoe spo a pepaeood Oecd bpp oGan oom oe ornata. — Smaller species, about 10 mm. in length; either the upper or lower anal protuberances, or both, with well-defined lateral process... .2 2. Only the lower anal protuberances with well-defined lateral process (Gi re 2c reas rs uteteveues sete arsces oie. ¢0u o's) ecveyelersy=.o.e7s.a.% quadrata. — Both upper and lower protuberances with well-defined lateral proc- SSceSR Gailey IO) Iai wets ace seats sole eins cee sce eo sp. ? PUPAE 1. Large species, 16 mm., or more, in length; apical abdominal segment RPA CSM EONS 2 (i en N AM HUGS SS )) oro eco iltte, a, )/ Serene aoa terete ile te 2 eae obeteeatene Spogostylum anale. Head with 6 short, stout thorns on upper anterior margin........ 4 The. pair of thorns on lower portion of central line of face small, their bases subcontiguous; hairs of abdomen, except those of verse armature of dorsal abdominal segments 2-6 consists of 12-20 long, closely placed, flattened hairs................00-c0eeeee 12 Lower one of the pair of lateral cephalic thorns simple apically, but with a small wart-like protuberance at base on lower surface, the small wart bearing 2 distinct hairs; wings without discal protu- DIBLAT COS aye Cgc rt Nercrstaceiatcveparehes « craceleerete erect Sparnopolius fulvus. Lower one of the pair of lateral cephalic thorns with a short sub- apical protuberance, the apex of thorn turned upward, base sim- ple; wings each with a pair of protuberances, one about one fourth from base and the other near middle...... Anastoechus nitidulus. No well-developed pair of thorns on lower median portion of face. . ath fos tv cacti Gg RIC ner RE PEE reese Toxophora virgata. A well-developed pair of thorns on lower median portion of face.14 . Eighth ventral abdominal segment without hairs on disc......... Be Peete ras ee AOS cyalaie tiene sere avehavs.pueahane Hyalanthrax hypomelas. Highth ventral abdominal segment with hairs on dise........... 15 Highth ventral abdominal segment with 2 hairs on each side of disc; distance from the pair of thorns on lower central portion of head to apex of basal portion of sheath of mouth-parts about 4 times as great as distance from the latter to apex of proboscis........ 4 noAS Sh aloes ade GAR Sen Oertan Bind ceeee Hyalanthrazx lateralis. Highth ventral abdominal segment with 10-12 long hairs on disc; distance from the pair of thorns on lower central portion of head to apex of basal portion of sheath of mouth-parts about twice as great as distance from the latter to apex of proboscis.......... SANDS UO FOe DODCELCO TCC OCR CDAIGHA Era Hyalanthraz alternata. SpoGostyLUM sIMSsON Fabricius Anthrax simson Fabricius, Syst. Antl., p. 49. (1805) Spogostylum simson (Fabricius) Wiedemann, Dipt. Exot., Vol. 1, p. 122. (1821) Pupa.—Length, 20 mm. Brownish testaceous, slightly shining; cephalic and abdominal thorns dark brown. 394 Head with 6 short, stout thorns on upper anterior margin, central pair more widely separated than the others, so that the whole appears as if divided into 2 groups of 3 each; the lower 2 thorns in each group apparently on a single base (PI. LVI, Fig. 6); the pair of thorns on lower portion of central line of face almost conical, widely separated at base; 4 short hairs above base of upper cephalic thorns and one on each side of the lower central thorns. Prothoracic spiracles circular, rather large, margined with minute radiating rugae; metathoracic spiracles indicated by a small elevation; the nor- mal thoracic hairs present; wing-cases without discal protuberance. Transverse armature of first dorsal abdominal segment consisting of a large number of closely place flattened hairs, which are at least as long as head and thorax combined; dorsal segments 2-6 with the median portion of the transverse armature consisting of a number of short stout thorns which are turned up at bases and apices, giving them the appearance of furcate thorns with one point directed caudad and the other cephalad; seventh segment with 2 short simple thorns on each side of median line; laterad of the thorns on all segments are a number (12-20) of long flattened hairs which are very closely placed; postspiracular hairs very long, and, like the others, minutely pubescent; ventral segments each with 2-4 long flattened hairs in a transverse series on each side at middle; eighth segment with 4 hairs, one dorso-lateral and one latero-ventral on each side; apical segment terminating in 2 long, stout, slightly divergent, acutely pointed processes (Figs. 5, 7). Described from a specimen submitted by W. L. McAtee which was obtained from a burrow of Xylocopa virginica in a pine-roofed porch at Plummers Island, Md., July 31, 1910. Osten Sacken says of this species, without indicating his authority, “said to be a parasite of Nylocopa virginica in the United States’’*; and Davidson has recorded it as a parasite of Xylocopa opifex at Los Angeles, Calif. Xylocopa virginica occurs in the southern half of Illinois, the most northerly record we have being Charleston; and simson is represented in our collection by examples from Thebes, Grand Tower, and Graf- ton—all in the southern half of the state. *Biol. Cent. Amer., Vol. 1, p. 100. (1886) tEnt. News, Vol. 4, 1893, p. 153. 395 SPoGostyLUM ALBOFASCIATUM Macquart Anthrax albofasciatum Macquart, Dipt. Exot., Vol. 2, Pt. I, p. 67. (1841) Argyramoeba obsoleta Loew, Berl. Ent. Zeitschr., 1869, p. 29. Pupa (Pl. LVI, Fig. 3).—Length, 15-17 mm. Yellowish testa- ceous, slightly shining. ‘Differs from simson in having the pair of thorns on lower cen- tral portion of face larger and more closely placed, the clypeus with a sharp carina, the hairs on basal dorsal segment of abdomen flattened and all others slender, those of first segment a little shorter than head and thorax combined, and also in the shape of the apical segment, which at its tip is divided into two rather stout processes, each of which has a short projection on its inner surface near apex, and at the base on each side of segment 2 short thorns, as shown in Figure 4, Plate LVI. I have seen pupae of this species sent me by Mr. Phil Rau, and a pupa and partly transformed larva submitted by Dr. Edna Mosher. I do not know the locality of the former, but the latter are from New York State. Imagines of the species are commonly found throughout Illinois, and probably wherever its host, Pelopoeus cementarius, is found. I suspect that several more species names will ultimately be added to the foregoing synonymy, as several species depend upon wing- markings—which are extremely variable—for their separation. REFERENCES TO DESCRIPTIONS OF LARVAE AND PUPAE or NortH AMERICAN BOMBYLIIDAE Spogostylum anale Say, Malloch, Bull. Tl. State Lab. Nat. Hist., Vol. 11, Art. 4, p. 328. (1915) Spogostylum anale Say, Shelford, Ann. Ent. Soe. Amer., Vol. 6, No. 2, 1913, p. 218. Chrysanthrax fulvohirta Wiedemann, Malloch, Proce. Biol. Soc. Wash- ington, Vol. 29, p. 67. (1916) Aphoebantus mus Osten Sacken, Riley, Packard, and Thomas, See. Rep. U.S. Ent. Comm., p. 262. (1880) Systoechus oreas Osten Sacken, idem, ibid., p. 266. Exoprosopa fasciata Macquart, Malloch, Bull. Ill. State Lab. Nat. Hist., Vol. 11, Art. 4, p. 329. (1915) Exoprosopa fascipennis Say, Malloch, ibid., p. 330. Argyramoeba oedipus Fabricius, Townsend, Am. Nat., Vol. 27, p. 60. (1893) Sparnopolius fulvus Wiedemann, Malloch, Bull. Ill. State Lab. Nat. Hist., Vol. 11, Art. 4, p. 331. (1915) 396 Anastoechus mitidulus Fabricius, Malloch, Proce. Biol. Soc. Washington, - Vol. 29, p.68. (1916) Toxophora virgata Osten Sacken, Townsend, Psyche, Vol. 6, p. 455. (1893) Hyalanthrax hypomelas Macquart, Malloch, Bull. Ill. State Lab. Nat. Hist., Vol. 11, Art. 4, p. 334. (1915) Hyalanthraz lateralis Say, Malloch, ibid, p. 332. Hyalanthrax alternata Say, Malloch, Proce. Biol. Soe. Washington, Vol. 29, p. 69. (1916) Superfamily Therevoidea The superfamily name of Polytoma was used by Brauer to cover the families Therevidae and Scenopinidae. This grouping is fol- lowed in the present paper, but the name is changed to Therevoidea to conform to the rules governing zoological nomenclature. CHARACTERS OF SUPERFAMILY Larva.—Head with a cone-shaped anterior protruded portion, which consists of a dorsal sclerite overlapping the sides, and a small ventral sclerite which is not fused to the dorsal one; mandibles well developed; antennae and maxillary palpi distinct; dorsal posterior portion of head consisting of but one rod, the lower rods short or ap- parently absent. Thoracic hairs well developed. Abdominal segments 1-6 divided, the entire body appearing to consist of 20 segments ex- clusive of the head; anterior spiracles distinct; lateral abdominal spir- acles absent; posterior spiracles situated on the antepenultimate seg- ment. Pupa.—Head with a pair of antennal thorns, which are directed laterad. Thorax with a long thorn at base of wing, or if this is ab- sent the abdomen has 2 transverse series of spines on each dorsal seg- ment except basal and apical. g Imago.—Eyes of males in Therevidae usually contiguous, in Scenopinidae distinctly separated; frons not sunken between eyes; proboscis never elongated. Body with or without wooly hairs; if the abdomen and thorax are somewhat leathery in appearance there are only 3 posterior cells on wing and the third antennal joint has no terminal arista. Legs without hairs or bristles in Scenopinidae, with or without small bristles in Therevidae. Family THEREVIDAE FAMILY CHARACTERS Larva (Pl. LVI, Fig. 10).—Very long and slender, tapering towards both extremities; head small, the posterior internal chitinized 397 dorsal extension in the form of a single stout rod with spatulate apex ; mandibles strong, deflected in front and pointed at apices; antennae of moderate length (Pl. LVII, Fig. 1). Prothoracic spiracle distinct (Pl. LVI, Fig. 9) ; each thoracic segment with 2 hairs, one on middle of the latero-ventral line on each side. Abdominal segments 1 to 6 divided by means of a distinct circular constriction, so that the body appears to consist of 20 segments; posterior spiracles on antepenulti- mate abdominal segment; ultimate segment with 2 short points at apex and several surface hairs. Pupa (Pl. LVI, Fig. 12).—Distinguishable from other pupae of the Brachycera by the presence of 2 thorns (antennal sheaths) on head and a long curved thorn at base of each wing. The abdomen has a single girdle of thorns on each segment, and the apical segment ends in 2 long, slender thorns which are contiguous except apically (Fig. as): Imago.—See key to families of Brachycera. HABITS OF LARVAE The larvae are found in the ground and also in decaying wood. I have found one species in wheat fields and in woods. They are predaceous, feeding upon various insect larvae, including wireworms, and under conditions of overcrowding or scarcity of other food they are cannibalistic. HABITS OF IMAGINES The flies are very active, especially during sunshine, when they may be found frequenting bare paths and sandy or exposed banks. I have no data upon their food habits except that they frequent flowers occasionally. I have no record of parasitic enemies of any stage. PsILOCEPHALA HAEMORRHOIDALIS Macquart Thereva haemorrhoidalis Macquart, Dipt. Exot., Vol. 2, Pt. I, p. 26. Imago. (1841) Psilocephala haemorrhoidalis Macquart, Malloch, Bull. Tl. State Lab. Nat. Hist., Vol. 11, Art. 4, p. 334. Larva and pupa. (1915) . This species is the only Psilocephala that I have found in Illinois in the larval stage, although a number of other species of the genus are well represented in our collection of imagines. The habits are as previously mentioned for the family; descriptions of all stages are 398 cited in the above synonymy; and figures of the larva and pupa are given in the present paper (PI. LVI, Figs. 9, 10, 12, 13; Pl. LVI, Fig. 1). PsILOCEPHALA MELAMPODIA Loew Psilocephala melampodia Loew, Berl. Ent. Zeitschr., 1869, p. 9. Imago. Psilocephala melampodia Loew, Felt, Bull. N. Y. State Mus., No. 155, p. 121. Larva and pupa. (1912) This species was reared from a larva found under decaying pine bark at Albany, N. Y., April 8, 1911, and the larva and pupa were described by Dr. Felt, as indicated above. The description of the larva is too short to permit of any com- parison with that of haemorrhoidalis; but the pupa, judging from the description, has much shorter thorns at base of wing. Only a com- parison of the larvae and pupae of the two species will furnish charac- ters for their specific separation. Family SCENOPINIDAE FAMILY CHARACTERS Larva.—Closely resembles the larvae of the Therevidae. The smaller size and different habitat of the species readily distinguishes the larvae from those of that family without dissection, and dissec- tion of the head provides characters for the separation of the species known to me. Scenopinus has the dorsal posterior chitinized exten- sion parallel-sided apically, whereas Psilocephala has it spatulate, and while the latter has a pair of lower chitinized processes projecting beyond the posterior margin of the protruded portion of the head and evidently connected with the mandibles, Scenopinus has no such proc- esses. Superficially the larvae are otherwise similar. Pupa.—The pupa of this family is known to me only from de- scriptions. It is possible, however, to indicate that the species of the two families so far described may be separated by the character of the armature of the abdominal segments—Therevidae having only the apical girdle of spines on the abdominal segments while Scenopinus has an additional one on the middle of each segment. _ _Imago.—Distinguishable from Therevidae principally by the wing venation. HABITS OF LARVAE The larvae of Scenopinus fenestralis are predaceous, feeding upon larvae of other insects, and are found in a variety of situations—in fungi, in rotten wood, under carpets in houses, in roots of plants, ete. 399 HABITS OF IMAGINES Imagines of a few common species may be collected from win- dows. They are not predaceous, feeding as far as we have observed upon nectar or moisture. ScENOPINUS FENESTRALIS Linné Musca fenestralis Linné, Fauna Suecica. (1761) Larva.—Length, 18-20 mm. White. Very slender, tapering towards both extremities. Head conical (Pl. LVI, Fig. 2). Thoracic hairs as long as or longer than the seg- ments upon which they are situated; spiracles distinct (Pl. LVI, Fig. 11). Anterior division of abdominal segments 1 to 6 about one half longer than posterior ; posterior spiracle about one third from anterior margin of antepenultimate segment; apical segment divided (Pl. LVI, Fig. 8), the surface hairs long. The foregoing description was made from specimens obtained at Urbana, Ill., November 3, 1892, under a carpet, where they were feeding upon larvae of Tinea tapetzella (C. A. Hart). The species was not reared and no pupae are available, the charac- ters used in the key and elsewhere in this paper being obtained from published descriptions. The species occurs commonly both in Europe and North America. Tribe ORTHOGENYA This tribe of the Brachycera contains one superfamily, Empididoidea, and two families, Empididae and Dolichopodidae, both of which contain a very large number of species. Superfamily HLmpididoidea CHARACTERS OF TRIBE AND SUPERFAMILY Larva.—The larvae of both families as far as known, differ from others in Brachycera in having the labial plates and the longitudinal rods meeting at right angles, so that in profile they appear bent. The maxillary palpi are usually small and the antennae distinct. In all species that I have examined there are 4 slender elongate posterior cephalic rods, the larvae are amphipneustic, and the locomotor organs are more or less developed, consisting of paired pseudopods, of fusi- form ventral areas armed with spines, or of transverse series of short spinules. The posterior spiracles are upon the apical abdominal seg- 400 ment and well separated, being sessile or nearly so in most species, only rarely elevated; this segment frequently has 4 short terminal protuberances. Pupa.—The head very rarely has 2 long, strongly chitinized pro- tuberances, and the antennae are short, directed downward and slight- ly outward, with 2 hairs on slight elevations at bases, and sometimes 2 or 3 short, compressed teeth on basal half. The proboscis in the Empididae that I have seen is much elongated, projecting much far- ther between the wings than in Dolichopodidae. Brauer has indicated that the former family possesses sessile thoracic respiratory organs, while the latter has these organs pedunculate and slender. I have reared one empid that has the type of respiratory organs which he ascribes to the Dolichopodidae, and this invalidates the structure of the respiratory organs as a differentiating character in these families. The proboscis, as above indicated, may prove useful in separating the families, but I suspect that Ocydromyia and several other genera of Empididae that have the proboscis short, can not be separated from Dolichopodidae by that character. Imago.—Most species of Dolichopodidae are distinguishable at a glance from other Orthorrhaphae by their bright metallic blue or green color and their slender elongate legs. The few genera that are dull in color may be readily separated by their different habitus. The Empididae are usually blackish or brownish slender species with elongate legs, those of the female frequently possessing a fringe of scale-like hairs on some or all of their tibiae or femora. The pro- boscis in the great majority of genera in this family is elongate, slen- der, and fitted for piercing. For synoptic characters see’ key to imagines of Brachycera. » Family EMPIDIDAE FAMILY CHARACTERS Larva.—The labial plates and the longitudinal rods of the head meet angularly, so that in profile they appear bent. The labium con- sists of 2 arcuate bands, which are contiguous and form an angle anteriorly; the mandibles appear in the form of a lunate plate, as shown in Figures 4 and 6, Plate LVII. The antennae are well de- veloped, consisting of 2 joints. The posterior spiracles are situated upon the last segment, well separated and occasionally slightly ele- vated; the last segment is rounded or has a slight protuberance be- low at tip. 401 I have the immature stages of only two genera in my material, and to attempt a generalization of the family and a presentation of the characters for their separation from Dolichopodidae, with which I am almost unacquainted, is impossible. Imago.—See family key. HABITS OF LARVAE The European species are much better known than the American, ‘and from data supplied by workers on that continent, and from my personal observations, it is evident that the larvae are for the most part-either predaceous or scavengers, living in the ground or in wood in a more or less advanced stage of decay. Some species are aquatic or semiaquatic. HABITS OF IMAGINES The imagines are in the great majority of cases predaceous, feed- ing upon other insects and occasionally attacking species of the same family or individuals of the same species. There are published records that the male of some genera catches the prey which serves as a meal for the female during copulation. The sexes of Tachydromia and allied genera catch their own prey, usually while running on tree- trunks. Many species have a habit of flying in swarms, remaining in one place and flying with an up and down movement similar to that adopted by certain Chironomidae. ‘Terrestrial species usually fly in this manner on the leeward side of a tree, bush, or other shelter- ing object; but the aquatic forms and those living in damp earth per- form their aerial dance over the surface of a pool in a stream, or over a pond or lake. Despite their predaceous habits nearly all genera occur upon flow- ers, sometimes in large numbers. RHAMPHOMYIA DIMIDIATA Loew Rhamphomyia dimidiata Loew, Berl. Ent. Zeitschr., 1861, p. 325. Larva.—Length, 7-9 mm. White, head black. General shape musciform, tapered anteriorly, blunt posteriorly. Head when seen from above, as in Figure 4, Plate LVII; the antennae well developed, 2-jointed. Thoracic spiracles small. Abdomen with 8 segments; circular in cross-section; segments broader than long, without dis- tinguishable locomotor organs, apical segment rounded; spiracles large, disc-like, separated by a space about equal to width of a spir- 402 acle, spiracular openings irregular; a group of 3-4 hairs on a slight elevation below each spiracle. Pupa (Pl. LVII, Fig. 5).—Length, 6-8 mm. Yellowish testa- ceous, the armature brown. Head without prominent thorns, the bases of antennae produced in the form of carinate ridges; proboscis thick, elongated. Thoracic respiratory organs in the form of short stalks; surface hairs as in figure. Abdominal spiracles elevated; armature as in figure, the bristles rather slender. The foregoing descriptions were made from material obtained by me at White Heath, IIl., April 2, 1916, from a much-decayed tree- stump. I reared a number of specimens of both sexes under labora- tory conditions, the specimens emerging from ten days to three weeks from date of collection of the larvae, the average duration of the pupal stage being 8 days. No parasites were obtained. No imagines of this species were obtained by collecting in the locality where the larvae were taken, and the species is unrepresented in our Laboratory collection except by the reared examples. Originally described from Maryland and Massachusetts, the spe- cies has not, so far as I know, been subsequently recorded. Drarertis Meigen I have seen the larval and pupal exuvia of but one species of this genus, and these are not in very good condition. This species, migra Meigen, is slightly less than 1.5 mm. in length, and as the exuvia were dried out when I found them the details are not as clear-as they would be in fresh material. The drawings, however, give a good idea of the general appearance of the parts available for study. HABITS OF LARVAE The larvae occur under bark and in decaying wood. Their very small size makes their detection difficult. They spin a remarkably tough cocoon, in which they pupate. The cocoon is densely coated with minute particles of the wood in which the larvae live. - HABITS OF IMAGINES ~ The imagines are very common on tree-trunks and fences, run- ning with great rapidity, and are predaceous upon small insects. They resemble the dolichopodid genus Medeterus in both larval and adult habits. 403 DRAPETIS NIGRA Meigen Drapetis nigra Meigen, Syst. Beschr. Eur. Zweifl. Ins., Vol. 6, p. 344. (1828) Larva.—Length, 2-2.5 mm. White. Musciform; head from above as in Figure 6, Plate LVII. Ab- domen with locomotor spinules in a rather broad band on anterior margin of segments; posterior spiracles large, separated by slightly more than the width of a spiracle; a slightly darkened and raised transversely elongated area below spiracles armed with a few hairs. Pupa (Pl. LVII, Fig. 7)—The pupa differs in many respects from that of Rhamphomyia dimidiata. ‘The chief distinctions lie in the much elongated respiratory organs of the thorax, and in the arma- ture of the abdomen, the latter consisting of a dense covering of small spinules on the greater portion of the dorsum of all segments. The specimens from which the foregoing descriptions were made, are the exuvia of a female reared from a rotten stump at Crystal Lake Park, Urbana, June 10, 1916. With this specimen were many larvae of Clusiodes flaviseta Johnson. Drapetis nigra is a European species that has previously been re- corded from South Dakota and Canada. PAPERS ON THE Brotocy or NortH AMERICAN EMPIDIDAE Aldrich, J. M., and Turley, L. A. 799. A Balloon-making fly. Am. Nat., 33: 809-812. Needham, J. G., and Betten, C. 701. Aquatic insects in the Adirondacks. Bull. 47, N. Y. State Mus. (Notes on the life history and descriptions of larva and pupa of Roederiodes juncta Coquillett are given on pp. 581-582.) Family DOLICHOPODIDAE I have not succeeded in obtaining all stages of any species of this family, and little is known of the early stages in America, only one species in this country being fully described—by Johannsen and Crosby. I have before me the larvae of two species, which were de- scribed by Mr. Hart in his paper “On the Entomology of the Illinois River and Adjacent Waters” cited in the list of publications at the close of this section. These larvae were referred to Brachycera with- out being assigned to any family. The European species are much better known, though few of the descriptions are clear upon many of the essential points. In view of these facts it would be folly to at- 404 tempt a characterization of the larval and pupal stages of the family, but in pointing out the meagerness of our knowledge I hope I may help to remedy it by directing the attention of some student to this line of investigation, which will repay him more satisfactorily for the time and energy expended than will the writing of new descriptions of imagines the life history of which is entirely unknown. HABITS OF LARVAE The larvae have been recorded as predaceous upon other insect larvae. They are found in a variety of situations, but a great ma- jority are aquatic. Dolichopus, Hydrophorus, and Campsicnemus are among the aquatic forms, and Medeterus and Thrypticus are found in plants, the latter in the stems of low plants, and the former in bur- rows of other larvae or under bark of trees. The larva of Aphrosylus occurs among seaweed on the shore. HABITS OF IMAGINES Many of the species occur upon flowers, and several genera, such as Chrysotus, Dolichopus, and Psilopus occur commonly upon leaves of plants. They undoubtedly feed upon nectar, but even Psilopus will destroy small insects, as I have seen it catch a small thrips, and though it did not kill it, its actions were such that I am convinced that the species are predaceous. Medetcrus I have seen feeding upon a specimen of Forcipomyia. Aphrosylus I know from observation to be predaceous, and Hydrophorus and Campsicnemus have the same habit. NOTES ON DESCRIBED SPECIES The only identified species that has been recognizably described from North America is Thrypticus nuthlenbergiae Johannsen and Crosby. From an examination of the figures and description of the larva of this species I find that it agrees with that of T. smaragdinus Gerstaeker, a European species, in being peripneustic, and in having a transverse band of locomotor spinules on 8 of the ventral segments, the spinules of the anterior series of each band stronger than those of the 2 or more posterior series. The general shape of the European larva is more uniform than that in the figure of the American, but I suspect that the latter represents a specimen just prior to pupation. The cephalic capsule of the pupa of both species is armed with a pair of protuberances, those of smaragdinus being strong and stout, while 405 those of muhlenbergiae are slender and almost hair-like. The thoracic respiratory organs in both species are stalk-like. The figure and de- scription of our species give us no details of the legs and wings, but smaragdinus is figured as having the wings extending to the apex of second abdominal segment, the apices of fore tarsi to middle of fourth, those of mid tarsi to apex of fifth, and those of hind tarsi al- most to apex of abdomen. Both species have a single transverse series of short spines on each dorsal abdominal segment, and peduncu- late spiracles on lateral margins of segments 1 to 4. The apical seg- ment in muhlenbergiae is armed with 4 thorns. It will be seen from the foregoing that the pupae offer as charac- ters for distinguishing them from the pupae of Drapetis the peduncu- late abdominal spiracles and the single transverse series of dorsal ab- dominal spinules. The larvae I can not fully compare because I have only a cast larval skin of Drapetis which affords no evidence as to whether there are lateral abdominal spiracles in that stage. The loco- motor spines differ somewhat, however, and if the figure of muhlen- bergiae is dependable the head also differs in having a single saddle- like dorsal plate. Both species of Thrypticus above mentioned live in stems of plants; neither species forms a cocoon like that of Drapetis. Medeterus lives in burrows of wood-boring larvae and also under bark. .Dr. E. P. Felt has recorded the larvae as feeding upon those of Miastor. No species of this genus has been described in either the larval or pupal stage from America. Perris has described the larva and pupa of Medeterus ambiguus, a European species. The larva of this species has the head very similar to that figured in the present paper for Drapetis (Pl. LVI, Fig. 6). The distinctions, judging from Perris’s figures, lie in the presence of only one series of locomo- tor spinules on the abdominal segments, and in the tapering apical ab- dominal segment, which ends in 4 short subcontiguous points, at the apices of the upper and larger pair of which are located the posterior spiracles. No mention is made of lateral abdominal spiracles, but the prothoracic pair are figured. . The pupa has the pair of cephalic spines similar to those of Thrypticus, but slightly ventrad of them are 2 much smaller protuberances. The thoracic respiratory organs are long and slender. The fore tarsi do not extend beyond apices of wings, the mid pair reach middle of fourth abdominal segment, and the hind pair extend to middle of sixth. The dorsal abdominal seg- ments possess 2 linear transverse series of spinules. A species of Systenus described by Laboulbéne differs in the larval stage from Medeterus in having the locomotor spinules situated upon 406 ventral fusiform transverse areas, and in the shape of the apical seg- ment, the latter being of uniform width to apex, and having 4 short, widely separated protuberances, the lower pair distinctly longer than the upper, the latter bearing the posterior spiracles. The pupa of this genus resembles closely that of Medeterus, but the thoracic respiratory organs are figured as long as head and thorax together, with distinctly tapered apices. The fore tarsi extend be- yond the apices of the wings and the dorsal abdominal segments each have a band of locomotor spinules consisting of about 3 series, the anterior one of which is much stronger than the others. Neither Medeterus nor Systenus has the abdominal spiracles pedunculate. Brauer figures the larva of Dolichopus aeneus De Geer. The head shows an upper T-shaped piece whose anterior portion is considered as the labrum, and on each side of this plate are the sickle-shaped mandibles; the maxillae are not chitinized and their palpi are short and blunt; the antennae consist of 2 joints. The posterior cephalic rods are represented as slender, the upper pair slightly broadened pos- teriorly and exceeding in length the lower pair. The body is figured with 7 pairs of pseudopods, the apices of which are armed with rather strong spinules. The apical segment terminates in 4 short subequal protuberances. The pupa has the cephalic capsule with 4 small warts above, and below these 2 others. The thoracic respiratory organs are very long and slender. : The larva of a species of Dolichopus is figured herein (PI. LVII, Fig. 3). This is Larva (b) of C. A. Hart’s paper previously referred to, which he described at the conclusion of the part dealing with Brachycera. All three species therein referred to are of this genus. REFERENCES TO PAPERS ON THE BroLoGy or NortH AMERICAN AND EurRorEAN DOLICHOPODIDAE Brauer, F. Denschr. k. Akad. Wissensch., Wien, math.-naturw. Cl., 47: 44. (1883) Felt, E. P. Jour. Eeonom. Ent., 4: 414. (1911); Can. Ent., 45:373. (1913) Grinberg, K. : Die Siisswasserfauna Deutschlands, Heft 2a, Erster Teil, p. 167. (1910) 407 Hart, C. A. Bull. Ill. State Lab. Nat. Hist., Art. VI, 4:268-270. (1895) [Larvae (a), (b), and (c), described without assigning them to any family, belong to the Dolichopodidae. | Johannsen, O. A., and Crosby, C. R. Psyche, 20:164. (1913) Laboulbéne, A. Ann. Soe. Ent. France, ser. 5, 3:49. (1873) Perris, E. : Ann. Soe. Ent. France, ser. 4, 10:321. (1870) Wheeler, W. M. Proe. Calif. Acad. Sci., ser. 3, 1:150. (1897) Urbana, Illinois, March 16, 1917, (To genera and species described or discussed separately or in family connection, or included in the synoptic keys.) Anastoechus nitidulus, 393. Aphoebantus mus, 392. Argyramoeba oedipus, 392. Asilus, 385. notatus, 385. sericeus, 386. Atherix, 364. Bezzia, 284. Bibio, 299. Bibiocephala, 275. Bittacomorpha clavipes, 239. Bolitophila, 248. cinerea, 248. disjuncta, 248. hybrida, 248. montana, 248. Bombylius, 392. Camptocladius, 288, 289. Ceratopogon, 283. Ceraturgus cruciatus, 379. Ceroplatus, 261. Chironomus, 288, 289. Chrysanthrax fulvohirta, 392. Chrysopila, 364. foeda, 367. ornata, 365. quadrata, 367. Chrysops, 357. Coenomyia pallida, 353. Corynoneura, 288. Cricotopus, 288, 289. Culicoides, 283. Cylindrotoma, 211. Dasyllis, 380. Deromyia, 384. discolor, 384. winthemi, 376. Diamesa, 289. Dicranomyia simulans, 213. Dicranota, 219. bimaculata, 219. Drapetis nigra, 403. Elliptera omissa, 226. Epiphragma, 224, fascipennis, 224. Erax aestuans, 388. maculatus, 387. Eriocera, 233. Erioptera, 231. Euforecipomyia, 283. Eupachygaster, 336. henshawi, 338. punctifer, 338. _Exechia, 254. nativa, 255. Exoprosopa fasciata, 393. fascipennis, 393. Foreipomyia, 283. Geosargus, 332. viridis, 333. Gnophomyia, 230. tristissima, 230. Goniops, 356. -Hartomyia, 284. Helobia punctipennis, 229. Hermetia, 323. illucens, 323. Heteromyia, 284. Hexatoma, 233. Hyalanthrax alternata, 393. hypomelas, 393. lateralis, 393. Johannsenomyia, 284. Laphria, 375. . Leia, 252. oblectabilis, 253. Leptis, 367. Leptogaster flavipes, 377. Limnobia, 214. immatura, 216, triocellata, 215. Limnophila, 221. luteipennis, 222. tenuipes, 223. Liogma, 211. Maurina californiensis, 266. Metriocnemus, 288, 289, 290. Microchrysa, 334. polita, 334, Monardia sp., 296. Mycetobia, 242. divergens, 244. Mycoma brevivittata, 257. Mydas clavatus, 372. Nemotelus, 324. Neoceratopogon, 283. Neopachygaster, 335. maculicornis, 336. Odontomyia, 320. eincta, 321. vertebrata, 321. Olbiogaster, 242. Orphnephila, 290. testacea, 290, 291. Orthocladius, 289, 290. Oxycera, 324. albovittata, 330. aldrichi, 329. approximata, 326. centralis, 326. erotchi, 328. picta, 331. variegata, 327. Pachyrrhina, 196. ferruginea, 206. Palaeoplatyura, 248. aldrichi, 248. johnsoni, 248. Palpomyia, 284. Parabezzia, 284. Pedicia, 218. albivitta, 218. Penthoptera, 232, 233. Phalacrocera, 211. Plecia, 299. Polylepta, 256. leptogaster, 257. Probezzia, 284. Proctacanthus milberti, 377, 385. philadelphicus, 377, 385. Promachus, 383. fitchii, 383. vertebratus, 375, 376. Pseudobezzia, 284. Psilocephala haemorrhoidalis, 397. melampodia, 398. Psychoda albimaculata, 272. alternata, 267, cinerea, 271. domestica, 271. floridica, 267. minuta, 268. nocturnala, 267. sehizura, 267. superba, 269. Ptychoptera sp., 240. Retinodiplosis pini-inops, 295. Rhabdophaga podagrae, 296. Rhaphidolabis, 220. 409 Rhamphomyia dimidiata, 401. Rhegmoclema atrata, 301. Rhyphus, 242. punctatus, 243. Scenopinus fenestralis, 399. Sciara, 258. Serromyia, 284. Simulium, 302. Sparnopolius fulvus, 393. Spogostylum albofasciatum, 395. anale, 392. simson, 393. Stratiomyia, 318. meigeni, 320. norma, 319. Symphoromyia, 363, 364. Systoechus oreas, 393. Tabanus, 358. atratus, 359, 360. carolinensis, 360. costalis, 359, 360. epistates, 360. lasiophthalmus, 360. lineola, 359, 360. nigrescens, 359, 361. , stygius, 359, 361. Tanytarsus, 288, 289. Thalassomyia, 289. Tipula, 196. abdominalis, 200. bicornis, 205. cunctans, 204. eluta, 203. serta, 205. trivittata, 204. Toxophora virgata, 393. Trichocera, 234. Triogma, 211. Ula, 225. elegans, 225. Xiphura, 194. fumipennis, 195. Xylomyia, 340. americana, 341, 343. aterrima, 341, 343. pallidifemur, 343. pallipes, 342. parens, 341, 343. tenthredinoides, 342, 344. Xylophagus abdominalis, 351. decorus, 348. fasciatus, 348. gracilis, 348. longicornis, 348. lugens, 349. reflectens, 348, rufipes, 348. Zabrachia, 340. polita, 340. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. SoOWADN Bw DE alll eed = ow bo =a" oe [alll aeolll seed onxna Puate XXVIII Larvae and Pupae of Tipulidae and Limnobiidae Tipula eluta, larva, lateral view. Tipula sp. 2, larva, lateral view. . The same, larva, caudal view of apical segment. . Pachyrrhina ferruginea, larva, lateral view of female. . The same, pupa, dorsal view of apical segment of female. . The same, pupa, lateral view. . Tipula bicornis, pupa, lateral view of apical segment of male. Tipula serta?, pupa, lateral view of apical segment of female. Tipula eluta, pupa, lateral view. Pachyrrhina ferruginea, pupa, lateral view of apical segment of male. . Tipula eluta, pupa, lateral view of apical segment of male. . Pachyrrhina ferruginea, pupa, palpus. . Tipula eluta, pupa, ventral view of head, thorax, and base of abdomen. . Tipula sp. 1, pupa, lateral view. . Gnophomyia tristissima, pupa, ventral view of head, thorax, and base of abdomen. . The same, pupa, ventral view of apical segment of male. . The same, pupa, dorsal view of apical 2 segments of male. . The same, pupa, ventral view of apical segment of female. Prate XXXVI PLATE XXIX Larvae and Pupae of Tipulidae and Limnobiidae Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. ip Co I OR 09 bo Tipula eluta, larva, dorsal view. The same, pupa, dorsal view. Tipula sp. 5, larva, dorsal view. Limnophila luteipennis, larva, dorsal view. The same, pupa, dorsal view. Helobia punctipennis, larva, dorsal view. The same, pupa, dorsal view. Genus incertus 3, larva, dorsal view. PLATE XXIX bak Ed isionii bank hind cvemmma ; Puate XXX Larvae and Pupae of Tipulidae, Limnobiidae, and Ptychopteridae . Limnophila luteipennis, larva, dorsal view of apical segment. . Bittacomorpha clavipes, larval pseudopod. . Pachyrrhina ferruginea, larva, apical segment. . Bittacomorpha clavipes, larva, lateral view. . Genus incertus 3, larva, apical segment. . Bittacomorpha clavipes, pupa, dorsal view. dee de dS" de" de aor WD eH PLATE XXX PuaTE XXXI Larvae of Tipula fod Tipula sp. 7, caudal view of apical segment. The same, dorsal view of head, one side. The same, ventral view of head, one side. . Tipula sp. 4, dorsal view ot fronto-clypeal region of head and antennae. The same, caudal view of apical segment. Tipula sp. 6, dorsal view of apical segment. The same, caudal view of apical segment. Tipula sp. 1, eaudal view of apical segment. Tipula sp. 2, frontal plate of head. Pachyrrhina ferruginea, frontal plate of head. Tipula sp. 7, lateral view of hypopharynx, showing oesophageal opening. . Tipula sp. 3, dorsal view of hypopharynx. . Tipula sp. 2, dorsal view of hypopharynx. . Tipula sp. 7, dorsal view of hypopharynx. Tipula sp. 4, dorsal view of hypopharynx. PLATE XXXI PLaTE XXXII Larvae and Pupae of Tipulidae Tipula sp. 1, hypopharynx of larva, dorsal view. The same, mandible of larva. The same, labium of larva. Tipula sp. 3, side view of protruded portion of head of larva: a, antenna; p, maxillary palpus; m, mandible; J, labium; fp, frontal plate. Tipula sp. 2, labium of larva. Tipula sp. 3, labium of larva. Tipula sp. 5, apical segment of larva, lateral view. The same, apical segment of larva, caudal view. Tipula sp. 4, labium of larva. Tipula cunctans, labiam of larva. . The same, outline of anterior margin of hypopharynx of larva. 2. Tipula bicornis, labiam of larva. The same, outline of anterior margin of hypopharynx of larva. Pachyrrhina ferruginea, labium of larva. The same, outline of anterior margin of hypopharynx of larva. Tipula trivittata, apical segment of male pupa, lateral view. The same, apical segment of female pupa, lateral view. = Tipula sp. 7, apical segment of female pupa, lateral view. Tipula cunctans, apical segment of female pupa, lateral view. . Niphura fumipennis, thoracic respiratory organ of pupa. The same, antenna of larva. Tipula cunctans, apex of male pupa, lateral view. Xiphura fumipennis, hypopharynx of larva, dorsal view. The same, pupa, dorsal view. The same, mandible of larva. Tipula sp. 4, mandible of larva. Tipula sp. 7, mandible of larva. PLATE XXXII as re 2 “et Vives, Hig, 2: Fig. 3. Fig. 4 Fig. 5 Fig. 6 Ie 7 Fig. 8. intves, 2): Fig. 10. Fig. 11. Fig. 12. Fig. 13. Fig. 14. Fig. 15. Fig. 16. Fig. 17. Fig. 18. Puate XXXIIT Larvae and Pupae of Limnobiidae Phalacrocera replicata, larva, dorsal view. Limnophila luteipennis, antenna of larva. The same, labium of larva. . Phalacrocera replicata, pupa, lateral view. . Dicranomyia simulans, thoracic respiratory organ of pupa. . Limnobia triocellata, mandible of larva. ‘Limnophila luteipennis, head of larva, dorsal view. Limnophila tenuipes, apical segment of male pupa. The same, apical segment of female pupa. Limnobia triocellata, apical segment of larva, lateral view. Limnobia immatura, side view of pupal exuvium. The same, dorsal view of apical segment of pupal exuvium. Limnobia triocellata, larva, lateral view. Limnobia immatura, thoracic respiratory organ of pupa. Limnophila luteipennis, mandible of larva. Limnobia triocellata, head of larva, dorsal view. The same, head of larva, ventral view. Limnophila luteipennis, thoracic respiratory organ of pupa. Prate XXXII Puatre XXXIV Larvae and Pupae of Limnobiridae Limnobia immatura, face of pupa, seen from above. Limnobia triocellata, face of pupa, seen from above. The same, apical segment of pupa, dorsal view. The same, apical segment of pupa, lateral view. Dicranota sp., maxillary palpus of larva. The same, antenna of larva. The same, larva, lateral view. Genus incertus 2, larva, lateral view. Dicranota sp., head of larva, dorsal view. Gnophomyia tristissima, head of larva, dorsal view. Helobia punctipennis, mandible of larva. Penthoptera sp., head of larva, dorsal view. The same, apical segment of larva, dorsal view. The same, larva, lateral view. Genus incertus, 2, apical segment of larva, dorsal view. Grophomyia tristissima, apical segment of larva, caudal view. Helobia punctipeninis, apical segment of larva, caudal view. The same, head of larva, dorsal view. Genus incertus 3, head of larva, dorsal view. PLATE XXXIV Fig. Fig. Fig. Fig. Fig. Fig. Fie. Fig. Fig. Fig. Fie. Fig. mila Fig. Fie. Fig Fie PLATE XXXV Larvae and Pupae of Limnobiidae and Ptychopteridae Genus incertus 2, head of larva, dorsal view. Epiphragma fascipennis, larva, lateral view. (After Needham.) The same, apical segment of larva, dorsal view. (After Need- ham.) Genus incertus 2, head of larva, ventral view. Bittacomorpha clavipes, head of larva, dorsal view of one half. The same, head and thorax of pupa, ventral view. Ptychoptera sp.?, head of larva, dorsal view of one half: a, antenna; e, eye; 1, labrum; m, mandible. . Bittacomorpha clavipes, head of larva, ventral view of one half. . Epiphragma fascipennis, pupa, ventral view. (After Needham.) . Ptychoptera sp., head of larva, ventral view of one half: e, epi- pharynx; m, mandible; a, antenna; mp, maxillary palpus; J, labium. Genus incertus 1, larva, lateral view. . Ptychoptera sp.?, larva, lateral view. Genus imceertus 1, apical segment of larva, dorsal view. . The same, locomotor organ of larva. 15} 3 Ifo). Bittacomorpha clavipes, mandible of larva. Genus incertus 1, ventral view of head of larva. Prats XXXV YY / PLATE XXXVI Larva of Limnobiidae and Larvae and Pupae of Rhyphidae Wes Al Fig. : 2. Big, 3: Fig. 4. Fig. 5 Fig. 6 Fig. 7. 1iikee to}. Fig. 9 Fig. 10 Fig. 11 Fig. 12 Trichocera sp.?, larva, dorsal view. Rhyphus punctatus, apical segment of larva, lateral view. - Mycetobia divergens, larva, lateral view. Rhyphus punctatus, head of larva, dorsal view. The same, mandible of larva. . Mycetobia divergens, head, thorax, and base of abdomen of pupa, ventral view. The same, head and thorax of pupa, dorsal view. The same, head, thorax, and base of abdomen of pupa, lateral view. . Rhyphus punctatus, head, thorax, and base of abdomen of pupa, lateral view. Trichocera sp.?, labium, maxilla, and mandible of larva, ven- tral view. . Mycetobia divergens, labium, maxilla, and mandible of larva, ventral view. . Rhyphus punctatus, labium and maxillae of larva, ventral view. PLATE XXXVI L = | se oe 09 ae = | oie SPSS) ee) Sher) alle ee) IS) PLATE XXXVII Larvae and Pupae of Mycetophilidae Leia oblectabilis, head of larva, dorsal view (punctures not drawn). Exechia nativa, locomotor spinules of larva. The-same, larva, lateral view. The same, prothoracic spiracle of larva. Leia oblectabilis, pupa, lateral view. Erechia nativa, mandible of larva. The same, head of larva, dorsal view. Leia oblectabilis, hypopharynx of larva. Berechia nativa, maxilla of larva; p, maxillary palpus. Leia oblectabilis, mandible of larva. Exechia nativa, hypopharynx of larva. . The same, pupa, lateral view; a, larval head and skin. . Leia oblectabilis, maxilla of larva; p, maxillary palpus. . The same, head of larva, ventral view: 0, eye (—pellucid spot ventrad of antenna); m, mandible; mz, maxilla; h, hypo- pharynx. Exechia nativa, illustrating effect of parasitism upon pupa; a, larval head and skin. Polylepta leptogaster, mandible of larva. (After Schmitz.) . Mycoma brevivittata, mandible of larva. . The same, pupa, lateral view. PLATE XXXVII Fig. bo Puatr XXXVITII Larvae and Pupae of Mycetophilidae, Sciaridae, and Platyuridae Mycoma brevivittata, ventral aspect of head and thorax of pupa: A, antenna; P, palpus; 7, coxa, 2, femur, 3, tibia, 4, tarsus of fore leg; Za, coxa of mid leg; 4a, tarsus of mid lee; W, wing. Sciara prolifica, head of larva, ventral view: Ja, labium; a, an- tenna; mz, maxilla; mp, maxillary palpus; m, mandibles; lb, labrum. Polylepta leptogaster, head of larva, ventral view: parts figured and lettering as for Figure 2. (After Schmitz.) Mycoma brevivittata, head of larva, ventral view: parts figured and lettering as for Figure 2. Sciara prolifica, ventral aspect of head and thorax of pupa: parts figured and lettering as for Figure 1. Sciara sp.?, head of larva, dorsal view. Sciara prolifica, pupa, lateral view. Ceroplatus sp.?, maxilla of larva. Sciara sp.?, dorsal sclerite of head of larva, and the hypophar- ynx. Ceroplatus sp.?, head of larva, dorsal view. The same, head of larva, ventral view: a, antenna; /b, labrum: m, mandible; mx, maxilla; Ja, labium. The same, mandible of larva. The same, apical segment of larva, dorsal view, showing trachea- tion. Sciara sp.?, mandible of larva. Ceroplatus sp.?, head of larva, front view: parts figured and lettering—with the addition of 0, eye—as for Figure 1. The same, pupa, lateral view. PrAte XXXVIII Fig. Fig. Fig. Fig. Fig. Fig. Fig. Whe, Fie. Hie. Fig. Fig. Fig. Fie. Fig. Fig. Fig. Fig. PLaTE XXXIX Larvae and Pupae of Psychodidae Psychoda minuta, ventral view of apical segment of pupa. Psychoda superba, lateral view of apical segment of pupa. Psychoda cinerea, lateral view of apical segment of pupa. . Psychoda superba, apical armature of second dorsal abdominal segment of pupa. . Psychoda minuta, thoracie respiratory organ of pupa. . Psychoda superba, thoracic respiratory organ of pupa: (a, small opening in surface; b, portion showing the surface reticula- tion. . Psychoda minuta, dorsal view of larva. . > Psychoda superba, plates of second dorsal abdominal segment. Psychoda minuta, lateral view of apical segment of larva. . Psychoda superba, ventral view of pupa. . Psychoda cinerea, dorsal view of larva. . Psychoda superba, antenna of larva. . The same, dorsal view of larva. . Psychoda sp.?, dorsal view of larva. . Psychoda superba, lateral view of apical segment of larva. . Psychoda minuta, head of pupa: a, antenna; e, eye; c, clypeus; p, palpi; f, tibia. . The same, dorsal view of second abdominal segment of pupa. . The same, ventral view of third abdominal segment of pupa. PLATE XXXIX Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. TUS oS 9 PO PuatE XL - Larvae and Pupae of Blepharoceridae, Culicidae, and Divridae Bibiocephala sp.?, larva, dorsal view. The same, pupa, ventral view. Culex restwans, larva, dorsal view. Bibiocephala sp.?, pupa, lateral view. . Dixa sp.?, larva, lateral view. Bibiocephala sp.?, thoracie respiratory organ of pupa. . Dixa sp.?, pupa, lateral view. 8. Culex restwans, pupa, lateral view. PLATE XL Fig. Fig. Fig. Fig. Fig. Fie. Fig. Fig. Fig. Fig. | Fig. Fig. Fig. Fig. Fig. Fig. Fig. oom Puate XLI Larvae and Pupae of Culicidae, Dixidae, Ceratopogomdae, and Chironomidae . Sayomyia americana, head of larva, lateral view. The same, larva, lateral view. . Dixa sp.?, labium of larva. Camptocladius byssinus, antenna of larva. . Dira sp.?, head of larva, dorsal view: A, antenna; B, labrum; C, epipharynx ; D, maxillary palpus; 2, mandible; /, maxil- lary lobe or mouth-brush. Forcipomyia cilipes, dorso-lateral bristle of larva. Ceratopogon fusculus, dorsal abdominal bristle of pupa. . Forcipomyia specularis, dorsal bristle of larva, side view. The same, dorsal bristle of larva, front view. Forcipomyia cilipes, dorsal bristle of larva, front view. . Forcipomyia pergandei?, antenna of larva. . Camptocladius byssinus, apical segment of larva, ventral view. . Palpomyia longipennis, mandible of larva. . Forcipomyia specularis, mandible of larva. . The same, head of larva, lateral view. . Camptocladius byssinus, larva, lateral view. . The same, prothoracie pseudopod of larva, lateral view.
  • aoe Cua) Mf = ” { -, ; i - a } h ‘* veer tee AT ET Pattie pee tet nape Saath erie . - . a x P (has ae B - aw cB Daft, AES at Prete fs ‘a Nya yo Py ah tne ' as a a ag tpt chili Mv eertinldine: Dope BODO Joris DOGO SCPC HI eoooE 450 Phylogenetic comparison of Zygoptera and Anisoptera...............-. 453 ESSINGTON, SEE ae cocoa gob oben Han Ca GCS OO0LD HOGTO CROAC TOO OM Orion 464-577 Dhaai iy AV ennori rahe hore Or eng Noe BED One Am nod Dec UrFCGDOGr OCOD 466 RUE ee strnat yaee NOL TONITELO cn yes Be Avan! acest iehegel et oythciave as tals \e exnisusyauat ol eibjvi< ara ao 466 TIVE VN ORTLA OT LOU UCAS ata a/efeie s/o i8) a axsieteis o/oie iaplaiereiseusioie (alley sie) so) aievere steels e/aile 476 Subfamilies :— MCR TAYESLE Ey atare: acclel aves cofalatsta)a spel she Grelalecsi aisles ots cts-ais) 3ie\a)s Seis e's sce. etzsare, 2 9y 477 MU EIESTrA OTN TELTECACS Maver at ots eke [eat fare eye 2 aot is ayarehn6|Gre\e) ols) same ai dye Sines, 499 TTL FA Cia 6 Oi Gcib CDS GU OnEICoICY CEE acto CE nee Tee or ae cea 577 ase ECMP MEL Aas RDPCIOS stad crete. arstateiats ls ste cies teria. Shots oi class aie 2/ocaraibie areie''s 584 Aubreviations wsed, mulettering plates... ./(. 52006 ls ciae acide Vr esiece's cea cient 586 ArticLe IV.—The Zygoptera, or Damsel-flies, of Illinois.* By Puiir GARMAN, PH.D. INTRODUCTION The order Odonata includes all insects known as dragon-flies in the broad sense of the term. ‘The adults are characterized by the possession of four membranous, net-veined wings which are of nearly equal size. The mouth-parts are fitted for biting and the metamor- phosis is incomplete. The males are distinguished by accessory gen- italia on the second and third abdominal sterna. ‘The nymphs are aquatic, and are recognizable and separable from other aquatic forms by the large hinge-like labium which folds beneath the head. The order is subdivided into two suborders, the Anisoptera and the Zygoptera. The adults of the Anisoptera have large, broad wings, but little contracted at the base and with numerous cross-veins. ‘The wings of the Zygoptera are usually narrowed at the base and possess fewer cross-veins. The Anisoptera usually rest with wings spread horizontally ; the Zygoptera usually with wings held vertically. The nymphs of the suborders are easily separated by means of the respira- tory apparatus, the Zygoptera having three tracheal gills at the caudal end of the abdomen, and the Anisoptera having no caudal tracheal gills, being provided with rectal gills instead. The Odonata form one of the strangest orders of insects with which an entomologist has to deal. Their bizarre form, striking colors, and peculiar habits make them an object of much curiosity on the part of the layman as well as the object of many studies on the part of the scientist. The prevalence of the popular terms, snake-feeders, snake- doctors, and similar names, shows that there are many superstitions concerning the group. As is well known, the Odonata are predaceous, in all stages, upon other insects, particularly upon those insects annoying to man, the flies and mosquitoes, and in this role they must be classed as beneficial. Their harmful activities are few, but they sometimes destroy young fish, they occasionally injure plants by the insertion of eggs, and, ae from the Entomological Laboratories of the University of Dlinois 0. 53. 412 most serious of all, they do not discriminate between beneficial and noxious insects, but destroy both. An instance of the fact last men- tioned is the recently reported feeding of Anax junius on the honey- bee. In no case, however, is it probable that the harm done overbal- ances, or begins to counterbalance, the good which these insects do in the destruction of biting Diptera. The classification of the nymphs of Zygoptera is in a backward state as compared with the classification of the adults. This is due - especially to the fact that immature forms are not easily collected and that their classification is particularly difficult. An intensive study of the nymphal characters has shown that there are, within certain genera, groups of nymphs the species of which are much more closely related to each other than to the members of other groups of the same genus. These groups correspond to groups of adult species in the identification of which the characters of the anal appendages of the male are mostly relied upon. Little attention seems to have been given by taxonomists to the females, and where species are represented in collections by females only it is exceedingly difficult to determine them. Again, when studying nymphs, one is often successful in rearing a number of females, but almost any amount of painstaking work may fail to produce a male. In such cases still more inconvenience is experienced when it is found that the reared females can not be named because of the fact that the published synopses are based largely upon male characters. It is with a view to clearing up some of the obscure features of the classification and lessening the labor of determination that nymphs and adults, including both sexes, have been considered together and tables prepared for the separation of both. All obtainable biological data have been added for the sake of com- pleteness; but it is fully realized that the data given here are incom- plete, and can only be made complete after many years of diligent study. Nymphs of several species which are apparently new have been reared in the course of the study and are described herein for the first time. Some of the remaining species which doubtless occur in Illinois but which have not been collected by the writer, have been obtained through the courtesy of various people, and the list has been completed as far as possible in this way. Certain problems concerned with the nomenclature have presented themselves, the most important of which concerns the adoption of family names. According to the ruling of the International Commis- sion on Zoological Nomenclature (Muttkowski, ’10: 15) Agrion re- 413 places Calopteryx, and the family name Calopterygidae must be abol- ished. The change has caused much confusion because of the former application of the name Agrionidae ; but it seems practically certain that further change would only result in still greater confusion, and the family names as used by Muttkowski are, therefore, adopted without change. : The use of the common names “dragon-fly”’ and “‘damsel-fly”’ in referring to the Anisoptera and Zygoptera respectively, causes no little confusion because of the frequent use of the term dragon-fly to denote the order as a whole. In the following pages, the words Anisoptera and Zygoptera will be used exclusively to designate the subdivisions of the order. ACKNOWLEDGMENTS I take pleasure at this point in expressing thanks for the valuable aid which Dr. A. D. MacGillivray has given by his careful supervision of work and thoughtful criticism during the course of the study. Thanks are also due to Dr. S. A. Forbes for granting financial support from the funds of the Illinois State Laboratory of Natural History as well as for the loan of the collection of Zygoptera belonging to that laboratory. I am especially indebted to Mr. E. B. Williamson for his kindness in permitting me to examine his collection of Odonata; and I further wish to thank Dr. E.. M. Walker and Dr. J. G. Needham for the loan of specimens of zygopterous nymphs, and Dr. P. P. Cal- vert for the identification of material sent him. MorpPHOLOGY NYMPH The nymphs are distinguishable from all other insects by the possession of three more or less flattened, caudal, tracheal gills. They are slender, delicate insects of the same color as the surrounding veg- etation or environment in which they live and at first sight seem hardly capable of the predatory habits of the order. ‘They are usually covered with fine hairs or spinules which collect an ambuscade of dirt and rubbish. heir slender cylindrical abdomens resemble the stems of plants and weeds, and the caudal gills remind one frequently of growths of algae. Such adaptations as these render the insect most inconspicuous in its natural habitat. Head.—The head of the nymph is somewhat oval or pentagonal in outline when viewed from above, and is usually longer than wide. The sutures are indistinct even in full-grown nymphs with the excep- 414 tion of the epicranial suture, which is a Y-shaped line on the dorsum of the head, near the caudal margin. Sutures are wanting, separating vertex from occiput, occiput from postgenae, and postgenae from genae. ‘The vertex occupies that part of the dorsum of the head cap- sule caudad of the arms of the Y; and the occiput and postgenae together, the portion of the caudal aspect of the head not occupied by the occipital foramen and the compound eyes. The genae are the areas mesad of the ventral margins of the compound eyes. They fuse with _ the postgenae (Fig. 7, pg) near the ventral margin of the head. Extending caudo-dorsad on the caudal aspect from the ventral articu- | lations of each mandible, there is a distinct ridge which disappears near the middle of the head. The trochantins of the mandibles are present as indistinct triangular areas laterad of the bases of the mandi- bles (Fig. 7, tm). Compound Eyes.—The compound eyes of the nymphs, like those of the adult, are very large. They occupy perhaps one-third of the dorsal surface of the head, nearly the whole of the lateral surface, and part of the ventral. The facets are hexagonal and similar to those of other insects. Ocelli—The ocelli are wanting during nymphal life, but in the later stages the adult ocelli may be seen through the transparent cuticle of the dorstim of the head. ‘hus it often appears as if the nymph had ocelli when in reality there are none present, as can be proved by an examination of the final exuvium, or by dissection. Antennae.—The antennae, in all full-grown nymphs, consist of seven segments. The distal segment is short in most species and the connection between it and the preceding one is frequently obscure, so that it seems as if the appendage had only six segments. The first segment is usually thicker than the remaining ones, and in the Agrionidae is as long as all the rest of the segments together. In the Coenagrionidae, the third segment is the longest and each of the seg- ments distad of it is shorter than the segment preceding. The two proximal ones are not constant in length but are always shorter than the third. Mandibles—The mandibles are normally hidden from sight by the large labium and the flap-like labrum. They are located on the ventral surface of the head and are well formed for mastication. They are irregular in outline, though somewhat rectangular, bearing four short, strong teeth along the distal margin and several smaller teeth mesad and proximad of these. Mavxillae.—The maxillae (Fig. 22) are attached to the ventral surface of the head and the following parts are distinguishable: a 415 triangular cardo (cd) ; a narrow sclerite which may be known as the cardella (cl); and a long, oblong stipes, to the distal end of which are attached two appendages representing palpus, lacinia, and galea. The lateral, narrower one of these (mxp), the palpus, bears on its surface a number of strong setae. There is sometimes a distinct swell- ing at the base of it but there is no distinct suture between the proximal and distal portions. The remaining process, regarded as the fused galea and lacinia (glc), is much broader at the base and tapers con- siderably at the apex, where it bears about five strong hooks. It is provided with two rows of weaker setae extending proximad from the hooks. The identification of this piece as fused galea and lacinia is due to the supposed occurrence, in adults of certain species, of a suture extending across it from the proximal to the distal end. So far no case has come to my notice in which this suture is present, but a study of Ephemerida (Morgan, ’13) and Plecoptera (Fig. 31) on the other hand, proves conclusively that the piece has been correctly inter- preted. Labium.—The labium differs greatly from that of the ordinary insect in being free from the head at the point of articulation of the submentum, and in being folded so that mentum and submentum are approximated when the piece is at rest. It is applied to the ventral surface of the head, forming a sort of mask; and an idea of its general location and shape may be obtained from Figures 1-4, 6, and 7. Several forms of labia occur in the suborder which, although sim- ilar in general construction, differ in certain particulars. The forms of the lateral arms or labial palpi, the mentum, and the submentum are different enough in different species to enable one to determine the family, and sometimes the genus, at a glance (Figs. 8-13). The sub- mentum is a hollow tube of cuticle (Figs, 2, 4; sm) articulating at its proximal angles with the ventral wall of the head capsule. It is filled with muscles for the extension and retraction of tlhe labium as a whole, and varies in shape from cylindrical to flat, and from comparatively short, hardly extending caudad ol the posterior margin of the head, to long and slender, reach- ing caudad of the metacoxae. The mentum-ligula, or median lobe (Figs. 8, 9; ml), is likewise filled with heavy muscles which move the labial palpi. It varies in shape, in the degree of the con- traction proximad, and, more important for purposes of classification, in the number of mental setae (Figs. 10, 12, 13; ms). The median lobe is sometimes notched or cleft at the apex but is more frequently with- out indentation. The glossae and paraglossae are present at the distal end of the labium, but the suture between them and the mentum is in 416 most cases indistinct. The latter, however, seems to be represented in species having the deeper median clefts. The palpi are present in the so-called “lateral arms”, the distal segments being represented by the movable hooks (Figs. 8, 9; lp.). The lateral arms also bear.a number of raptorial setae in some species (Fig. 10). In capturing prey,.which consists of mosquito and other soft aquatic larvae, the nymph swings out the hinged labium, opening and closing the lateral arms like a pair of jaws. The victim is then drawn back toward the- mouth and the heavy maxillae and mandibles finish the work. Labial Muscles—The muscles operating the labium have been. studied by few, and studies that have been made seem incomplete. It has therefore.seemed advisable to examine them in detail. The struc- tures have been determined by means of cross and longitudinal sections and verified as far as possible by gross dissections. The median lobe (Figs. 1, 2; ml) contains four large muscles for operating the lateral arms. These are attached proximad directly to the dorsal wall of the submentum, dorsad of the hinge (Fig. 4). At the point of attachment to the labial palpi, the muscles are usually modified to form tendons. With the submentum there are also two pairs of muscles, which, though not as large as those of the median lobe, play an even more important part in the operation of the piece. The points of insertion of the mental muscles are of especial interest and give clues to the actual function of each muscle. ‘The dorsal inner pair (Figs. 2, 4) is attached proximad to the tentorium and distad just above the hinge which is between the median lobe and the sub- mentum. ‘The remaining, or ventral, pair is attached to the chitinous ligament or rod described below—a structure present only. in the Odonata. The rod (Figs. 3, 4, 7; cr) is unpaired and is attached to the ventral wall of the head just caudad of the hypopharynx. It extends obliquely caudad and dorsad in the plane of the meson and is attached again to the dorsal wall of the submentum, at which point it expands in such a way as to form the top of a T. The ventral pair of muscles are inserted on the base of the chitinous rod (Fig. 4). From this point they extend over the mento-submental hinge and attach themselves to the ventral wall of the median lobe. A third pair of muscles, present at the base of the submentum, is attached to the ventral wall of the head caudad of the hypopharynx, extends caudad and dorsad, and is inserted on or near the tentorium. - The exact function of each of the muscles contained in the sub- mentum is difficult to explain, and it is probable that no single pair can be said to produce a given result with the exception of those operat- ing the labial palpi. Thus it can be seen that the oblique muscles at 417 the base of the labium are important in throwing the submentum away from the head. In this, however, they are aided by the presence of the oblique, chitinous rod and by the contraction of the dorso-sub- mental muscles. The action of the ventral pair seems reasonably clear, as it can, by contraction, swing the mentum back towards’ the sub- mentum, and by action in conjunction with the chitinous red, swing the submentum back towards the head. The mentum is swung out away from the submentum mainly by the action of the dorsal sub- mental muscles which are attached to it above the hinge and in this capacity are aided to some extent by the contraction of the muscles within the mentum, especially those which operate the labial palpi. Glossae and Paraglossae.—The glossae and paraglossae are fused and the suture is untraceable except in the embryo (Butler, ’04). ‘The nymph of Agrion shows a fold extending between the labial palpi beneath the median cleft. This fold probably represents all that is left of the suture between mentum and paraglossae. In other species the course of the suture is marked by a row of setae, the mental setae. The area occupied by the submentum is indefinite, but it is probable that the mental setae, even if secondary in origin and occurring only in the more specialized forms, are near the location of the original mento-paraglossal suture. The latter suture has been thought to become approximated to the distal border of the median lobe, but this seems doubtful after comparisons of nymphal and embryonic labia (Butler, ’04). Labial Palpt.—The palpi of the labium are represented by the lat- eral lobes, (Figs. 8, 9; lp,, lp»). These lobes bear at their distal ends a number of fixed hooks, which are simple in some cases, but may become modified in others, for instance in the Coenagrionidae, in which the middle hook is replaced by a blunt process with teeth at the apex. That the fixed hooks have not the same origin as the mov- able ones, is shown by the fact that the latter bear, in certain nymphs, a number of long setae. The movable hook has been considered (But- ler, 04) as a modified palpal segment, and this interpretation is un- doubtedly the correct one. The proximal segment or body of the lateral arms also bears in many species of nymphs a row of long setae, the number of which is used extensively in the classification of the group. In Agrion, however, this row of setae is wanting and the lat- eral lobe bears only two small setae near the base of the movable hook. The body of the mentum is also provided with rows of setae in all genera except Argia, Agrion, and Hetaerina, the bristles being in two divergent lines beginning near the meson slightly distad of the center and reaching nearly to the proximal end of the labial palpi. 418 Median Lobe.—This term is used for convenience and includes the fused glossae and paraglossae. Hypopharynx.—Perhaps the most conspicuous portion of the hypopharynx is a circular pad between the tips of the maxillae, and easily seen on raising the mentum-ligula. It is covered with minute setae possibly indicating the location of sensory organs. ‘The pad has been given the name laminula by Berlese, and corresponds to the lingua of other insects. However, it is somewhat difficult to homologize any part of it with other forms on account of the very great modification. — Propharynx.—The propharynx lies closely applied to the ental sur- face of the labrum, and has essentially the same shape as the latter. — It possesses no features worthy of mention. Prothorax.—The prothorax, the large segment just caudad of the head, is preceded by a smaller segment, the microthorax, which forms the neck. ‘The sclerites of the microthorax are not well developed in the nymph. Most of the sutures of the prothorax are also indistinct and are represented by furrows in the cuticle. The pronotum (Fig. 23, pme) is divided by depressions into caudal, mesal, and cephalic areas. ‘The caudal lobe is, in most species, a narrow transverse area along the caudal margin; the mesal lobe comprises the larger part of the pronotum, and is usually divided by a median furrow into two lateral areas; and the cephalic lobe includes the transverse area cephalad of the median lobes and caudad of the cephalic margin. The furrow which marks the caudal boundary of the cephalic lobe and the median furrow of the pronotum form a Y, and at the point of union of the three arms there is usually an invagination. The proepimera and proepisterna are areas ventrad of the pronotum on either side.and dorsad of the coxae, and are separated by furrows which are very dis- tinct in some genera, especially Lestes. In this genus the furrow sep- arating the two pieces extends dorsad a short distance from the point of articulation of the procoxae and the procoxal process (Fig. 25, pexp), bends slightly cephalad and then caudad, extending to the caudal margin of the prothorax. In the Coenagrioninae there is often a sec- ondary ridge extending dorsad from the procoxal process but this does not mark the boundary between proepisternum and proepimeron. The prosternum is the area between the procoxae, and is much broader than that of the adult. ‘There is no indication of distinct areas or sclerites, but near the caudal margin of the prosternum and between the coxae are the two invaginations of the furca (Fig. 24, fi). Mesothorax and Metathorax.—The mesothorax and metathorax are greatly different from the common type of thorax, in consequence of an approximation of the mesepisterna on the dorso-meson in the 419 mesothorax and an approximation of the epimera on the ventro-meson in the metathorax; all of which is accompanied by an enormous de- velopment of muscles within the thorax in preparation for the active life of the adult. The wing-cases, too, are early approximated, and there is a corresponding reduction in the size of the mesonotum and metanotum. Mesonotum.—The mesonotum is divided into two regions by the closing together of the mesepisterna. The cephalic one, the prescutum, just caudad of the pronotum, is a shield-shaped plate with slightly projecting cephalo-lateral angles. On the cephalic margin of this piece on the meson there is an invagination, the prephragma, which, how- ever, is usually not well developed in the nymph. The second portion of the mesoscutum lies between the cephalic pair of wing-cases. This represents combined scutum, scutellum, and postscutellum. It is nar- rowed cephalad, has a slight projection on each cephalo-lateral angle, the anterior wing-processes (Fig. 21, awp), and a similar, longer, one on each caudo-lateral angle, the posterior wing-processes (Fig. 21, pwp). Near the cephalic margin on the meson is an invagination indi- cating the location of the mesophragma. Immediately caudad of the mesoscutum and between the second pair of wing-cases is the metascutum. ‘This is similar in shape to the caudal sclerite of the mesoscutum, though somewhat larger, and possesses similar wing- processes on its lateral angles. There is no subdivision of the metascutum, but there is a deep invagination on the meson near the cephalic margin—the metaphragma. Mesothoracic Spiracles—These are located just laterad of the prescutum and are always hidden to a greater or less extent by the overlapping pronotum. Large tracheae are connected with them and the spiracles are doubtless functional during nymphal life. ‘The meso- stigmal plates are wanting in the nymph, and their derivation will be discussed later, in the description of the adult. Mesopleura.—These sclerites, occupying somewhat more than the cephalic half of the lateral aspects of the pleura, are approximate on their dorsal margin between the prescutum and the wing-cases. ‘The dorsal border extends from the mesostigma caudad to the second pair of wing-cases. The cephalic margin follows the caudal margin of the pronotum and extends ventrad from the mesostigma to the mesocoxae. The ventral border follows the contour of the coxal cavity; and the caudal border, forming a suture which may be known as the inter- pleural suture (Fig. 25, insu), extends from between the mesocoxae and metacoxae dorso-caudad to near the base of the second pair of wings. The mesopleura are each divided by three furrows into three 420 areas, two of which, the cephalo-dorsal and cephalo-ventral (Fig. 25, seps, ieps), comprise the episterna, and the caudo-ventral, the epimera (Fig. 25,epm). The ventral areas of the episterna (ieps) are known to odonatologists as the infraepisterna, and the dorsal ones incorrectly as the episterna. For convenience in designating the parts the latter may be known as the supraepisterna (seps). Mesosternum.—The mesosternum, that area between the meso- coxae, the caudal margins of the prosternum, and the cephalic margins of the metasternum, is not divided into separate areas, but the furcae are present and the deep furcal invaginations are very distinct (Fig. 24, fi). Metapleura.—The boundaries of each metapleuron are the inter- pleural suture, the metacoxae, the metathoracic wing-cases, and the pleura and sternum of the first abdominal segment. ‘The sclerites are each divided into three parts, the cephalic two comprising the metepisternum (supraepisternum and infraepisternum), and the caudal one, the metepimeron. ‘The metathoracic spiracles are located on these pieces near the union of the dorsal border of the metinfraepisternum with the interpleural suture. Metasternum.—The metasternum (Fig. 24, mtst) is similar in shape to the mesosternum, but is divided by sutures into three areas. The invaginations of the metafurcae are also prominent and a suture extends caudo-mesad from each. The two sutures tinite on the meson, extend caudad for a short distance, separate again, and extend laterad and caudad of the coxae. The areas on each side of the mesal line are the two halves of the sternellum (mtsm). Caudad of the sternellum is a broad sclerite possibly representing the first abdominal segment. This may be known as the intersternum (Fig. 24, ints). ‘There is no corresponding sclerite on the dorsum caudad of the thorax, but it may be that the latter portion has been lost. If, however, the intersternum be considered as a vestige of an abdominal segment, it will be found by actual count that there are twelve segments represented in the abdo- men of the nymph, a fact which makes one skeptical of the above inter- pretation. In some species, the area is membranous, and it is possible that the sclerite is nothing more than accessory membrane which has subsequently become chitinized. Trochantins.—The trochantins are wanting in the Zygoptera, and the mesal part of the coxae articulates directly with the sterna. Legs.—The legs are usually slender and not well adapted for cap- turing prey, the labium being wholly relied upon for that purpose. The coxae are nearly spherical and slightly compressed. The trochan- ter consists of two segments. The proximal segment is narrow and 421 capable of being telescoped into the coxa. The second segment is longer, and its ventral length is greater than its dorsal. The femora are subequal in length, the posterior being slightly longer, especially in Argia and the Lestinae. The tibiae are also nearly equal in length and are slender and cylindrical. The tarsi have three segments. The proximal segment is short and is extended below the second segment so that its ventral length is greater than its dorsal. The second segment is usually about twice the length of the proximal but, like the proximal one, is extended on the ventral side. The third segment is longer than either of the two proximal ones, being in some cases nearly twice as long as the second and four times as long as the first. At the distal end of the third segment, on the ventral surface, there can be found a small sclerite which probably represents an extra tarsal seg- ment and is known as the pretarsus (Fig. 19, pta). It is drawn out distally into a slender process. ‘The tarsal claws vary to some extent in length but are always sharply pointed and somewhat swollen at base. They are never bifid at the tip as in the adult. The legs of the nymphs never bear the long spines characteristic of the adult but, instead, there are weak setae or short spinules which collect particles of dirt and enable the insect to hide with ease. In the Agrioninae, there are to be found short, minute, three-pointed scales at the ends of the tibiae, the function of which is obscure (Fig. 19). The tarsi in all species possess two to four rows of short setae on the ventral surface. The markings of the legs vary with the genus, but consist largely of black rings on the femora and tibiae. In Agrion, nearly the whole of the femur is dark except a whitish ring near the apex. The tibial bands are mostly restricted to the proximal third and are lacking in most species. Wing-cases.—The wing-cases of Zygoptera appear early and at the completion of nymphal life usually extend as far caudad as the fifth or sixth abdominal segment (Fig. 25, wc). The tracheation of the pad is often obscure but the veins are sometimes plain enough to be of value in identification. Ontogenetic studies of the wings can only be made at intervals during the growth of the nymph, the obscure nature of the contents of the pad making such study difficult during the greater part of the time. In no case do we find the radial sector actu- ally crossing over the media as in the Anisoptera, and, as pointed out by Needham (’03), the subnodal cross-vein formed by the proximal end of the radial sector has been reduced and lost. The distal portion, however, may be seen in Lestes, but not usually in other species, and branches from the second media a short distance from its separation from the first media (Fig. 14, Rs). 422 Abdomen.—The abdomen is always composed of ten complete body-rings. The eleventh segment, seen best in Lestes, is represented by the small basal processes (Figs. 5, 18; A,,) to which the caudal gills are attached. The twelfth segment, supposed to be present in the minute sclerites bounding the anus, is apparently wanting or indis- tinct. Each body-ring is without sutures but is roughly divided by the lateral carinae into sternal and tergal areas. In the Coenagrionidae, the lateral carinae of the first eight segments are known as lateral. keels (Fig. 25, lk). In Lestes, the caudal extremity of each keel is sometimes drawn out into short setae and is setose or hairy along the | margins. Marginal setae are also present in the Coenagrionidae but the heavy caudal setae are wanting. Sexual Appendages.—It is claimed that the sexual appendages of the nymphs (Balfour-Browne, ’09) can not be seen and differentiated until about the time of the seventh molt. From personal observations, however, it would seem that the appendages appear much earlier than this, and possibly as early as the fourth molt. The male genital ap- pendages are located on the ninth abdominal sternum and consist of a simple pair of short, sharp, conical styli, near the ventro-meson. There is also an indication of the location of the male copulatory organs on the ventral surface of the second and third sterna (Fig. 24, ag), though nothing definite is formed there until the adult emerges. The ovipositor of the female is composed of six processes developing from the eighth and ninth sterna (Figs. 5, 18; oce, oca). Four of these are similar in appearance, being slender, curved, blunt projections extending commonly beyond the end of the ninth segment and frequently beyond the apex of the tenth. Laterad of this double pair of inner valves, can be found a pair of lateral styli which differ from the inner valves in being pointed at the tip and much broader at the base. The origin of the four median valves is partly from the eighth abdominal segment and partly from the ninth, the external ventral pair (oce) being derived from the eighth. Caudal Gills.—The caudal tracheal gills are present in the earliest stages and are reported to have been seen in the embryo. They vary from linear to broadly obovate in outline and from triangular to linear in cross-section. Cuticular pigmentation, if any, is either in transverse bands or is diffused over the entire gill. In many cases the tracheae contain pigment, which causes them to stand out in marked contrast to the rest of the gill. Along the margin of the gills are rows of spines or setae, which differ in number and extent in dif- ferent species. The lateral median ridges of the flat type of gills also possess rows of setae, but they are difficult to observe and are of little 423 importance in classification. ‘Two or more main tracheal trunks enter each gill and send off branches towards the margins. The mode of branching of the trachea is characteristic of many species, as is also the degree of pigmentation. A closed tracheal system has been considered possible and even probable in the Zygoptera, but thus far no connection has been traced by me, with the highest magnification obtainable, between the ends of the branches of the tracheae. The normal function of the gills is one of respiration, the minute tracheae being supposedly able to take up the oxygen from the water and to supply the animal with a sufficient quan- tity of the gas. Observations show, however, that complete loss of gills does not injure the insect to any appreciable extent; and it has been suggested that they also have cuticular and possibly rectal respira- tion, the latter thought to have been demonstrated in the Agrionidae. In young nymphs there is a pulsating movement in the region of the rectum, but cross-sections of the abdomen of Jschnura verticalis and several species of Enallagma show that there is no connection of the tracheal system with the alimentary tract other than a few small branches. What seems to be a more serious impairment of life activ- ities in the loss of the gills is the decreased power of locomotion which the insect suffers, the gills having the same importance as the tail of a fish. Loss of gills frequently occurs, in which case new ones are pro- duced ; but these appear only after the insect has molted, always remain small, and are usually abnormal in figuration and tracheation (Fig. 77a). For different types of gills see Figures 48-72, 75-77, and 8o. Cerci.—Anal appendages corresponding to cerci are present dorso- laterad of each lateral gill and vary in shape from tubercular to sty- liform (Figs. 5, 18; ci). ADULT The adults of Odonata are distinguishable from all other orders of insects by the type of their wing venation. The wing is character- ized by the presence of a nodus and a stigma and a large number of secondary cross-veins. ‘The presence of accessory genitalia on the second abdominal segment of the male is another unique feature. The Zygoptera are for the most part separated from the suborder Anisop- tera by the habit of folding their wings vertically when at rest. The abdomen is much more slender than that of the Anisoptera, and the wings are different in being contracted or petiolate at the base. Head.—In general appearance the head is wide and the eyes are very prominent, and as the head moves on a point of the microthorax its angle of rotation is very great. The epicranial furrow is present 424 on the dorsum near the caudal margin, similar in position to that of the nymph, and is, as a rule, indistinct unless the head is specially pre- pared in caustic potash. The furrow begins near the caudal margin of the dorsum, extends cephalad a short distance, forks, and extends latero-cephalad, caudad of the ocelli, to the margins of the compound eyes (Fig. 32, epcs). It can not be traced to the occipital foramen, but the homology of the furrow as a whole can not be doubted. There are three ocelli (0) cephalad of the Y, which are sometimes elevated _ above the surface of the head forming the so-called ocellar area. A furrow extends cephalad from the angle of the Y between the lateral ocelli and forks just caudad of the median ocellus. This furrow is | present in many orders of insects, but its true homology is not known. The front includes that portion of the dorsal aspect cephalad of the epicranial Y, between the compound eyes and cephalo-ventrad to the fronto-clypeal suture (Fig. 32, f). Cephalad of the median ocellus there is always a short, deep, transverse furrow which, although pres- ent in most Odonata, must not be mistaken for a suture. ‘The fronto- clypeal suture does not reach the margins of the compound eyes on either side. There is always a polished area on each side of the clypeus, which is a portion of the gena (Fig. 32, gn). The clypeus (Fig. 32, cly) extends ventrad of the fronto-clypeal suture and is divided into two parts by a transverse median ridge. The dorsal part, often dark and heavily chitinized, is the postclypeus; the ventral one, more weakly chitinized and often wrinkled, is the anteclypeus. The clypeo- labral suture separates the clypeus from the sclerite ventrad of it, the labrum (Fig. 32, Ibr). This sclerite is only slightly bilobed in most species of Zygoptera, the ventral margin is directed caudad, and the lateral margins are convexly rounded. Laterad of the bases of the mandibles, which lie at either side of the clypeus and labrum, there are small semi-ovate sclerites, the trochantins of the mandibles (Fig. 32,tm). The fronto-genal sutures are indistinct, but are represented by furrows extending from the dorsal articulations of the mandibles to the antennal fossae and laterad to the compound eyes. That por- tion of the, head on the dorsum and caudad of the arms of the epi- cranial Y, is the vertex (Fig. 32, vx), but it is not separated by a dis- tinct suture from the occiput, which occupies the dorsal half or third of the caudal aspect (Fig. 30, oct). ‘The postgenae, which occupy the ventral half of this aspect are separated from the genae by the oblique ridge mentioned above. ‘There is another ridge starting from the ventral condyle of the mandibles (Fig. 30, ocr) but extending dorsad instead of latero-dorsad. ‘This ridge disappears near the middle of the head. 425 Ocelli.—The location of the ocelli has already been described. They are moderately large, elliptical, and grouped in a triangle (Fig. 32, 0). Compound Eyes.—The compound eyes (Figs. 30, 32; ce) are large and contain a large number of ommatidia. They are located mostly on the lateral aspects of the head, but sometimes extend well onto the dorsum. Antennae.—The antennae (Fig. 32, ant) are usually composed of four segments. The condyle of the scape is especially prominent. The two terminal segments are styliform and resemble a single seg- ment. The greatest variation in the different segments lies in the length of the first, which ranges from hardly more than half that of the second segment, to an equal or greater length than that. There is also a less noticeable variation in the length of the third segment. Labium.—The labium (Fig. 37) is the ventral movable appendage of the head. It is a broad flat piece and covers nearly one-fourth the entire ventral surface. The submentum (sm), the proximal sclerite, is attached to the head and neck and comprises that part of the labium dorsad of the hinge when the labium is at rest. Immediately cephalad of the hinge there is a small, almost linear, transverse area, the mentum (me). Beyond this there is a large subtriangular piece with a deep me- dian, distal cleft and a suture-like furrow extending to the proximal end. This piece is the median lobe (ml) and represents fused glossae and paraglossae. On each side of this median lobe there are heavy blade-like lobes, the labial palpi, which connect with the proximal part of the median lobe. The fixed proximal segment is the palpiger (pl), the large movable distal portion is the proximal segment of the palpus, and the short blunt movable appendage borne by the proximal segment is the distal segment (lp,, lp.). There is a long, sharp, fixed hook mesad of the distal segment of the palpus, which in most cases is longer than the distal segment of the palpus. Mazxillae—The maxillae are just above the labium, one on each side of the mouth-opening. When the labium is applied to the ventral surface of the head, the maxillae are hidden, except the cardines and the caudal half of the stipites. The cardo and cardella are bent at an angle to the stipes, but when removed from the head along with the rest of the maxilla they are seen as two small sclerites attached to the proximal end of the stipes, the cardo being triangular and attached to the stipes, and the mesal side of the triangle forming the suture be- tween cardo and cardella. The cardella (Fig. 28, cl) is a very irreg- ular sclerite which articulates with the head capsule. Attached to the distal border of the stipes, the quadrangular sclerite which forms the body of the maxilla, are two appendages, the lateral more slender two- 426 segmented appendage being the palpus, the broader one, the fused galea and lacinia. The palpus has a number of large setae scattered over the surface. ‘The galea-lacinia is more or less compressed, and the distal margin has about six irregularly placed hooks arranged in two rows. A marginal fringe of heavy setae extends proximad from the hooks. In Hetaerina, if the galea-lacinia be placed on edge, there will be seen a strong indentation between the two rows of hooks, an indication of the fused condition of the piece. A study of Plecoptera (Fig. 31) and Ephemerida (Morgan, ’13) offers convincing reasons ~ for the interpretation of this piece as galea and lacinia fused, as com- pared with a belief in the reduction of the galea, or in the fusion of - this with the palpus instead of the lacinia, or in the reduction of the palpus. All degrees of fusion, from complete separation (Fig. 31) to complete fusion and disappearance of the suture, may be had in series selected from these two orders. Mandibles (Fig. 30, md).—All of each mandible is hidden beneath the labrum and labium except the lateral surface. ‘The teeth are strong and heavily chitinized and the distal margins are divided into two pro- jections, the cephalic one bearing a number of teeth, the caudal one with a number of teeth and cutting edges arranged in the shape of a Z. Hypopharynx (Fig. 30, hp).—The visible portion of the hypo- pharynx appears as a semicircular part between the tips of the max- illae. It is much more heavily chitinized than that of the nymph, and usually has a number of long setae attached to each lateral surface. Propharynx.—The propharynx is closely applied to the interior of the labrum and clypeus and presents no features of interest. Microthorax (Figs. 27, 29, 36, 39).—The microthorax comprises the neck sclerites, and is much reduced in the Zygoptera. The dorsal and ventral sclerites (notum and sternum) and the episterna are want- ing. ‘The only portions remaining are the conspicuous lateral plates, the epimera (min). In many species the epimera are much widened on the caudal third, and this portion is almost completely divided by a deep cephalic indentation. ‘The indentation separates from the main part of the epimera a bell-shaped dorsal part which serves as a buffer for the head and is to some extent freely movable. ‘The ventral part is slightly larger than the dorsal buffer, but is thrown into. folds, and the cephalic part of the ventral piece is drawn out into a long tapering point. The tips of the epimera are fastened together by ligaments and the head rotates upon the apices of the two together, which rest against the body of the tentorium. Thorax.—The thorax comprises the three body-segments caudad of the microthorax. ‘The first conspicuous ring is the prothorax. The 427 mesothorax and metathorax together form the division caudad of the prothorax and are so closely united that they appear as one segment. Prothorax (Figs. 27, 29, 36, 39; 41, pn).—The lateral margins of the pronotum are usually indefinite because of the disappearance of the noto-pleural suture or because of excessive pigment. Lestes is prob- ably the best form in which to study the prothorax on account of the clearly marked sutures between the sclerites. The caudal margin of the prothoracic dorsum extends caudad as a thin blade-like projection. There is a suture or furrow which extends cephalad from the lateral limit of the blade-like projection and marks the lateral extent of the pronotum (pn). Shortly cephalad of the caudal margin of the pro- notum and parallel to it there is a deep furrow which resembles a suture and extends from one lateral margin to the other. The area between this fold and the caudal margin is the caudal lobe of the pronotum. Cephalad of the lateral extremities of the caudal lobe, the suture mark- ing the lateral boundary of the pronotum arches dorsad a little and reaches the cephalic margin of the prothorax at the base of the mi- croepimeron. At this point there is a second transverse fold in the pronotum which is, however, large and more irregular than the caudal one mentioned above. ‘The area between it and the cephalic margin is the cephalic lobe. Near the dorso-meson, the cephalic fold bends caudad and there is a deep invagination here, the prophragma. Be- tween the prophragma and the caudal lobe there is a furrow which separates the remaining portion of the notum, not included by the caudal and cephalic lobes, into two equal, mesal or median lobes (Figs. 36, 39; pme). ‘The principal variations in the prothorax lie in dif- ferences in the caudal lobe and in the sculpturing of the dorsal sur- faces of the mesal lobes. In Nehalennia the caudal lobe is deeply incised and in Chromagrion (Fig. 170) this lobe is not only incised, but there are also two flat points, projecting laterad, one on each mesal lobe. Many other modifications also occur, most of which are sec- ondary sexual characters. Propleura (Figs. 36, 39).—The propleura, those areas ventrad of the pronotum and dorsad of the coxae, are each subdivided into three areas. Extending dorsad from the lateral procoxal articulation (pexp) there is a distinct suture which becomes indistinct before reach- ing the lateral margin af the pronotum. ‘This suture (pps), the pro- pleural suture, is usually depressed and the depression is continuous with that forming the cephalic fold of the pronotum. Caudad of the propleural suture there is a large, rounded area which forms the caudo- lateral angles of the prothorax, and ventrad of this is a small, falcate area. Both areas constitute the proepimeron (pepn), there being no 428 real suture between the two. Cephalad of the propleural suture is a somewhat triangular area, the proepisternum (peps), the cephalo- ventral angles of which are drawn out and extend ventrad in front of the procoxae. ‘The cephalo-ventral arms of the proepisterna are fused with the propreepisterna. Between the dorsal triangular portion of the preepisterna and the microepimera is a small, much-wrinkled area, which appears to be composed of a number of sclerites. This, how- ever, belongs to the proepisternum. Prosternum (Figs. 27, 29).—The cephalo-ventral arms of the episterna, as described above, extend ventro-cephalad and become ap- proximate but not quite contiguous on the ventro-meson. Caudad of © the approximated ends of the episterna there is a large shield-shaped ventral sclerite the caudal margin of which is concave. This is the fused sternum and presternum (prst). The caudo-lateral angles are usually acute, and at the tips of these angles are found the deep in- vaginations of the furcae (fi). Caudad of the sternum and between the furcae is a-heavily pigmented chitinized area, the sternellum, which extends about as far caudad as the caudal margins of the coxae. In some cases there is within the sternellum an elliptical or oval depressed area much resembling a true sclerite. This is a secondary formation. On each side of the meson, caudad of the sternellum, is a heavily chi- tinized bar which extends latero-caudad and is attached to the meso- thorax. These bars represent the furcella (fl). Mesothorax and Metathorax (Figs. 40-47 ).—This division of the thorax bears the two pairs of wings and the second and third pairs of legs. A glance at the mesothorax and metathorax of any dragon- fly will show that the wings, instead of being borne on the mid-dorsum of the thorax, are situated far to the rear and are inserted just above the cephalic margin of the first abdominal segment. This change in wing position has brought changes in the structure of the thorax as a whole, including the reduction of primary sutures and the appear- ance of many secondary ones, and as a result the external thoracic skeleton of Odonata is as complex as that of the highly specialized Hymenoptera and Diptera. Mesnotum (Figs. 41, 44, 46, 47).—As has been mentioned in the nymphal description, the mesepisterna are approximate on the dorso-meson. In the adult the two have united and fused, a single suture being left, extending from near the caudal margin of the pro- notum to the wing bases. In some cases this suture is slightly elevated, forming a carina (dc), but it is often flattened at the point of fusion of the two pieces and the suture nearly obliterated. Cephalad of the dorsal carina there is a small somewhat rhomboidal area, the prescutum 429 (mscl). There is a deep invagination near its cephalic angle but no invaginations of the internal skeleton occur here. Caudad of the caudal extremity of the dorsal carina and adjacent to the wing bases there are two small, frequently subcrescentic pieces which are approxi- mate on the mesal margins and extend well towards the first lateral suture of the thorax. These are the combined mesepisternal paraptera (p). Caudad of the mesepisternal paraptera, but on a distinctly lower level and between the first pair of wings, is the second portion of the mesonotum, which consists of a number of irregular hummocks sep- arated by depressions, sutures, and ridges. Just caudad of the parap- tera on the dorso-meson there is a very deep invagination of the mesa- phragma, which is situated near the cephalic margin of the mesoscutum (msec). At this point the mesoscutum is narrow, but widens soon after extending caudad a short distance and forms a process, the anterior wing-process. From this point the margin extends caudad and forms a similar process, the posterior wing-process. ‘The caudal boundary of the scutum is formed by a heavy chitinous line, bent caudad and extending from side to side between the caudal wing- processes. _From the caudal wing-processes the lateral margins of the mesonotum, now the scutellum, extend caudad to the point of entrance of the spring-vein (Figs. 46, 47; spn) which always marks the caudal margin of this sclerite. ‘The central portion of the scutellum is ele- vated to form a sort of knob, which is heavily chitinized. The portions on either side of this are depressed and as a rule less heavily chitinized than the elevated portion. The area caudad of the spring-vein is the postscutellum (mopl), the latter extending as far as the deep fold which forms the cephalic border of the metaprescutum. - Metanotum (Figs. 46, 47).—The metaprescutum (psct) is a nar- row, transverse, heavily chitinized sclerite forming the cephalic mar- gin of the metanotum. It is in great part covered by the membranous postscutellum of the mesonotum but can usually be seen through the latter. On the lateral angles, there are slight ental projections. Caudad of the transverse prescutum, there are four large areas composing the scutum (mtsc) and three deep longitudinal folds which mark off the four areas, but no primary sutures. There is also a somewhat irregular area caudad of the four larger ones. The caudal margin of the scutum is depressed laterad, and the latero-caudal angles project and form the anterior wing-processes. The metascutellum (masl) is similar to the mesoscutellum (mosl), the caudal boundary being marked by a spring-vein (spn) and the sclerite, as in the former case, having a raised central portion and depressed lateral ones. The postscu- 430 tellum comprises the area caudad of the spring-vein and cephalad of the first abdominal segment. Mesothoracic Spiracles and Mesostigmal Plates (Figs. 41, 43-45, 212-216).—The mesothoracic spiracles of Zygoptera are large and have exceedingly large tracheal trunks connected with them. As in the nymph, the spiracles have migrated dorsad and are located near the lateral angles of the mesoprescutum and beneath the projecting caudal margins of the pronotum. Adjacent to the spiracle on two. sides, are two heavy plates, the ventral one of which is highly polished (Fig. 45, mstv), allowing the prothorax to play upon it to a certain - extent. The caudal plates (mstg) are usually triangular and assume a variety of forms in different species. Both of these plates belong to the peritreme of the spiracle. The caudal plate has been assumed by Snodgrass (’09) to be homologous with the depressed area in Anisoptera which extends across the dorsum just caudad of the pro- notum.. A study of the nymphs of Anisoptera proves conclusively that such is not the case, for in the nymph the depressed area may be cbserved to develop from the mesepisternum. Another possibility in the derivation of the caudal plates is that they have arisen from the mesoprescutum, and the wide depressed area of Anisoptera may also have had the same origin. This is strongly supported by the apparent disappearance of all traces of the prescutum in the adults. There is, however, a remnant of the prescutum in the adults of Gomphus where the area occupied by the prescutum lies entirely within the transverse depression and the true stigmal plate is closely applied to the stigma. From this it seems that the depressed area of Anisoptera can not be homologous with the spiracular plates of the Zygoptera, but.that it must have developed simply from a depression of the mesepisterna. Use has been made of the caudal stigmal plates in the classification, especially in the case of the females, of the genus Argia. Kennedy (’o2a) and Calvert (Calvert and Hagen, ’02:103) were the first to call attention to these plates in America, but their use was hinted at as long ago as 1865 by de Selys (65: 381). In the genus Argia the caudo- mesal angles are the variable parts of the sclerites. There is considerable difference also in the plates of females of the Coenagrionidae, and individuals of this sex may often be separated by the use of this character. In the Lestinae and Agrionidae, the character seems to be without value, which fact makes the members of the genus Lestes, at least, one of the most difficult of all genera of Zygoptera to determine. Mesopleura (Figs. 43, 45).—The mesopleura are closely united to the metapleura in most Zygoptera and the interpleural suture has been lost in many cases. This suture can be traced for its full length 431 only in the family Agrionidae (Fig. 45, insu), in which it extends from a point between the mesocoxae and metacoxae, caudo-dorsad to the caudal margin of the first pair of wings. Mesepisterna (Figs. 43, 45).—The mesopleural suture, dividing the mesopleura into episterna and epimera, may be traced by locating the lateral articulation of the mesocoxae (Fig. 40, mcp) and the mesopleural wing-process (wp)—a heavily chitinized process extend- ing from the caudo-dorsal margin of the thorax into the membrane at the base of the first pair of wings. The suture will be found to ex- tend cephalad, beginning at the wing-process, parallel to the dorsal carina, as far as the cephalic third of the mesothorax, where it appar- ently forks, and sends one branch cephalad and the other ventrad to the coxal process (mep). The horizontal fork is a secondary suture and separates the small sclerite above the coxae, the infraepisternum (seps), from the rather large oblong sclerite, the supraepisternum (seps). Mescpimera (Figs. 43, 45).—The mesepimera lie caudo-ventrad of the mesopleural sutures. In the Coenagrionidae they are fused with the metepisterna and the interpleural suture is obsolete except near the wing bases. In the Agrionidae the interpleural suture is dis- tinct throughout its course, and the metepimera are then elongate sclerites with the dorso-cephalic angles considerably rounded. Mctapleura.—The key to the metapleura is the metapleural suture, which may be traced in a similar manner to the mesopleural suture. This may be done by finding the metacoxal articulation and the meta- pleural wing-process (wp), situated at the base of the second pair of wings, and following the suture between the two points. Metepisterna (Figs. 43, 45).—The metepisterna are those portions of the metapleura cephalad and dorsad of the metapleural suture (Fig. 45, mtsu). Like the mesepisterna they are divided into two separate sclerites, a small one dorsad of and adjacent to the coxae, the metin- fraepisternum, and a larger, elongate one dorsad of the metinfraepi- sternum and extending from the cephalic margin of the latter caudo- dorsad to the bases of the wings—the metasupraepisternum (seps). The latter is narrowed to about half its width above the infraepisternum and usually bears the metathoracic spiracles (Fig. 43, mtsl) within the constricted portion. In many species there is a secondary suture extending between the spiracle and the metapleural suture (Fig. 45). Metepimera (Figs. 43, 45).—Caudo-ventrad of the metapleural suture is the metepimeron. The metepimera are contiguous on the ventro-meson. In the Agrionidae the boundaries of the sclerite, be- ginning with the metacoxal process (mtcp), may be indicated as fol- 432 lows :-—The margin extends ventro-mesad (Fig. 40), meeting its fel- low from the opposite side on the meson, then extends caudad half- way from the coxae to the first abdominal segment, bends laterad to the elevated lateral carina, caudad again to the abdomen, then dorsad (Fig. 45) along the wing bases to the metapleural suture (mtsu), which forms the dorso-cephalic border of the sclerite. At the caudo- ventral angles of the epimera there is a small triangular sclerite which is apparently cut off from the main portion of the epimeron. The_ primary suture follows the ventral margin of the deep fold which occurs at this point. ‘The latero-ventral carina does not follow the ventral suture of the epimera all the way from the abdomen to the coxae, but, instead, follows a more direct line along the ventro-lateral margins of the thorax and diverges from the suture half-way from the abdomen to the coxae (Fig. 40). In the Coenagrionidae the sutures marking the ventral borders of the epimera are less distinct and do not follow quite the same course (Fig. 42). Mesosternum and Metasternum.—The approximation of the coxae in the adults of Zygoptera has brought about profound changes in the mesosterna and metasterna. Mesosternum (Figs. 40, 42; mst).—The key to the mesosternum lies in the ee of the furca (mfi) which mark the caudal limits of the sternum. ~ In the Agrionidae the elevated parts of the sternum and sternellum form a distinct hour-glass figure with the furca on either side of the contracted portion. The margins of the sclerites are, however, parallel to the elevated portions, but are somewhat de- pressed. If the cephalo-lateral angles of the sternum are followed to the sides of the thorax they will be found to extend neagly as far dorsad as the dorsal margins of the mesinfraepisterna. The cephalo- lateral arms are expanded dorsad, and there are apparently several sclerites represented in the upper portions, possibly the remnants of the mesopresternum (Figs. 43, 45; pst). Along the lateral margins of the sternum cephalad of the furcae there are obscure invaginations which represent the prefurcae (mpf). These are difficult to see from the exterior unless the cuticle is cleared. Mesosternellum (Figs. 40, 42; mstm).—The mesosternellum is similar in shape to the sternum except that the caudal margin is convex and heavily chitinized in some groups, notably the Agrionidae. The chitinized portions represent furcellae. From the caudal margin of the mesosternellum there extends a short, heavy, chitinous projection which sinks into the metathorax, and is lost from sight beneath the metasternella. This isa part of the metasternum (Figs. 40, 42). 433 Metasternum (Figs. 40, 42).—This sclerite is even more pro- foundly modified and distorted than the mesosternum. The meta- coxae are almost contiguous and the muscles attached to the meta- sternum along the meson have drawn it well into the interior. The metafurcae can only be seen upon dissection of the thorax, and are to be found closely approximated along the ventro-meson. The pre- furcae (mtpf) are a short distance cephalad of the furcae (mtfi). ‘The presternum and sternum are fused, and the cephalo-lateral arms extend around the cephalic margins of the coxae and unite with the metinfraepisterna. The sternellum is represented in each sclerite miesad of the caudal half of the metacoxae, the caudal boundary being marked by two nearly contiguous chitinized spots on the meson (Figs. 40, 42). Intersternum (Figs. 40, 42; ints).—The closing together of the metepimera has apparently resulted in the isolation of a portion of the sternum, near the abdomen. Comparisons with the thorax of Orthoptera and other orders show that this may be a portion of the abdomen, but in this case it is probably the cuticular membrane de- veloped between the abdomen and-thorax. The possibility that this sclerite represents an extra abdominal segment has already been dis- cussed under the description of the nymphal thorax. The name inter- sternum has been applied to this area. Postcoxal Area.—The area on the thoracic venter between the lateral carinae, caudad of the metacoxae and cephalad of the first ab- dominal sternum, is the postcoxal area. Legs.—The legs are long and comparatively slender, and have long setae arranged regularly in rows (Fig. 35). They are not adapted for walking or running. Coxae (Fig. 35, cx).—The coxae are large and globular, and there are prominent ridges on the lateral surfaces of the procoxae and the caudo-lateral surfaces of the mesocoxae and metacoxae. Trochanters (Fig. 35, tr).—The trochanters are much smaller than the coxae and are divided into two short pieces in all families. The ventral length of both portions is much greater than the dorsal. Femora (Fig. 35, fe).—The femora are long and cylindrical and without carinae except in a few genera. The ventral surface is pro- vided with two rows of long black setae (fs), varying in number from three or four on the fore tibiae to as many as sixteen or seventeen on the hind tibiae. Tibiae (Fig. 35, ti) —The tibiae are likewise long and slender and have a double row of setae on the ventral surface. In the fore tibiae of most species the setae of the cephalo-ventral row are conspicuously 434 flattened. ‘The comb (tic) formed by these closely placed setae is probably used for cleansing the mouth-parts or the antennae. There is a great deal of variation in the length of the tibial setae and also in the number present in different subfamilies. Tarsi.—The tarsi are always composed of three segments, the seg- ments increasing in length from the proximal to the distal end (Fig. 35, ta). They are also provided with a double row of setae beneath, but these are never as long as the tibial or femoral setae. Pretarsus.—The pretarsus (Fig. 19, pta) is beyond the end of edie third tarsal segment and consists of a small shield-shaped piece on the ventral surface just beneath the bases of the claws. It extends back into the third segment, and in order to be seen best the claws should be pulled outward a little. There is also a small projection attached to the tip of this sclerite, but this is not homologous with the empodium of other insects. ‘The ventral apical margin of the last segment of the tarsus is deeply emarginate on each side of the pretarsus. Claws.—The claws are long and slender and the tips are always notched or bifid (Fig. 35, cw). The rays are seldom equal in length, and in some species the notch is far proximad of the apex. Wings (Figs. 73) 74, 78, 81-90).—All Zygoptera have four sim- ilar membranous wings. in respect to venation and shape, the genus Hetaerina may be said to have the most primitive wing of any zygop- teron found in Illinois (Figs. 74, 78). The position and course of the veins in the wings of this genus are as follows: —The costa, first longitudinal vein, forms the cephalic margin of the wing. The sub- costa, second longitudinal vein, extends half the length of the wing from the base and ends abruptly in a short fork which marks an in- dentation in the margin. The two forks of the tip of this vein are in line with a heavy cross-vein caudad of it, and the brace formed by the alignment of the cross-vein and the subcostal forks is known as the nodus. ‘The third longitudinal vein extends from base to apex of the wing and is composed of fused radius (R) and media (M) as far distad as the nodus and first radius (R,) plus the second subcosta from nodus to apex. ‘There are a number of cross-veins extending between costa and subcosta from the base of the wing to the nodus— the antenodal cross-veins. Between costa and radius, distad of the nodus and proximad of the stigma—the heavily chitinized spot near the apex of the wing—are the postnodal cross-veins. The remaining branches of the radius are united, forming the radial sector (Rs), and separate from the main trunk at the nodus. The course of the radial sector is difficult to follow because of its crossing one or two of the median veins. In Hetaerina the radial sector branches from the radius 435 at the nodus, crosses the first median vein, the first vein caudad of it, at the point where the second median vein separates from the first, fol- lows the second vein for a short but indefinite distance, being fused with it, and then crosses over to the longitudinal vein caudad of the second media, and continues its course to the margin of the wing (Fig. 74). The point of separation of the radial sector from the second media is not evident, there being no oblique cross-vein as in the Ani- septera. The vein uniting the caudal end of the cross-vein over which the radial sector crosses, to the main radio-medial trunk is known as the bridge (seen in Lestes and Ischnura, Figs. 81, 85; br), and is secondary in origin. In Hetaerina the trachea of the bridge is fully as strongly developed in the nymph as any other of the main tracheal trunks. Such a feature would perhaps throw some doubt on the actual formation of the bridge in this suborder were it not for the strong comparative evidence present in the Anisoptera. The bridge reaches R-plus-M about half-way between the nodus and the base of the wing. About one-third of the distance from the base to the nodus is a strong, oblique cross-vein, the arculus (Figs. 81, 85; arc), from the middle of which two longitudinal veins arise. These veins are the third and fourth median veins (M, and M,), respectively, the cephalic one being M,. A short distance from the arculus there is another heavy cross- vein connecting M, with the longitudinal vein caudad of it. The cross- vein probably represents the medio-cubital cross-vein. The four-sided area enclosed by this vein, the portions of M, and the longitudinal vein caudad of it (the cubitus) and distad of the arculus, forms what is known as the quadrangle (qd), and corresponds to the cell first My. The cubitus extends from the base of the wing to the distal side of the quadrangle, where it forks and sends out two longitudinal branches caudo-laterad to the margin of the wing. The forks are Cu, and Cup, or first and second cubitus. The anal vein (A) consists of a single heavy trunk extending from the base of the wing and apparently con- necting with the cubitus at the point where the latter forks. The dif- ferent anal veins can not be traced because of numerous secondary cross-veins. Many variations occur in the above wing-venation, but instead of a discussion of each in detail the reader is referred to figures 73 and 81-90 which show the types of venation occurring in the remaining genera of Zygoptera found in Illinois. Abdomen (Figs. 91-100, 104.).—The abdomen of all Zygoptera is cylindrical and composed of ten complete segments. In all of the seg- ments the sterna are much reduced and hidden by the overlapping terga. The pleura are still more reduced, so that no portion of them 436 can be seen in the normal insect. If the body be softened and the lateral margin of the terga extended, the pleura appear as membrane between the margins of the terga and the sterna. In this membrane, near the cephalic-lateral margin of the first eight segments, the ab- dominal spiracles are found. The terga of all the segments are always large, are bent around from the dorsum onto the lateral aspect of the abdomen, and usually extend slightly onto the venter. A _ single tergum, then, has a dorsum and pleuron of its own. ‘The terga are- usually transversely rugose on the dorsum, and the lateral margins are always paler than the dorsum, and finely pilose. The apical margins of . all except the last segment have elevated subapical chitinous rings which are frequently provided, especially in the terminal segments, with a number of short, heavy setae. The apical margin of the tenth segment may bear a long spine at the apex (Fig. 110), or the apical margin may have a long, subapical, blunt process (Figs. 166, 167), or it may be simply emarginate. ‘The sterna are narrow transversely, with the exception of the first two and the last two, and are more or less hidden by the margins of the terga. ‘The first sternum (Figs. 40, 42) is usually subtrapezoidal with the cephalic margin concave. The second sternum of the male is developed into an accessory copulatory appara- tus which will be described later. In the female this sternum is sim- ilar to sterna three to eight and consists of an oblong plate of chitin, slightly wider cephalad, and having small ental projections at the ceph- alo-lateral angles. The eighth sternum of the female is divided into three sclerites (Figs. 109, 116), a single large proximal one and two small, sometimes obsolete, ones which are intimately connected with the first pair of gonapophyses. The ninth sternum (Figs. 109, 116) is greatly reduced in the female, being represented by narrow sclerites along the margins of the tergum extending from the proximal end to about the distal third or half of the segment. ‘The ninth sternum of the male bears the genital opening, and on each side of this, and cov- ering it, there is a more or less oval plate. These plates are known as the parameres (pa, Figs. 118, 121, 147, 165, 171, 172, 183). The tenth sternum is fused with the tergum on the lateral aspect. Abdominal Appendages.—This term includes the accessory gen- italia and anal appendages of the male, and the ovipositor of the female. Accessory Genitalia (Figs. 33, 97, 98, 101, 105, 107, 108, 120, 122),—The accessory genitalia of the male are derived from the sec- ond and third sterna, and a portion sometimes from the second tergum. The sperm duct opens in the ninth sternum and spermatozoa are trans- ferred to the accessory pouch or vesicle by doubling the abdomen upon 437 itself. ‘The sternum of the second segment forms two heavily chi- tinized hamules (Fig. 33, hm) which serve as covering plates. The membranes immediately below these form a sheath for the penis (Fig. 33, ps). The latter is very heavily chitinized and is bent entad, extend- ing to about the middle of the abdomen, and at the ental end are at- tached heavy muscles which operate the organ. The tip of the penis is largely membranous and flexible, and exhibits modifications which appear to be of specific value in classification, at least in some genera. The tip fits behind a heavy cephalic projection of the third sternum, the seminal vesicle, when not in use (Fig. 33, sv). Small knob-like projections may be seen extending ventrad from the lateral margins of the second tergum and just caudad of the hamules. These are fre- quently concealed in the Zygoptera but are large and conspicuous in the Anisoptera where they are known as the genital lobes (Fig. 33, gb). The cephalic third or less of the third sternum is elevated, heavily chitinized except at the tip, and extends some distance cephalad of the cephalic margin of the segment. In a few Anisoptera this part is re- ported as functioning as the penis, the parts already described for Zygoptera being unimportant. : The variations occurring in this organ throughout the suborder are marked and are in all cases of generic rank as diagnostic characters. In closely related specific groups, however, it can not be relied upon, and recourse must be had to the anal appendages. Anal Appendages (Figs. 34, 38, 109; aas, aai).—At the caudal extremity of the abdomen of the male there are always four appen- dages; an upper dorsal pair, the superiors (aas), and a lower, the in- feriors (aai). Of these, the upper is more often the longest, but it may be reduced and shorter than the ventral pair. The anus opens between and slightly dorsad of the bases of the mesal lobes of the ventral pair. The dorsal pair of appendages is frequently forcipate, and the tips are often contiguous and sometimes have between their bases a knob-like projection. Ovipositor (Figs. 109-116).—The ovipositor of the female con- sists of three pairs of valves or gonapophyses. The ventral, mesal pair are slender and heavily chitinized, and are transversely ridged at the tip and usually provided with a saw-tooth edge. The cephalic pair of gonapophyses (oce) is derived from the eighth segment ; the median pair (not shown in the figures) and the broad caudal pair (oca) from the ninth segment. The caudal pair of gonapophyses differ much in shape from the cephalic and median pairs. ‘They are very broad at the base, somewhat contracted at the apex, and bear short, chitinized, curved subapical rods, the prostyles (prs). The ventral margins of 438 the caudal valves are always serrate. Variations in the ovipositor of the female are seemingly of little importance in classification although there is enough difference in the apical sternites (stig) of the eighth segment alone to facilitate the sep- aration of genera. Liré History AND Hasits The metamorphosis of all Odonata is incomplete and the life his-_ tory relates to the egg, nymph, and adult. EGG The eggs of Zygoptera are elongate and ovcidal, their length being much greater than their transverse diameter. In length they average about one millimeter; in diameter usually about one-fourth of this. They are inserted either above or below the surface of the water in the stems of plants. Lestes and related genera insert the eggs con- siderably above the level of the water, and several instances are re- corded in which the plants suffer from excessive oviposition. Most of the Coenagrioninae oviposit beneath the water upon the submerged parts of plants. To accomplish this, the female with the male clinging to her alights on a projecting part of a plant and backs down into the water dragging the male with her. She often goes so far beneath the surface that both are completely submerged. Kellicott (’99: 24) observed the females of Argia moesta putrida descend into the water ir. this fashion; and I have frequently seen Enallagma signatum de- scend into the water to oviposit and, less frequently, /schnura verticalis and Enallagma antennatum. It is probable that many more of the subfamily Coenagrioninae enter the water to find a suitable place for oviposition. The egg-laying habits of the Agrionidae have not been extensively studied; but Kennedy (’15: 339) reports that Agrion aequabile variety yakima deposits the eggs beneath the surface of the water upon willow roots, and is unaccompanied by the male. Need- ham also says that Agrion maculatum oviposits just beneath the sur- face of the water, but Wesenberg-Lund (’13) observed a European species depositing eggs above the water. In all cases the female was unaccompanied by the male. The number of eggs laid by a single female has been but partially investigated, owing to the great difficulty of inducing the female to lay in captivity. A number of adults were dissected with a view to discov- ering the egg-laying capacities of the group. Several reared specimens which had no chance to deposit eggs were found to contain as many 439 as 1000 ova but only 60 or 70 of them were of normal size and con- sidered mature. Another female, /schnura verticalis, contained 203 mature ova, while a third teneral female of Enallagma hageni con- tained 290 mature ova. Calvert (’93) says that the average dragon- fly probably lays between two and three hundred eggs, and this state- ment seems to coincide with that above. The length of time spent in the egg stage is also imperfectly known. Lucas (’00: 18) reports that Sympetrum striolatum spends a month in this stage. Balfour-Browne (’09:256) says that eggs of Ischnura elegans and Enallagma pulchellum, laid at the beginning of August at East Norfolk, England, required from four to five weeks to develop. The temperature relations are not mentioned, but it is probable that this period varies to some extent. Needham (’03) calls attention to the fact that the eggs of Lestes, which are laid above water late in July, develop to a certain point, apparently ready to hatch, and await submergence before eclosion. ‘The water does not reach them until late in fall; and this means that at least several months are spent in the egg stage. Brandt (’69) reported the development of Agrion (Calopteryx) virgo in three weeks during a hot summer. In the final stages of embryonic development the head is directed towards the small end of the egg. This end is always nearest the cuticle of the plant, and the nymph consequently emerges head first. NYMPH Growth—Immediately after hatching, the nymph is helpless and unable to move about actively. In this condition it is known as the pronymph (Balfour-Browne, ’09:258). A few minutes afterward the skin of the pronymph splits and the true nymph escapes. During the second nymphal stage the nymph is a minute insect, hardly longer than the egg from which it hatched. The antennal segments are three and there are no wings or sexual appendages. From this stage the nymph grows and molts at intervals, the time between molts depending largely upon the temperature and the amount of food which it is able to capture. The antennae increase in number of segments until six are present, in which condition they remain until the last nymphal stage, when there are seven. The wings appear as ridges during the fourth stage, but the sexual appendages do not appear until the seventh stage, according to Balfour-Browne (’09). This seems to be contra- dicted by the rather frequent observance of nymphs without wing-cases and fairly well-developed appendages. ‘There is great variation in the time between molts, due primarily to temperature. It often happens 440 that when nymphs are brought into the warm laboratory they molt within a few days. Balfour-Browne found surprising differences in the time between molts in nymphs kept at constant temperatures, so that it would seem probable that other factors enter into the problem besides temperature. He was able, however, to reduce the length of the stages by raising the temperature, and found that in some cases these lasted, in low ‘temperatures, for 150 days, while in others they lasted only five days at higher temperatures. The number of molts varies from ten to fifteen in the Coenagrionidae, and the length of the” nymphal life may range from 229-624 days (Balfour-Browne, ’o9). Habitat.—In nature, the nymphs are most often found hiding ~ among the weeds and rubbish along the margins of lakes, ponds, and streams. A few have been taken under rocks in swift currents, among them Argia putrida (Needham, ’03) and Argia tibialis. The Agrionidae frequent the swifter currents, and seem to prefer these situations to any others. ‘They are never found in stagnant ponds. Nymphs of Lestes, on the other hand, do not occur except in stagnant woodland pools, and are never taken along the banks of streams unless a stagnant condition is present. ‘They prefer the shade, and hide among the broad-leaved types of small water-weeds, being rarely found among the narrow-leaved rushes and saw-grass. Riley (’12) says that the nymphs of Zygoptera react negatively to light from a pro- jection lantern but that such a reaction is often inhibited by the habit of clinging to objects. He was unable, however, to obtain similar reactions to moderately strong daylight. Reactions to heat have not been studied, but the nymphs are able to withstand temperatures near the freezing-point and may be collected during the winter from be- neath the ice. They readily succumb when the temperature of the water rises much above 70°F., but flourish well at 66.2°F. or 19°C. (Balfour-Browne, ’09). Lestes i is particularly sensitive to high tem- peratures, and when in captivity considerable care must be taken to keep the temperature low enough for them. Food.—The food of the nymphs consists almost entirely of Crus- tacea, the larvae of nematocerous Diptera, such as mosquitoes and chironomids, and ephemerids. Very young nymphs have been known to thrive on Paramecium and other Protozoa. Of a large number of Lestes which were dissected, nearly all contained Daphnia and Cyclops, while the coenagrionines dissected contained many heads of chirono- mids and only occasionally small Crustacea. However, a single small Ischnura verticalis nymph contained eight specimens of Daphnia, and it seems highly probable that other insects are also taken when the normal food supply is scarce. Diatoms and other minute organisms 441 are frequently found in the alimentary tract, but this is due to the fact that other insects have been eaten which feed upon these organisms. The following is a list of the kinds of food known to be eaten by zygopterous nymphs. aretazoa, . 0 3) a) 1.0% » Paramecium. Crustacea Copepodag e+) -ta 4 a Gyclops: Anemopoda. . . Daphnia. Arthropoda Arachnida; . . Hlydrachnidae (rare). Diptera—Chironomidae, Culicidae. Insecta . . . . 4 Odonata—Zygoptera. Ephemerida—Ephemeridae. Mentebrata tT). Shs 4. Very youti¢g fish. Color Adaptations.—In almost any collection of live zygopterous nymphs, there will be found brown and green individuals of the same species. When collected from localities with abundant green vegeta- tion, nearly all the nymphs will be green; when taken from situations where little green vegetation occurs, the nymphs are brown or dark in color. Furthermore, as has been observed in rearing specimens, green nymphs placed in a jar without green plants become brown after a few molts, and thus seem to be able to adapt themselves to the color of the surroundings. The color of the nymph, contrary to what might be expected, seems to have no influence upon the color of the adult. Enemies.—The nymphs of Zygoptera are preyed upon by a number of enemies, the most formidable of which are fishes. Forbes (’88) reported that odonate nymphs formed ten to thirteen per cent. of the food of Perca flavescens—the common perch, Aphredoderus sayanus —the pirate perch, and Pomo.is annularis, the crappie ;and twenty-five per cent. of the food of the grass pickerel, Esox vermiculatus. Riley * (12) says that Lepomis gibbosus, a common sunfish, and the yellow perch, Perca flavescens, commonly feed upon agrionid (coenagrionid) nymphs. Among the predaceous aquatic Hemiptera, the genera Ranatra, Belostoma, and Notonecta, and probably others, feed upon the nymphs. A mite, Arrhenurus sp., is a common external parasite of the nymph. At the time of emergence of the adult, the mite migrates from 442 the nymph to the adult and is carried about by the latter until it is nearly mature, when it escapes again into the water for the final stage. Another mite has been reported to feed upon the eggs of Anisoptera, but this statement has not been verified for the Zygoptera. Needham (’03) says that a large number of hymenopterous parasites prey on the eggs of Lestes, left exposed above the water-line, and he reared the following species: Brachista pallida Ashm., Centrobia odonatae Ashm., and Polynema needhami Ashm. Brandt (’69) also reports- rearing Polynema ovulorum from the eggs of Agrion (Calopteryx) and says that as many as fifty per cent. of the eggs were sometimes destroyed by this parasite. A fungus belonging to the Saprolegniales frequently attacks the nymphs, especially if enfeebled from any cause. Sometimes it be- comes very difficult to rear specimens, and if the rearing-jars become infected nothing short of thorough sterilization will be of any avail. This fungus is related to the one attacking fish and causing great damage in hatcheries. It is also known to attack the larvae of Coryd- alis. Emergence of Adult—-When the nymph has molted a stated number of times, somewhere between ten and fourteen, and has be- come full-grown, it crawls out of the water, dries its cuticle, which soon splits along the mid-dorsum of the thorax and head, and the adult emerges. The nymphs of Zygoptera usually seek the sunlight to transform and emerge early in the morning, the greater number being clear of the skin before eight o’clock. A much smaller num- ber have been seen to emerge after six o’clock in the evening or late in the afternoon, but very few, if any, emerge during the heat of the day. The emergence follows a more or less definite schedule. When first out of the nymphal skin, the parts of the body are no larger than the parts of the foregoing nymph, and the insect is yellowish green in color. Great changes soon begin, including an elongation of the abdomen and wings as well as enlargement of other parts, and within an hour the insect is ready to take flight. At this time it may show mature coloration or the color may still be incompletely developed, and in this condition the adult is known as teneral. The teneral state may last for several days or longer, depending somewhat upon the amount of sunlight to which the insect is subjected, or there may be no further change after the power of flight is attained. Enallagma exsulans, E. geminatum, and the male of Ischnura verticalis are ex- amples of species which apparently have no teneral state. Enallagma carunculatum, and Ischnura verticalis, female, are examples of spe- cies which apparently have a long teneral period. The change from 443 teneral to full adult coloration is a phenomenon which is not well understood. Just why the thoracic stripes of Enallagma signatum, for instance, should change from a pale but distinct blue to a bright orange in the course of development, while the stripes of the same region in Lestes rectangularis change from a dull brown to pale blue, is impossible to explain without a more thorough knowledge of the chemical nature of the pigments which undergo the changes. The following observations were made upon the emergence of Ischnura verticalis. ‘The rate of development is approximately simi- lar to that of all Coenagrionidae. ‘The rearing-jar was kept in the laboratory on the west side of the building and hence did not get the early morning sun. This accounts for the late emergence of the nymph. 9:30 A. M. The nymph crawled out upon the weeds within the jar and seemed about ready to emerge. The nymph when removed was dissatisfied and restless and tried to get a firm hold on something with its claws. 9:35. Body nearly dry. 9:45. The thorax suddenly splits and the insect rapidly emerges from the skin; color mostly light green and pale yellow; dorsal por- tion of the eyes dark; sides of the thorax darker. 9:50. Clear of the skin; wings 4 mm. in length, abdomen 10 mm. ; general color becoming darker; greens becoming brown; wings increasing in length; insect restlessly moving about on the support. 9:55. Eyes plainly striped with brownish bands; abdomen 11 mm. in length, wings 4 mm.; wings suddenly elongating near the proximal end. 9:57. Wings 7 mm. in length. 10:00. Wings 8 mm., abdomen 12 mm. in length. 10:01. Wings 9 mm., abdomen 12 mm. in length. 10:03. Wings 11 mm., abdomen 12 mm.; wings pale light green, thorax and head brownish green; abdomen pale green at base, darker at apex. 10:06. Wings 13 mm., abdomen 12 mm. 10:07. Wings 15 mm., abdomen 12 mm. 10:09. Wings 15 mm., abdomen 13 mm.; abdomen suddenly elongating at the base. 10:14. Wings 15 mm., abdomen 15 mm. 10:18. Wings 15 mm., abdomen 15 mm. 10:20. Wings 15 mm., abdomen 16 mm. 10:24. Wings 16 mm., abdomen 20 mm. 10:28. Wings 16 mm., abdomen 24 mm. 444 10:30. Wings 16 mm., abdomen 24 mm. Thorax grayish green; abdominal segments two to six nearly transparent; wings becoming transparent; stigma faint, hardly noticeable. 10:35. No increase in length of the abdomen or wings; abdomi- nal segments becoming dark near the sutures; stigma of the wings darker, now plainly noticeable; thorax olive-green; pronotum black. 10:40. First two segments of the abdomen dark green; segments three to six pale green, the apical segments the same as the proximal - ones; thorax becoming steadily darker; first trial of the wings; the insect is nearly ready to fly. F 10:45. Fully able to fly, but still delicate and without full adie coloration; no further increase in size of the abdomen or wings, but growing steadily darker in color and indications of permanent adult coloration becoming evident. 10:55. Stripes of the thorax very distinct, though no blue or other bright color has appeared; very active and using its wings fre- quently. 12:00 M. Not yet fully colored, the two apical segments of the abdomen beginning to show blue; the thoracic Stapes of green not fully developed. 2:00 P. M. Postocular spots distinet; dorsum of abdominal seg- ments eight and nine showing signs of the blue coloration. 3:00. Insect fully colored and perfectly developed in every way. ADULT Habitat—The adult Zygoptera are most frequently encountered flying along the streams or about the lakes, ponds, or marshes in which the nymphs abound. Lestes is a frequenter of the thick woods near woodland marshes; Hetaerina and Argia are most commonly encountered near rapid streams, while the remainder of the Illinois representatives of the suborder may usually be found near small lakes, ponds, or sluggish streams. Flight.—The flight is slow and uncertain, though frequently rapid enough to enable the insect to avoid the collector with surprising regu- larity. The vibration of the wings is much slower than that of the Anisoptera, and is more like that of a butterfly. Mating Habits—In summer, pairs of Zygoptera may be fre- quently found flying together.. The male grasps the female just be- hind the prothorax by means of the anal appendages. The female then doubles the body beneath the body of the male bringing the ovi- positor in contact with the accessory genitalia of the second abdomi- 445 nal segment of the male. After fertilization of the female the two continue to fly together and the female is refertilized at intervals during the egg-laying period. At the time of oviposition the two often remain together and the eggs are frequently laid while the pair are still in copula. -The time elapsing from emergence to egg-laying is not known with any certainty. The egg-laying period also, has been little studied, but it is thought to last for several weeks. Food.—Many records have been made of the destruction of mos- quitoes by Anisoptera, but no one seems to have observed or at- tempted to determine the feeding habits of the adults of Zygoptera. Dissection of a number of specimens revealed the fact that the Zy- goptera prefer small Diptera to most other food. Many remains of nematocerous Diptera were found, as the following table will show, but very few remains of other insects. Name Food eaten Date of coll. Locality 1. Hetaerina americana, ¢ Hymenoptera (?) Oct. —,1915 Muncie, Il. 2. Ischnura verticalis,g Diptera—abundant re- June 23,1915 Havana, Ill. mains 3. Ischnura verticalis, 4 Alimentary canal empty June 23,1915 Havana, Til. 4. Ischnura verticalis,9 Many small Diptera June 23,1915 Havana, Il. 5. Argia apicalis, 4 Diptera—Nematocera June —,1915 Clear L., Ky. 6. Enallagma civile, Diptera June 18,1915 Urbana, Ill. 7. Lestes vigilax, Diptera—Nematocera ..........- Bluffton, Ind. 8. Enallagma hageni, 9 Diptera—Nematocera July 18,1915 Orono, Me. 9. Enallagma antennatum Diptera—Nematocera July 18,1915 Urbana, Il. 10. Ischnura verticalis Large number of butter-July 13,1915 Lake Villa, Tl. fly scales The most common food of the adult apparently consists of small flies. No remnants were found which resembled mosquitoes, and the hymenopterous insect reported is questionably identified as such. The specimens of lepidopterous scales found in number ten were unmis- takable, and it is, therefore, evident that other insects are sometimes eaten besides Diptera*. They have also been reported to eat aphids. Enemies.—The adult Zygoptera are troubled by few enemies of any sort. Birds are perhaps the most important, but even these are not to be considered as serious enemies. Several species of hydrach- nid mites have been found attached to the adult, the most common of which are species of Arrhenurus. The mites are often conspicuous on account of their orange or reddish color, and large numbers often attach themselves to a single individual. However, they seem to cause the insect but little inconvenience. *Poulton (’06) reports that both Ephemeridae and Lepidoptera are sometimes eaten. 446 History oF THE ZYGOPTERA PALEONTOLOGY The oldest records of insects which resembled Odonata are found in the upper Carboniferous. The wings are the only parts which are well preserved, but these are very different from the wings of living Odonata. The fossil species are termed Protodonata by Handlirsch and are thought to be connected with the still more ancient forms, the Paleodictyoptera, which are the most primitive of all fossil insects. The ~ features which distinguish the Protodonata from the Paleodictyop- tera and link them to the true Odonata include the fusion of the ~ longitudinal veins at the base of the wing; the presence of numerous orderly arranged cross-veins; the appearance of interposed veins or sectors between the longitudinal veins; and, finally, the approxima- tion of the wings themselves at the base. The protodonate wing, however, differs from that of true Odonata in the lack of stigma and nodus and in the supposed absence of that typical feature, the cross- ing of the radial sector over media. It is unfortunate that more of the bodies of these interesting forms have not been preserved, for it would be advantageous to know what types of head, thorax, and abdomen they possessed. The next remains of importance are found in the Jurassic Lias of England and are much more closely related to living species than the Protodonata. They are classed as Odonata and divided into two sub- orders, the Anisozygoptera and Archizygoptera. ‘There is a single living representative of the Anisozygoptera in Epiophlebia (Paleo- phlebia) of Japan, but the Archizygoptera have no living represen- tative, and seem to be merely an offshoot from the Protodonata which apparently disappeared after a short stay in geological history. The archizygopterous wings show marked deviations from the original type of the Protodonata, and a very near approach to some of the zygopterous wings of today. The reduction in number of cells and cross-veins is characteristic of both ancient and modern forms, but the absence of the arculus and the separation of media and radius to the very base of the wing, distinguish the fossil species from any living forms. ‘The Anisozygoptera have characters common to both Gomphidae and Agrionidae, the oldest fossils being perhaps more closely related to the Gomphidae. The wings have nodus and stigma, and the radial sector plainly crosses the median vein. The degree of obliquity of the quadrangle and the presence of many interposed sectors between the longitudinal veins place them with the Agrioni- dae. ‘The head and the wings resemble those of Gomphidae in shape, 447 but the thorax and abdomen of the fossil suborder are variable and resemble both families to some degree. The true Zygoptera make their appearance in the Jurassic period. The oldest of these, comprising the families Epallagidae and Stele- opteridae, have been found in the lithographic quarries of Bavaria. The majority of species from this source belong to the Epallagidae and are fortunately in a good state of preservation. The wings are not petiolate, the nodus and stigma are present, the nodus being situ- ated near the middle of the wing and the stigma being long and nar- row. There is an oblique arculus and a more or less oblique triangle; the radial sector and the second median vein arise far distad of the nodus; and the costal field contains more than ten cross-veins proxi- mad of the nodus. The abdomen is not greatly lengthened and the legs are also normal in this regard. In the Steleopteridae the wing is distinctly petiolate; there are about five antenodal cross-veins; and the veins M, and the radial sector arise proximad of the nodus. The arculus and quadrangle are similar to those of the Agrionidae (Cal- opterygidae). The family Steleopteridae is considered to be the forerunner of the Coenagrionidae. The Tertiary deposits furnish us with the next oldest representa- tives of the group. True Zygoptera, Anisoptera, and a single family of Anisozygoptera have been found in the Florissant of Colorado and in the Tertiary deposits of Baden, Germany. Many of the species are referable to extant genera. More than eleven genera of Zy- goptera have been found in these strata. ; The first nymphs to appear in the geological record are described by Hagen from the Baltic amber and from the Tertiary of Rhein- land and Baden, Germany. Many of these forms had caudal tracheal gills and were apparently true Zygoptera. Scudder (’90) has also figured and described a nymph from the Florissant which doubtless belongs to the Zygoptera. The following tabular summary gives the characters which have been developed successively in the past, beginning with the family Dictyoneuridae of the Paleodictyoptera from which the Protodonata are thought to have been derived. 448 TABULAR SUMMARY PALEODICTYOPTERA | PROTODONATA | ODONATA pare Meganeuridae Anisozygoptera Zygoptera Dictyoneuridae Protagrionidae Paralogidae Archizygoptera Anisoptera Wings moderately broad at base Large number of ir- regular cells Subcosta ending in costa beyond the middle of the wing; not forked; no nodus : Radial sector not crossing media Radius and media not fused at base and no arculus formed Stigma absent Wings moderately broad at base Large number polygonal cells Subeosta ending about the middle forked; no nodus Cross-veins between costa and subcosta 22-50 or more Radial sectcr appar- ently not crossing media Radius and media fused but no areu- lus formed Stigma absent M, arising proximad of end of subeosta of, of the wing; not) Wings broad or nar- row at base Reduction in the number of polyg- onal cells Subecosta ending at middle of the wing; forked; no- dus present Antenodal cross- veins much re- duced, usually more than two in number Radial sector cross- ing media Radius and media fused and arculus frequently formed Areulus near the base of the wing Stigma sometimes present Stigma not support- ed by oblique eross-veins or sup- plementary sectors M, arising near. the subnodus, often slightly proximad Stigma cells numer- ous Wings broad or nar- row at base. Still greater reduc- tion in number of © polygonal cells in Zygoptera. Subcosta often end- ing proximad of ‘the middle; forked; nodus present. Antenodal cross- veins often re- duced to two in Zygoptera; more than two present in Anisoptera. Radial sector cross- ing media. Radius and media fused and arculus always formed. Arculus further dis- tad from the base. Stigma only ocea- sionally absent. Stigma supported by oblique cross- veins, supplemen- tary sectors, or both. M, arising at the subnodus or con- siderably beyond. Stigma cells few in Zygoptera. 449 TABULAR SUMMARY—continued ~ PALEODICTYOPTERA PROTODONATA — | ODONATA Meganeuridae Anisozygoptera Zygoptera Dictyoneuridae Protagrionidae Paralogidae Archizygoptera Anisoptera No quadrangle orNo quadrangle orQuadrangle and| Quadrangle always triangles triangles sometimes trian-| present; triangles gles present sometimes present. Three simple anal/Anal veins represent-|Anal veins repre-| Anal veins repre- veins present ed by a single] sented by a single] sented by a single vein vein vein. Anal field not exten- sively developed Head rounded; of considerable size Not known Not known Not known Not known Anal field not exten- sively developed Large rumbers of rows of cells be- tween all longi- tudinal veins, the rows extending far proximad Not known Not known Not known Not known Not known Anal field often ex- tended, but not le braced by loop Decided reduction in number of rows and a decided re- treat distad, leav- ing but few rows between the prox- imal portions Head rounded and of considerable size Eyes dichoptic in all families Labium cleft Abdomen slender, occasionally swol- len at tip; superi- ors leaf-like or forcipate Inferior anal ap- pendages separate Anal field extensively developed or re- duced; when ex- tended often braced by loop. Still further redue- tion and _ retreat distad. Head angular; often widened. Eyes dichoptie or holoptic. Labium cleft or en- tire. Abdomen slender, Zygoptera, or thickened, Anisop- tera; Superiors leaf-like, forcipate, or reduced to tu- bercles. Inferior anals fre- quently united in Anisoptera. 450 ONTOGENY The various parts. of the body will now be considered with ref- erence to their form during the different periods of development. Head.—The compound eyes during the life of the embryo are small and dichoptic and situated on the lateral aspect of the head. After eclosion they become larger, are sometimes expanded dorsad, but never become holoptic until the adult stage. The embryonic an- tennae are composed of three segments, the second segment being - longer than all the others together, and the third segment nothing more than a spur at the tip of the second. The increase in number . of segments takes place by division of the second, which continues to divide until the antenna has seven segments in all. There is little, if any, variation in the diameter @f the different segments of most nymphal antennae, but the proximal segments of a few are sometimes greatly developed and much larger than any of the distal ones. In the adult antennae, the apical segments are setiform and the number of segments varies from four to six. The labial palpi and the median lobe are without setae or fixed hooks. The cleft is usually obliterated after eclosion, but remains practically unchanged in the nymphs of some species. The labial palpi of the young nymph are soon after eclosion provided with fixed hooks, and the median lobe is furnishedl with rows of setae. The adults have no rows of labial setae, but these are scattered promiscuously over the surface. ‘The condition of the mandibles and maxillae is not known for the embryonic stages, but the nymphal condition is much simpler than that of the adult. In this stage the mandible is not biramous except in a few cases. The adult mandible, however, is divided into two parts, one composed of a number of teeth and the other of several cutting edges forming a Z when viewed from the edge. ‘The galea-lacinia of the nymphal maxilla is not as specialized as that of the adult, which bears a greater number of fixed hooks and setae. Thorax.—The thorax of the embryo consists of three equal seg- ments, each with a pair of appendages. Very little can be said of the sclerites in the embryonic stages, but the segments of the nymph are all about equal in size. The legs are widely separated and the in- vaginations of all furcae are usually prominent. The suture sepa- rating the proepimeron from the proepisternum is indistinct in the earlier nymphal stages, but becomes more distinct with age. In the mesothorax and metathorax, the interpleural suture is distinct in all zygopterous nymphs and in the adults of the family Agrionidae. In the Anisoptera it is indistinct in all stages. The infraepisterna and supraepisterna are separated by furrows in the nymph, but there are no definite sclerites formed until the adult stage. The mesonotum is 451 always divided in the nymph as in the adult, but seems to be simpler in structure in the nymph. The mesostigmal plates of Zygoptera are not developed until the adult stage, but the depressed area caudad of the mesoscutum in the Anisoptera is frequently present in the nymphal stages, especially in the Libellulidae. The nymph molts several times after eclosion before the rudiments of the wings appear as minute ridges on the dorsum of the mesothorax and metathorax. They develop subsequently like the wings of heterometabolous insects in general. As already noted, the crossing of the radial sector over the media can not be followed, and in only one genus, Lestes, is there any recognizable portion of the radial sector. The character of the tracheation of the wing-cases of several zygopterous sans is shown in Figures 14-17. Abdomen.—Very little can be said of the abdomen except that in both the embryo and nymph the segments are about equal in length and more or less cylindrical. Reduction in size, lengthening of the segments, and flattening of the abdomen, together with the appear- ance of dorsal and lateral spines, seem to be the developmental ten- dencies in the nymph. The accessory genitalia of the adult show no signs of development until neat the last nymphal stage, but the ovi- positor of the female appears early, at least in the Zygoptera. ‘This organ undergoes great modifications and specialization in the adult Zygoptera, but in the Anisoptera it is probably in the process of re- duction and degeneration. The caudal tracheal gills of the Zygoptera are present in the embryo, and at hatching they appear as cylindrical, jointed, cerciform appendages. Brandt (’69) says that at a still earlier stage the lateral pair of gills are fused, but this observation has not been verified. There is also a pair of smaller cerci dorso- laterad of the lateral gills, making five caudal abdominal appendages in all. All five of these are represented in the Anisoptera by short cerciform appendages which are frequently triquetal and often sharply pointed at the apex. It is important to note that these ap- pendages are never united in the nymphs of Anisoptera or in Zygop- tera, but that in the adults of Anisoptera the ventral pair is sometimes fused. In all families of Zygoptera, the superior abdominal ap- pendages, which replace the lateral gills, are greatly reduced, but in some Anisoptera, family Aeshnidae, the lateral appendages are re- placed in the adult by long, lateral, superior appendages resembling gills. A fact which sheds light on the origin of the Odonata as a whole, is the presence of lateral abdominal gills in the genus Cora of Central America and Euphea of the Old World. The rectal gills of Anisoptera have been thought to originate in the forms having tra- cheae which anastomose on entering the walls of the rectum as in most Agrionidae; but it is doubtful whether this fact is really im- = portant. Some of the most interesting modifications of structure for com- parison are found in the proventriculus. These were first investigated by Ris 452 (796), who discovered interesting correlations between the number of teeth and folds present and their supposed specializa- tion in the different families. Conditions were simplest in the nymphs of Agrionidae; more highly specialized in the Coenagrionidae, Aesh- nidae, Gomphidae, and Libellulidae. The adult structures were much ~ more complicated than those of the nymphs of the same families. The following table will suffice to show the important ontogenetic tendencies of living forms. TABLE SHOWING ONTOGENETIC TENDENCIES OF ZYGOPTERA AS COMPARED WITH ANISOPTERA Eee | NYMPH | ADULT Anisoptera Zy goptera | Anisoptera Zy goptera | Anisoptera | Zygoptera Eyes dichoptic Labium cleft Labial palpus without fixed hooks Median lobe without setae Labial palpi without setae Antennae with three segments Eyes dichoptie Labium eleft Labial palpus without fixed hooks Median lobe without setae Labial palpi without setae Antennae with three segments Eyes dichoptie Labium some- times slightly cleft, never deeply Mandibles not divided at tip Labial palp us without fixed hooks Median lobe with or with- out setae in rows Labial palpi with or with- out setae Antennae with 3-7 segments Epicranial su- ture traceable Fureae of meta- sternum often indistinct Interpleural su- ture indistinct Eyes dichoptie Labium some- times deeply cleft Mandibles al- ways divided at tip Labial pal pus with two fixed hooks Median lobe with or with- out setae in rows Labial palpi with or with- out setae Antennae with 3-7 segments Epiecranial su- ture traceable Fureae of meta- sternum never indistinet Interpleural su- ture never in- distinet Eyes sometimes ;Eyes dichoptic. dichoptic, usu- ally holoptie Labium some-|Labium usually times slightly | deeply cleft. cleft Mandibles al-|Mandibles al- ways divided| ways divided at tip at tip. Labial palpus'|Labial palpus with one fixed | with one fixed hook hook. Median lobe with setae, but not in rows Median lobe with setae, but not in rows. Labial palpi without setae Labial palpi without setae. Antennae with 4-7 segments. Antennae with 4-7 segments Epicranial —su- ture traceable with difficulty Epicranial su- ture traceable with difficulty. Fureae of meta- sternum con- cealed. Fureae of meta- sternum con- cealed r 453 TABLE SHOWING ONTOGENETIC TENDENCIES OF ZYGOPTERA AS COMPARED WITH ANISOPTERA—continued Ece | NyMPH ADULT Anisoptera Zygoptera | Anisoptera Zygoptera | Anisoptera Zygoptera Mesepisterna us- |M e se pisterna;M e sep isterna |M e se pisterna|M e se pisterna |M e se pisterna ually separated | adjacent or usually separat-| adjacent or] adjacent and| adjacent and ed separated fused fused. Abdomen cylindrical and about |Venter equal in diameter throughout; of the same diameter as the thorax No tracheal gills but a long caudal projec- | tion separated Wing-cases un-/Wing-cases un- equal in size equal in size Trachea of ra-|Trachea of ra- dial sector] dial sector not crossing media flat- tened, abdo- men much broader than thorax Tracheal gills|No tracheal present gills Ovipositor de- veloped late or wanting Reetal gills present Folds of pro- ventriculus: 4 large; 4 small crossing media Abdomen of the same diameter as the thorax Tracheal gills present Ovipositor de- veloped early Rectal gills ab- sent Folds: 4 large, 4 small; or 8 large, 8 small Wings unequal Radial sector crossing media Abdomen wid- ened at differ- ent points, us- ually of small- er diameter than thorax No tracheal gills Ovipositor some- times well de- veloped; us- ually wanting Rectal absent Folds: 4 large, and 4 small gills Wings unequal. Radial sector crossing media. Abdomen equal t hroughout; always of smaller diame- ter than tho- rax, No tracheal gills. Ovipositor al- ways well de- veloped. Rectal absent. Folds: 8 large, and 8 small. gills PHYLOGENETIC COMPARISON OF ZYGOPTERA AND ANISOPTERA Several important theories and rules of procedure should be men- tioned before undertaking a discussion of the suborders from a phylo- genetic standpoint. I.—Ontogeny repeats phylogeny. This is a w ciple and is the foundation 0 | IL—All testimony should be corroboratiz ell-recognized prin- f much phylogenetic work. re if properly under- stood; or in other words, there should be no real conflict in the phylo- genetic evidence obtained from different sources. 454 Ill. —The stem must be determined. Before an agreement can be reached as to the phylogenetic status of any form, there must be agreement as to what constitutes specialization, and what generalized conditions. Suppose, for example, that within an order of insects there are species with two types of wings—one having numerous cross-veins and the other but few; which is the more specialized? It is possible for either type to have been derived from the other or both to have arisen from a third extinct form. One may have be- come specialized “by addition” and the other “by reduction”. In this case it is evident that the stem must first be determined before the degree of specialization of either form can be stated with accuracy. 1V.—AIll possible characters should be taken into account, and a decision concerning the rank of the group should be based on a study of the whole organism. This method should be followed in view of the fact that the same degree of specialization in structure is not usually found simultaneously in different parts of the body, and it is always to be preferred to the method of determining specialization or generalization of a group of organisms by the study of a few characters. . V.—The forces which produce modification in structure should be recognized if possible and their effect upon structure determined. In the following comparisons the various characters will be con- sidered separately and, where possible, the stem form will be men- tioned and the reasons given for so regarding it. For convenience, the division of the suborders into families as outlined by Handlirsch (06-08) and Muttkowski (’10) will be followed, the Zygoptera be- ing divided into the Agrionidae and Coenagrionidae; the Anisoptera, into the Aeshnidae, Gomphidae, and Libellulidae. Egg 1.—Egegs of the Odonata are of two types; one long and some- what cylindrical in shape, the other ellipsoidal and short. The dif- ferences in shape are the result of different methods of oviposition. The ellipsoidal form would seem to be the more primitive, judging from a general knowledge of the eggs of various orders of insects. No definite proof of this can be given, but a comparison with the eggs of the Apterygota and the lower Arthropoda indicates that the ellipsoid is probably the stem type. This is, however, in direct con- tradiction to the argument found in the reduction of the ovipositor, since the species with specialized or reduced ovipositors lay ellipsoidal eggs. Disregarding the latter argument and considering the ellipsoi- 455 dal egg as the primitive type, the series from lowest to highest would be something like the following: Libellulidae, Gomphidae, Aeshni- dae, Agrionidae, and Coenagrionidae. Nymph 2.—The most striking differences in nymphal characters are found in the shape of the body. Zygoptera are without doubt near- est the primitive Campodea type, and Anisoptera show a marked deviation which is possibly due to the habits of life. This interpreta- tion is supported by the embryonic stage, in which the body shape is essentially campodeiform in both suborders. 3.—The compound eyes of all forms are specialized, but the line of a is not difficult to follow. The primitive type is found in the embryo, which has small circular eyes on the lateral aspects of the head. The nearest approach to this is found in the eyes of zygop- terous nymphs; the farthest away from it, in the Anisoptera, where the eyes show a tendency to become dorsal in position. The cause of the modification is unknown, but may be due in part to their habits, the Anisoptera being mud-inhabiting to a large extent and needing eyes on the dorsum of the head. Another cause may possibly be found in the accelerated development of the greatly enlarged eyes of the adult. In respect to shape and position of the compound eyes, then, the Anisoptera should be regarded as the more highly special- ized group. 4.—The antennae show important lines of development. The primitive antennae of the embryo consist of three segments, the sec- ond segment being the longest. A great lengthening of the first seg- ment is the main line of specialization, and this occurs only in Zygoptera in the family Agrionidae. The antennae nearest the em- bryonic type are found inthe Gomphidae; next in order are the Aeshnidae, then the Libellulidae, and, finally, the Coenagrionidae and the Agrionidae. 5.—The labium shows the more primitive condition in Zygoptera, where the median lobe is deeply cleft in the family Agrionidae. Gra- dations in complexity are found in a reduction in the depth of the cleft, and the line of specialization may be followed through the fol- lowing series, beginning with the least specialized: Agrionidae, Coenagrionidae ; Gomphidae, Aeshnidae and Libellulidae. 6.—Mental setae are lacking in the embryo and also in the nymphs of Aeshnidae, Gomphidae, Agrionidae, and a few Coenagrionidae. The cause of the production of mental setae is unknown. There 456 seems to be greater specialization in the shape of the labial palpi or lateral arms in the Coenagrionidae, notably the Lestinae, than in any other group. The simpler types are found in the Aeshnidae, Gomphi- dae, and Agrionidae, and a highly specialized form again in the Libel- lulidae. 7.—The condition of the maxillae and the mandibles in species existing prior to the present time can only be surmised, since there are no embryological or paleontological data on the subject. These appendages are so nearly alike in shape in the two suborders that no comparison can be profitably made. 8.—The primitive prothorax, according to both paleontological and embryological evidence, was a simple ring of the same size as the mesothorax and metathorax. Specialized conditions are found in the Anisoptera where, owing to the size of the head and the growth of the compound eyes, the cephalic part of the pronotum is depressed. The condition of the prothorax is probably primitive in Zygoptera. The sclerites are not as distinct in the Anisoptera as in the Zygoptera, indicating that obsolescense of the sutures has begun in this suborder. 9.—The next feature of note is found in the interpleural suture. Stages of disappearance occur in all Anisoptera, the suture being completely lost in the Libellulidae and perfectly distinct in all nymphs of Zygoptera. The cause of this modification is unknown, but it is probably due to the excessive development of the wing muscles with- in the thorax. In respect to this feature, then, the primitive forms are found in the Zygoptera; the specialized, in the Anisoptera. 10.—Another modification is found in the disappearance in the Libellulidae of the metafurcal invaginations. The primitive condi- tion or stem form is unknown, as is also the cause of the disap- pearance. It is probable, however, that the type with distinct in- vaginations is the more generalized, which places the Zygoptera, the Aeshnidae, and the Gomphidae much below the Libellulidae in position. 11.—In the shape of the wing-pads, the Anisoptera show more conformity to the generalized types occurring in Plecoptera and Or- thoptera than do the Zygoptera; and they must be regarded as gen- eralized in this respect. 12,—The simplest abdomen, judging from embryological studies, is a cylindrical portion of about the same diameter as the thorax. The abdomen is much modified in all Anisoptera, where it is enlarged and the venter flattened. The Zygoptera are generalized in this re- spect, and a series showing progressive specialization in this single feature would be as follows: Agrionidae, Coenagrionidae, Aeshni- dae, Gomphidae, Libellulidae. 457 13.—The caudal tracheal gills of Zygoptera must be considered a simple or stem character. This view is supported by much evidence from embryological studies and the presence of one or two living forms in which the gills are decidedly cerciform and cylindrical. The modification into flat plates is undoubtedly specialization, but the re- duction of the abdominal appendages in the Anisoptera indicates further specialization of a different kind. Changes in shape of the zygopterous appendages are probably due to a change from terrestrial to aquatic habits very early in the history of the group. If we con- sider that the anisopterous appendage has been derived by progres- sive reduction, the following should be the order of development: cylindrical cerci, flattened cerci, and reduction of cerci to short ap- pendages similar to those in all Anisoptera. If, however, the gills be regarded as derived from shorter caudal appendages, the Anisoptera have the primitive types and the Zygoptera are highly specialized in their elongate, flattened appendages. The presence of cylindrical cerci as a primitive character seems to have the greatest amount of embryological evidence to support it. 14.—The abdominal gills of Cora and Euphea of the Zygoptera also afford comparative evidence as to the age of this suborder. Here there are remnants of lateral, cylindrical gills on the abdominal seg- ments. There seem to be embryological data sufficient to prove that these lateral gills represent the appendages of forms more primitive even than the Insecta. 15.—The oldest fossil Odonata showing ovipositors had the char- acters of both Zygoptera and Anisoptera, and it is probable that the stem forms had true ovipositors. The simplest type of ovipositor among living Odonata is found in the nymphs of Zygoptera and consists of a number of similar valves. The reason for the reduction of the ovipositor in the adults of Anisoptera lies in the acquisition of the aquatic habit and the consequent difficulty of depositing eggs in plant tissue. It is reported that some Zygoptera do not insert the egg in the plant but merely press it against the plant and allow it to drop to the bottom; and this appears to be a transition stage from the endophytic to the exophytic method of oviposition. Reduction of the gonapophyses, then, means specialization, and the order would be—Zygoptera, generalized; Anisoptera, specialized. Adult 16.—So many different lines of specialization seem to have taken place in the development of the head capsule of the adult that it is 458 almost impossible to arrive at any conclusion as to its simplicity or complexity. Suffice it to say that paleontological and embryological data prove that there are primitive types in both Zygoptera and An- isoptera. In the holoptic condition of the compound eyes, however, there is a more definite character. As already stated, the primitive type is dichoptic; and beginning with this condition, which we find most closely approximated in the Zygoptera, there are all degrees of dichoptic and holoptic states. The cause of the modification is prob- ably due, in the adult, to the increased power of vision made neces- ~ sary by the greatly increased powers of flight and the fact that the insect captures its prey while on the wing. An excellent series of - specializations is to be had in the following families, the Zygoptera being the more generalized: Agrionidae, Coenagrionidae; Gomphi- dae, Aeshnidae, and Libellulidae. 17.—The antennae, as already noted, show marked reduction in size from those of the nymphs. The nearest approaches to the primi- tive. seven-segmented condition are found in the Libellulidae and some of the Aeshnidae, where six segments are often encountered. Most representatives of the remaining families have the segments quite consistently reduced to four. The adults of the Agrionidae have the most highly specialized antennae; and in a series showing increasing specialization the Libellulidae would be the more gener- alized. The following is such a series based upon antennal structure: Libellulidae, Aeshnidae, Gomphidae, Coenagrionidae, and Agri- onidae. 18.—The front shows great deviation from the simpler forms in the majority of the Anisoptera, and the mound-like elevation of this part is characteristic of most families of this suborder. 19.—The mandibles of the adult have apparently undergone no modification of importance in the different families. They are so nearly alike in all groups that a comparison will not be attempted. 20.—The maxillae of the adult have likewise undergone little modification in the different families, but the form nearest the primi- tive type present in Plecoptera nymphs is found in the Gomphidae. 21.—The labium shows the same deviations from the primitive condition as were described for the nymph. Looking upon the depth of the median cleft as a measure of generalization, the Agrionidae would be considered as the more generalized. Next in order are the Coenagrionidae and, following these, the Aeshnidae, Gomphidae, and Libellulidae. The labial palpi retain about the same degree of specialization that occurs in the nymphs; and the same sequence of family specialization as has been described for the nymphs is present in the adults. 459 22.—As regards the form of the microthorax, no stem can be de- termined, but it is probable that there has been much more specializa- tion in the Anisoptera than in the Zygoptera. 23.—The degree of complexity of the prothorax as a whole is difficult to determine. Many sexual modifications occur in the adults which must be considered as secondary characters having little bear- ing on phylogeny. The distinctness of the propleural suture, how- ever, is of some value. In Zygoptera, this suture is most distinct in the Coenagrionidae (Lestinae) and is moderately so in the Agrioni- dae. In the Anisoptera it is most distinct in the Aeshnidae, but is as a rule indistinct in other families. According to this character the Zygoptera seem to be generalized; the Anisoptera specialized. 24.—In the mesothorax and metathorax the most important fea- _ ture, aside from the wing structure, is to be found in the interpleural suture. As already mentioned, this suture shows no sign of disap- pearance in any of the nymphs of Zygoptera, and still remains undi- minished in distinctness in the adults of the family Agrionidae. In the Coenagrionidae, however, the interpleural suture becomes obsolete in great measure. In both nymphs and adults of Anisoptera, it is indistinct. The degree of its distinctness is therefore an excellent character for determining the degree of specialization or generaliza- tion of the species and consideration of this fact alone leads to the conclusion that the Zygoptera are the more generalized. 25.—The varying degrees of approximation of the mesepisterna and the metepimera indicate an entirely different line of development from that shown in 24. The primitive condition is one in which the two mesepisterna and metepimera are separated by considerable inter- vals, as has been shown for the nymphs. The approximation of the metepimera on the ventro-meson is a much later development and does not appear until the adult stage. Nevertheless, nearly the same line of specialization occurs as in the former case, the simplest conditions being found in the Aeshnidae and the Agrionidae, the more complex in the Gomphidae, Libellulidae, and Coenagrionidae. 26.—The development of the mesothoracic spiracles indicates that the Libellulidae, again, are the most specialized, with the Agrionidae and Aeshnidae at the bottom of the series. The size of the spiracles in Libellulidae and the degree of their approximation on the dorso- meson warrant this assumption, the primitive types being small in size and rather widely separated, as in Zygoptera and some Aeshnidae. 27.—A line of specialization is found in the length of the thorax caudad of the metacoxae. In this the Coenagrionidae and Agrionidae are decidedly the more specialized. 460 28.—More use has been made of the wings and wing venation in following out genealogical development than of any other single por- tion of the body of the dragon-fly. The evidence is conflicting in many respects, and in coming to conclusions all characters must be taken into account. ‘The most noticeable feature of the wing venation is the crossing of the longitudinal veins Rs and M. ‘This condition is so unique that it was doubted or denied for a long time, and not until it was traced from its beginning in the tracheae of the nymph _ was it generally accepted as true. Many of the changes in the wing venation may be considered as the result of stress on particular por- | tions of the wing surface. The development has followed two lines of specialization; one of them a reductive process, exemplified in the Zygoptera, the other additive, exemplified in the acquisition of im- portant wing-braces in the wings of Anisoptera. The main points regarding the specialization of the odonate wing are stated in the following tabulation. 2h B pepe Generalized conditions Developmental tendencies & 2 ra) BS Bs af aS ALAR 1. Wings of equal size and Wings of unequal size and Yes Yes venation. venation. 2. Wings not petiolate. Wings petiolate. Yes Yes 3. Nodus not retracted; Retraction of the nodus to- Yes Yes near the middle. wards the base. 4. No reduction in number General reduction in number Yes ? of cross-veins. of cross-veins. 5. Arculus near the base of Retreat of the arculus distad Yes Yes the wing. from base. 6. No reduction in the Reduction in number of an- Yes ? number of antenodals. | tenodal cross-veins. 7. No reduction in the Reduction in number of Yes ? number of postnodals. postnodal cross-veins. 8. Rs traceable throughout Rs not traceable throughout No Yes its course. its course. pee g. Mz not arising distad of M, arising. distad of the Yes ? the nodus. nodus. 10. Rs separating from M, Rs separating from M, dis- Yes ? near the nodus. tad of the nodus. 461 Fm > Ze EE Generalized conditions Developmental tendencies 5 S = Ry ao as eee II. Quadrangle triangular. Quadrangle rectangular. Yes No 12. M; and M, not uniting M, and M, uniting distad of Yes Yes distad of the arculus. the arculus. 13. Media at the top of the Media descending the arcu- Yes Yes arculus. lus. 14. No development of the Development of the anal Yes Yes anal loop. loop. 15. No matching of the Matching of the transverse Yes Yes transverse cross-veins. cross-veins. 16. Pentagonal cells numer- Reduction in number of Yes Yes ous. pentagonal cells. 17. Little reduction in the Reduction in the number of Yes Yes number of rows of rows of cross-veins be- cells and little retreat tween all longitudinal distad. veins and retreat distad of the rows. 18. Nodus and arculus not Approximation of the nodus Yes Yes approximated. and arculus. 19. Stigma long. Stigma short. Yes Yes 20. Stigma sometimes ab- Stigma always present. Yes Yes sent. The different families are specialized in the characters listed under the figures following them: — ' Coenagrionidae.—2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 16, 17, 18, 19, 20. Agrionidae.—1I, 15, 16. Aeshnide.—2, 5, ITI. Gomphidae.—1, 5, 7, II. Libellulidae. —1, 12, 13, 14. From the above it will be seen that in wing venation the family Coenagrionidae is by far the most highly specialized, while the Agrion- idae, Aeshnidae, and Gomphidae are about equally specialized, and the Libellulidae are intermediate in position. 29.—The primitive abdomen consisted of a cylindrical portion of the same diameter as the thorax; and the same is now essentially true of the nymphs of Zygoptera. In the adults, however, the diameter 462 of the segments has been reduced as compared with that of the thorax. In the Anisoptera there are other modifications besides the reduction in diameter. Here, the abdomen is sometimes triangular in cross-sec- tion, and different portions of the abdomen of the same species have different diameters. Considering shape alone, the following line of development may be recognized, beginning with the more generalized : Agrionidae, Coenagrionidae, Aeshnidae, Libellulidae, and Gom- . phidae. This order of specialization is followed throughout in the abdomen. 30.—The approximation of the terga on the ventro-meson, is a mark of specialization most frequently found in the Anisoptera, as is also the appearance of the secondary ridges on the terga. 31.—The anal appendages of the abdomen are interesting, and the line of specialization indicated by them seems to coincide in general with that already outlined for the suborders in 29 and 30. The series has already been given for the two groups in paragraph 13. Within the Anisoptera, two different lines are found, both probably represent- ing specialization. In one of these the inferiors are fused, as in the Libellulidae ; in the other the superiors are enlarged and expanded, as in the Aeshnidae. In the Zygoptera the forcipate appendages of the Agrionidae probably represent the most primitive forms, and the short and frequently greatly modified appendages of the Coenagrionidae, the more highly specialized. 32.—Accessory male genitalia of the second segment are important. The statement that this organ has been derived from the sexual organs of the progoneates is substantiated by the reported connection of the proximal end of the penis with the visceral cavity. This occurs in Zygoptera and seems not to have been observed in the Anisoptera, the connection supposedly having been lost through specialization. Further specialization has been suggested in the tracheation of the appendages, which occurs in some Anisoptera according to Backhoff (710) but not in Zygoptera. Other differences indicating specialization in Anisoptera are to be noted in the segmentation of the penis and. in the position and connection of the seminal vesicle with the latter. The structure of the hamules and the genital lobes, and of the portions of the genitalia arising from the third abdominal segment, seems to be simpler in the Zygoptera and not so much reduced or changed from the original plan of the sterna of these segments. The tip of the intro- mittent organ is much simpler in structure in the families of Zygoptera. 33.—As mentioned in paragraph 15, the presence of the ovipositor in the early stages of the nymphs of Zygoptera and its absence in the nymphs of Anisoptera suggest that the anisopterous appendages have 463 been reduced from a primitive form similar to that of Zygoptera. This, together with the evidence furnished by extinct species where adults with wing venation similar to that of the Anisoptera had ovipositors, proves fairly conclusively that the extant species without ovipositors have undergone specialization by reduction. ~ 34.—One of the most complete lines of specialization has been de- termined by Ris (’96) for the structure of the proventriculus. He found what he considered a primitive condition in the Zygoptera (Agrionidae) in which there are sixteen internal folds. Specializa- tion takes place by reduction, and there are eight folds in the Lestinae, four in Gomphus and Aeshna, and none in Libellulidae, there being instead four large symmetrical teeth. 35.—Specialization among the Anisoptera seems to be still further indicated by the habits of the group, especially their habits of migra- tion. The mere fact of migration is not important; but the method of flying in companies and particularly of so flying that there are reg- ularly spaced intervals between the individuals is something which, if true, is unique in this order and in the class Insecta. Considering the preceding characters as a whole, it will be found that there are two orders of specialization which apparently proceed in opposite directions. One of these begins with the Agrionidae of the suborder Zygoptera and ends with the Libellulidae of the Anisop- tera; and the other begins with the Libellulidae and ends with the Agrionidae. The characters mentioned in the various paragraphs will now be assembled for a comparison of the number of generalized features in each family. The families are listed below, and are usually or frequently generalized in the characters discussed in the paragraphs the numbers of which are placed opposite. Agrionidae.—2, 3, 5, 6, 8, 9, 10, 12, 13, 14, 15, 16, 18, 21, 22, 23, 24, 25, 28, 20, 30, 31, 32, 33, 34, 35. Coenagrionidae.—2, 3, 5, 8, 9, 10, 12, 13, 14, 15, 16, 18, 21, 22, 23, 24, 26, 29, 30, 31, 32, 33, 34, 35. Aeshnidae.—1, 4, 6, 10, II, 15, 17, 25, 27, 28. Gomphidae.—1, 4, 6, 10, II, 17, 20, 27, 28. Libellulidae —1, 11, 17, 27, 28. From this it will be seen that the most generalized family is the Agrionidae. ‘The evidence is such that it can not be doubted, and it points to some form of the Agrionidae or related family as the stem type. The following genealogical tree, based partly on Handlirsch (06-08), has been constructed after taking into account all existing evidence. Distance to the right indicates specialization; vertical dis- tance, time. 464 euajdosAzosiuy arpuonsy aepimowseuaog, aepluysay aepryduioy sVplN[[aqrT Eras Periods ura 2 Banshee 2 Cainozoie 7 J cretaseone A gk pate SE Triassic PIEMOpOZOK4 Paleozoic Carboniferous Tt | CLASSIFICATION Some of the more important features used in the classification of the nymphs of Zygoptera include the characters of the labium and antennae, the nature of the caudal gills, and the armature of the lateral keels. The classification of the adults depends upon the wing venation and the anal appendages of the male, ‘as well as on such characters as the mesostigmal plates of the female, color, and the like. The number of species occurring, or probably occurring, within the state is forty-two, as follows. Those without asterisk have been taken in adjoining states by other collectors; those with one have 465 been reported from Illinois; and those with two have been collected by the writer or seen in collections actually made within the state. ** Agrion aequabile (Say) ** Agrion maculatum Beauvais ** FH etaerina americana (Fabri- ; cius ) ** Hetaerina titia (Drury) *Lestes congener Hagen *Lestes disjunctus Selys Lestes eurinus Say **Lestes forcipatus Rambur *Lestes inaequalis Walsh **T estes rectangularis Say ** Testes uncatus Kirby **D estes unguiculatus Hagen **T estes vigilax Hagen ** Argia apicalis (Say) Argia fumipennis (Burmeis- ter) ** Argia moesta putrida (Hagen) *Argia sedula (Hagen) ** Argia tibialis (Rambur) ** Argia violacea (Hagen) **Fnallagma antennatum (Say) *Enallagma aspersum (Hagen) **Fnallagma calverti Morse **Fnallagma carunculatum Morse ** Fnallagma civile (Hagen) Enallagma cyathigerum (Char- pentier ) Enallagma divagans Selys Enallagma doubledayi Selys **Fnallagma ebrium (Hagen) **Fnallagma exsulans (Hagen) **Fnallagma geminatum Kellicott **Fnallagma hageni (Walsh) Enallagma piscinarium W il- liamson **Fnallagma pollutum (Hagen) ** Fnallagma signatum (Hagen) **Fnallagma traviatum Selys ** Nehalennia irene Hagen ** Amphiagrion saucium (Bur- meister ) **Chromagrion conditum (Ha- gen) Ischnura kellicotti Williamson **T schnura posita (Hagen) **7 schnura verticalis (Say) ** Anomalagrion hastatum (Say) The division of the suborder into families and the arrangement of genera followed by Muttkowski (’10) have been adopted and are herewith reproduced, including only the genera that occur in Illinois. Family Agrionidae Lestinae Coenagrionidae Coenz.grioninae Subfamily { Agrioninae Genus Agrion Hetaerina Lestes Argia Enallagma Nehalennia Amphiagrion Chromagrion Ischnura Anomalagrion ’ 466 In the following descriptions “length” refers to the length of the body without appendages, and does not include caudal gills, anal appendages, or antennae. In the color descriptions, where suitable material was at hand, the colors were matched with colors given by Ridgway in his “Color Standards and Color Nomenclature” (’12), and the names of colors which appear in parentheses are from that author. Family AGRIONIDAE The nymphs of this family are easily distinguished from those of the Coenagrionidae. he three-sided gills, the deeply cleft median lobe of the labium, the large basal segments of the antennae, the un- equal length of the gills, and the heavy and sprawling appearance of the legs are characteristic. The adults are, as a rule, bright or strikingly colored, such colors as metallic green and carmine being common. eeccetstin tei 9 mm. Ihenohh ok cull si accra serteieetoen toe 7 mm. Wadthroterlls ccc ciucerstseert sistas 1.8 mm. Length of median lobe............. 2.3 mm. Width of median lobe.......... .8-1.6 mm. Described from three specimens in the collection of the State Laboratory of Natural History, collected at Havana, IIl., June 30, 1897. The nymph has not been reared, but the specimens were deter- mined from a description given by Walker. Adult; Male.—Color, blue and black. Head blue and black, buff below; labium buff, the median lobe subtriangular, the apical cleft narrow; distal segment of the labial palpi pale ; postclypeus black except the lateral margins, anteclypeus, labrum, mandibles, their trochantins, genae, and the transverse area above the clypeus blue; lateral ocelli with a small blue spot cephalad of each, the remainder of the front and vertex black; pale line caudad of the ocellar area distinct, the ends narrowly separated from the large blue, cunei- form postocular spots; occiput pale except a transverse black line bor- dering the postocular spots. Thorax blue and black; pronotum mostly black, with a large blue spot on each median lobe, the caudal margin of the caudal lobe and 527 most of the cephalic lobe blue; proepimera blue, the dorsal border with a broad black stripe; mesothorax with a blue dorsal carina, the black stripe on each side occupying about half of each supraepisternum; mesopleural suture covered by a black stripe which is suddenly widened caudad of the infraepisterna; dorsal third of the mesepimeron black; metapleural suture with a black spot adjacent to the wing bases; paraptera black, the cephalic margins blue; remainder of the pleura blue ; postcoxal areas buff ; legs striped biack and blue, the coxae largely blue; trochanters blue, dark above; femora with black stripes occupy- ing the whole of the dorsum, but not extending ventrad far enough to include either row of setae; cephalic margins of all femoral black stripes emarginate at the proximal end; cephalic half of the tibiae black, the stripe including the cephalo-ventral row of setae; tarsi uniform brown, the segments darker at the distal end; wings with 12-13 post- nodal cross-veins in the front wing and 10-11 in the hind; M, arising between the fifth and sixth postnodal cross-veins or near the fifth in the front wing, and between the fourth and fifth in the hind; stigma small, pale brown, and surmounting slightly less than a single cell. Abdomen blue and black ; terga 1-5 inclusive, blue with the excep- tion of a black spot on the dorsum of one, a subapical dorsal spot and apical ring on two, and apical spots and rings on 3-5 ; caudal half of the dorsum of six and caudal three-fourths of seven, black; terga eight and nine blue; tenth tergum black above, pale buff on the lateral mar- gins; first sternum pale; sterna 3-8 black; parameres black and not reaching the apex of the segment; anal appendages short (Figs. 200, 207), the superiors blunt, shorter than the inferiors, but without the conspicuous tubercle of civile and carunculatum, inferiors slender, acute and black at the tips. Female.—Color, blue, but paler than that of the male. Head: the blue of the male is replaced by brown or buff. Thorax similar to that of the male, but the blue is frequently re- placed by brown or buff. Abdomen blue and black, the first tergum with a black basal spot as in the male, spot of the second tergum connected with the apical ring and a line on the meson extending to the base of the sclerite; terga 3-6 with narrow dorsal black lines widened suddenly near the apices of the segments and occupying the caudal three-fourths; seventh ter- gum with a similar but broader dorsal line; caudal half of the dorsum of the eighth, and all of the ninth and tenth black; lateral margins of all terga pale; sterna 3-7 black; one, two, eight, and ten pale; ovi- positor pale, the lateral valves broad. 528 Measurements Mrentethira ome ate eho. 6o8/ oc wre 33-35 mm Tenet Ss, Faces. pis coech scene 34 mm. Length of abdomen, ¢............. 26 mm. length of abdonien, 9: +)... eee 26 mm. Length of hind wings, @............ 19 mm. Length of hind wings, 9........... 21 mm. Width: of hind wines, od 2 ..scies seen - 4 mm. Width of hind wings, @......... 4-4.5 mm. This species is closely related to caruncluatum, civile, doubledayt, and cyathigerum. ‘The adult male is czsily distinguished from those species by means of the anal appendages; the female, less easily, by means of the mesostigmal plates. Illinois is within the range of the species and it probably occurs within the state although there seems to be no record of its presence. A large number of adults of both sexes have been examined, all in the collection of Mr. E. B. Williamson. ENALLAGMA CARUNCULATUM Morse Nymph.—Color, green or buff. : Head about twice as broad as long, the caudo-lateral margins not projecting strongly, but with a few strong setae; antennae with the third segment longest, the second longer than the first, the first two and the proximal portion of the third darker than the rest ; mental setae of the median lobe three, and sometimes a small fourth on each side; lateral setae six; marginal setae of the median lobe eight or nine on each side; labium extending caudad between the first and second pair of coxae. Thorax: legs pale, the femora with very faint or no preapical rings and distinct rows of moderately heavy setae; tibiae and tarsi with the usual apical scales and ventral setae; metathoracic wing-cases extending about to the middle of the fourth abdominal segment. Abdomen with well-developed lateral keels, the keel of the first segment with three or four setae; the second, with eight to twelve; third, with about eleven; fourth, with thirteen to fifteen; fifth, eighteen to twenty; sixth, eighteen to twenty; seventh, twelve to fourteen; and the eighth with about fourteen; on the fifth and sixth keels the setae are bunched at the apex, with sometimes as many as three together ; venter of the abdomen entirely without small setae on the cephalic seg- ments, but usually with long hair-like setae on the dorsum of segments 529 two, three, and four. In mature nymphs there is an indefinite, dark dorsal stripe extending from near the apex of the third segment to the seventh or eighth; gills (Fig. 70) transparent, lanceolate, with a broad, usually pale, opaque stripe along the axis from the base to near the tip; dorsal marginal setae of the median gills usually more than twenty in number and extending one-third the length of the gill from the base, the ventral setae of the same gill consisting of only a few setae and extending half as far as the dorsal row; ventral marginal setae of the lateral gills of similar extent to the dorsal setae of the median gill; apical margins usually without setae or hairs; ovipositor of the female extending to the middle of the tenth abdominal segment and the lateral valves with about four heavy setae on the ventral margin. Measurements Went od ee tterce cin folic aied 13.5-14 mm. Wenethiotabdomen... 2... sa... -- 8-9 mm. enatuvot oullseees seep o—O IN: Width-ot ills ee eee. bees 1.2 mm. Length of metathoraciec wing-eases. .3.6 mm. Length of median lobe............. 2.5 mm. Width of median lobe............ 5-2 mm. Adult; Male.—Color, dark blue or buff and black. Head blue or buff and black, the labium buff, the median lobe subtriangular, the palpus moderately narrow; antennae entirely black, the first segment paler at the apex; postclypeus with a large, shining black spot, the ventro-lateral margins pale; anteclypeus, and labrum except a dorso-mesal black spot and a dorso-lateral spot on each side, pale; exposed portions of the mandibles, their trochantins, the genae, and a transverse stripe above the clypeus, pale; remainder of the front and vertex dull black; postocular spots oval, buff or blue, and not usually connected with the stripe caudad of the ocellar area; occiput and postgenal regions pale except a black stripe caudo-ventrad of the postocular spots. Thorax blue or buff and black, the pronotum dull black with a transverse median stripe on the cephalic lobe, the caudal margin of the caudal lobe and small crescentic spots on the lateral margins of the median lobe buff or blue; dorsal third of the proepimera black, the dorsal suture indistinct, the remainder of the sclerite buff or blue; ceph- alo-lateral angles of the mesostigmal plates elevated, the elevated por- tion pale; pale stripe of the mesosupraepisternum regular, the margins parallel and straight, the stripe extending from the cephalic margin 530 nearly to the paraptera; black stripe of the mesopleural suture widest just caudad of the mesinfraepisternum, extending onto and covering about the dorsal third of that sclerite, the stripe continuous at the caudal extremity with a narrow stripe extending ventrad along the caudal margin of the mesepimeron to the interpleural fold; metapleural suture with a black spot adjacent to the wing bases; remainder of the thorax buff or blue; legs striped, buff and black, the coxae and trochanters usually pale, the femora with broad dorsal stripes from bases to apices; tibiae with dorsal stripes covering about half the dorsal — surface and including the cephalo-ventral row of setae; tarsi and claws pale, black at the tips, the claws very long; wings with nine to eleven - postnodal cross-veins and with M, arising near the fifth postnodal cross-vein in the front wing and between four and five in the hind wing. : Abdomen black and blue or buff; terga 1-6, inclusive, blue or buff, except a small black basal spot on one, a black apical ring and dorsal spot occupying half the second and third terga, another covering slightly more than half the fourth, two-thirds of the fifth and sixth, and all of the seventh except the narrow lateral marginal stripes and a basal ring; dorsum of the tenth tergum black; eighth and ninth terga entirely blue or buff; sterna one and 3-8 with a median black line; anal appendages (Figs. 194, 205) short, the superiors usually black, blunt, and with a narrow notch on the dorsum cephalad of but near the dorso- caudal angle; inferiors paler, the black apices directed strongly dorsad and frequently in contact with the superiors. Female.—Color similar to that of the male. Head similar to that of the male; the postocular spots are, how- ever, considerably smaller. Thorax similar to that of the male. Abdomen with the dorsum of terga 1-10 with broad, dorsal dark stripes, widened subapically on segments 2-4 inclusive, the pale color occupying the larger part of the lateral surfaces of all terga as lateral stripes which are continuous with the broad uninterrupted basal rings on segments 4—7 and the interrupted ring of the third tergum; sterna 1-8 with a mesal black line from the bases to near the apices, the eighth sternum with a long apical seta; lateral valves of the ovipositor broad, pale, the ventral margins serrate from apex nearly to base, the pro- styles darker on the apical half. Measurements Denothy (Guise casos keto an ee 33 mm. Bien gthy. 4p eri: dtr ante ciel eernaetors arate 32 mm. 531 Length of abdomen, ¢............. 26 mm. Length of abdomen, @2............. 25 mm, Length of hind wings, ¢............ 19 mm. Length of hind wings, 9............ 19 mm. Waidthvor bind wits; O\.i5.a2.5 sacs. 4 mm. Width of bind! wings, 2.4)... es. le se 4 mm. An inhabitant of the lake regions of Illinois, the nymphs prefer- ring floating vegetation or rank growth along the banks of ponds or lakes of considerable size, though they are occasionally to be en- countered in the larger and clearer streams. - The color of the recently emerged adult is buff or cream-color and biack, and the blue is much slower in appearing than in other species. ENALLAGMA CIVILE (Hagen) Nymph.—Color, green or buff. Head about twice as broad as long, the caudo-lateral angles not projecting caudad or laterad, but armed with short setae; antennae with the third segment longest, the first shorter than the second, the - first two segments and the proximal portion of the third dark brown, the remainder of the third and the distal segments pale; labium ex- tending just caudad of the first pair of coxae, the median lobe with three or four mental setae, the labial palpi with five or six lateral setae and a row of seven or eight small setae on the margin of the median lobe. Thorax pale buff or green; legs very pale, the preapical femoral rings indistinct, the femora with a dorsal and lateral row of setae and scales near the tips; metathoracic wing-cases extending caudad to the middle of the fourth abdominal segment. Abdomen pale buff or green, frequently with an indefinite darker stripe on the dorsum of segments 3-7, the cuticle sparsely provided with minute setae, which are usually lacking on the venter of the cephalic segments; dorsum of two, three, and four with long hair-like setae; lateral keels well developed and setose, the first without setae, the second with a row of about eleven, the third with twelve, the fourth with sixteen, fifth with eighteen to twenty, sixth with fifteen to sixteen, seventh with twelve to fourteen, and the eighth with a straight row of about nine setae; gills (Fig. 75) lanceolate, colorless and usually without pigment except in the smaller tracheae, the margins very transparent; dorsal marginal setae of the median gill extending less than half the length of the gill from the base, and composed of more than twenty setae; ventral row of the lateral gills slightly longer 532 and about half the length of the gills; female ovipositor extending to the middle of the tenth abdominal segment, the ventral margins of the lateral valves setose, the row consisting of about eight stout setae and a number of hair-like ones. Measurements Tienoth ee ceneeeias sa anise ete 15 mm. hengeth ofabdomen’....2- sates aar-- 10 mm. benethiotvarils it cec.'./t on cate. beers 6 mm. Widthvot Gustine 2. icjen press 1.8-2.1 mm. Length of metathoracie wing-cases. .4.5 mm. Length of median lobe............. 3.1 mm. Width of median lobe.......... .8-2.3 mm. Adult; Male.—Color, dark blue and black. Head blue and black; mouth-parts buff, the median lobe of the labium subtriangular, with a shallow, acute, median cleft, the labial palpi much broader at the proximal end than at the apex; antennae dark brown or black; postclypeus with a shining black spot on the meson; anteclypeus shining yellow; labrum shining yellow with a black ‘dorso-mesal spot; exposed portions of the mandibles, trochantins, and genae pale, and a pale stripe above the clypeus extending dorsad to the level of the antennal fossae; remainder of the front and vertex dull black; postocular spots oval or subcuneiform, the pale line caudad of the ocellar area not distinct; occiput and postgenae yellow, except a transverse black stripe caudo-ventrad of the postocular spots; com- pound eyes dark brown or black. Thorax blue and black, the black usually metallic; pronotum black, the cephalic lobe with a pale transverse line, the median lobe with a pale spot on the lateral margins and the caudal lobe also with pale margins; proepimera with black corsal borders, pale below ; meso- stigmal plates subquadrangular, the cephalo-lateral angles somewhat elevated, though not as much so as in carunculatum, and the lateral half covered by a yellow spot; dorsal black stripe regular and covering nearly half of each supraepisternum; pale stripe of the supraepisterna broadest dorsad of the mesinfraepisterna, extending nearly to the paraptera; mesopleural black stripe of the suture narrowed cephalad of the wing bases, broadest shortly caudad of the mesinfraepisterna and extending across and covering about one-third of the latter; caudal margin of the mesepimera black to the level of the interpleural suture ; metapleural suture with a black spot cephalad of the wing bases; re- mainder of the pleura blue, the postcoxal areas buff, becoming polli- nose; paraptera black, the cephalic margins pale and a pale spot below the lateral angles; legs striped, the coxae and trochanters pale, the 533 femora with stripes on the dorsum, the tibiae with black stripes occupy- ing half the dorsa, but not reaching the apices of the segments; tarsi and claws pale, dark at the tip, the claws notched at a considerable dis- tance proximad of the tip; wings with nine or ten postnodal cross-veins, the vein M, arising between the fourth and fifth postnodal cross-veins, usually near the fifth, in the front wing, and between the fourth and fifth in the hind wing. Abdomen blue and black, the cephalic terga largely blue, the caudal ones darker and frequently becoming pollinose with age; terga 1-6, inclusive, blue except a small basal spot on the dorsum of one and black shield-shaped apical spots and apical rings on 2-6; dorsal black spot of the sixth tergum occupying about half the dorsum, those of 2-5 about one-fourth; dorsum of the seventh and tenth terga black except the lateral margins and a narrow, basal, interrupted ring on the seventh ; all of the eighth and ninth terga blue; sterna 2-10 with a black median line; anal appendages (Figs. 198, 103) short, the superiors blunt, with a narrow cleft or notch just ventrad of the apex; inferiors usually black and shorter, the black tips directed obliquely caudad and dorsad and frequently in contact with the superiors. Female.—Color similar to that of the male. Head similar to that of the male. Thorax similar to that of the male except in the color of the legs, which are usually lighter, the dorsal stripes of the femora never ex- tending to the proximal ends of those segments. Abdomen: the dorsum of all terga have a black longitudinal stripe from the bases to the apices and a short, narrow, apical, black ring; margins of all terga yellow or blue, the pale color extending onto the dorsum at the bases of segments 2-6, but always forming interrupted rings and never connected across the dorsum (Fig. 92) as in carun- culatum (Fig. 91); sterna 1-8 with a mesal line from bases to apices, the apex of the eighth sternum with a heavy seta which is darker at the tip than at the base; anal appendages of the usual form, the ovi- positor with yellow lateral valves, the ventral margins of which are serrate from the apex to near the base; prostyles brown, dark at the tip. Measurements Pietiot hve aware same cccretete sister ors rs 29-32 mm. TOTTI Se ect tea nuts telecine achat 30-32 mm. Length of abdomen, ¢.......... 23-24 mm. Length of abdomen, 9.......... 23-24 mm. Toength of hindwings, 6 3a 312200 1 17 mm. Length of hind wings, @........ 19-20 mm. Width of hind wings, ¢.......... 3.5-4 mm. Width of hind wings, @.......... 3.5-4 mm. 534 A common species at Urbana. It was not taken at Havana, where carunculatum was abundant, nor at Lake Villa, where both caruncu- latum and hageni were common. ‘The females of these closely allied species have been determined from material collected in the above localities. A study has also been made of specimens taken in copula, in the collection of Mr. E. B. Williamson. The imago emerges at Urbana as early as June 13 and apparently continues to emerge throughout the season. Nymphs taken late in. July emerged shortly after, and another lot, collected at Lexington, Ky., emerged as late as August 18, 1915. There is a possibility that. the species has two broods a year. ENALLAGMA CYATHIGERUM (Charpentier) Nymph.—Color, buff. Head elliptical, the caudo-lateral angles rounded and sparsely setose ; antennae of the usual form, the second segment slightly longer than the first; labium broad, and extending caudad to the mesocoxae; mental setae four, the proximal seta of both rows more than half as long as the remaining ones; lateral setae five or six; marginal setae of the median lobe four or five. Thorax: femora without conspicuous rows of small setae; wing- cases extending caudad to the middle of the third abdominal segment. Abdomen with distinct lateral keels all of which are setose in- cluding those of the first segment; the size of the setae gradually increases caudad, and on each lateral surface of the ninth segment there is a row of setae in line with the lateral keels with two or more setae grouped together at the caudal end of the row; gills (Fig. 71) clear and without cuticular pigmentation though reported by Lucas (’00: 103) to have one or more narrow cross-bands beyond the middle; dorsal and lateral gills with closely placed marginal setae which extend more than half-way from the bases to the apices of the gills; tracheal branches few in number and usually larger than are found in civile or carunculatum, ovipositor of the female extending caudad to the caudal margin of the tenth abdominal segment. Measurements Perret emerey eprint erie cate SiGe cong eMail. Length of abdomen ................. 9 mm. encthole oul seen ctnce error: 5 mm. Widthrok ills irises tere ee mee reries 1.5 mm. Length of metathoracie wing-cases....4 mm. Length of median lobe............. 2.5 mm. Width of median lobe ?.<:....-. .75-2 mm. 535 Described from three nymphal exuvia from France (Martin), obtained from Mr. E. B. Williamson. Adult; Male.—Color, pale blue and black. Head black, blue, and buff; mouth-parts buff; median lobe sub- triangular, the proximal segment of the labial palpi broad, the distal segment pale; antennae dark, the second segment much longer than the first; postclypeus black except the lateral margins and the ventral margin, the anteclypeus, labrum, mandibles, and the transverse stripe above the fronto-clypeal suture blue; genae, pale yellow; remainder of the front and vertex black; postocular spots large, blue, the margins of the spots irregular and the spots narrowly separated from the narrow stripe caudad of the ocellar area; occiput, except a stripe caudad of the postocular spots and the postgenae, pale blue. Thorax: pronotum largely black, the cephalic lobe with the cephalic half blue, median lobes with large oval blue spots; proepimera and episterna blue with black dorsal borders; mesostigmal plates narrow and more than half pale; dorsal carina with the black stripe which covers it also covering one-half of each supraepisternum; black stripe of the mesopleural suture narrowed ‘considerably caudad and covering about one-third of the mesinfraepisterna ; remainder of the mesopleura, except a small spot on the mesopleural suture near the wing bases, pale blue; postcoxal areas yellowish blue; legs with blue coxae and trochanters, the trochanters dark on the dorsum; femora with a single black stripe on each dorsum, the stripe broken by a small spot at the base; cephalic half of the dorsum of the tibiae with black longitudinal stripes; tarsi pale yellow, darker at the distal ends; wings with twelve postnodal cross-veins in the front wing and ten in the hind; stigma surmounting less than a single cell, pale. Abdomen blue and black; first tergum with small basal and smaller lateral black spots; second tergum blue with a subelliptical apical spot and an apical ring; terga three, four, and five with apical spots connected with the apical rings; apical half of the sixth and about four-fifths of the dorsum of the seventh with broad black stripes expanded caudad but not reaching the margins of the terga; terga eight and nine pale; dorsum of ten black, the caudal margin distinctly incised on the meson, the lateral surfaces of the segment pale yellow; first sternum pale, 3-8, inclusive, black; anal appendages (Figs. 201, 208) black and brown, the superiors short, bent ventrad and some- what acute at the apex; inferiors much longer than the superiors and black at the tips. Female.—Color in general similar to that of the male, the blue, however, replaced by yellow. 536 Head and thorax similar to those of the male except that they — are somewhat lighter in color; mesostigmal plates as shown in Figure 213. Abdomen with broad longitudinal stripes on the second tergum which are much expanded near the caudal margin; terga 3-7 with narrow longitudinal stripes, all of which are expanded near the caudal margin, the longitudinal stripe of eight much reduced near the cephalic margin (Fig. 93); anal appendages of the usual type; ovipositor short, the lateral valves pale, ventral margins slightly serrate; pro- styles short and blunt. Measurements Wen Gt, Sis sustehs, sys fol cvebetayaystadeaiersiets 31-32 mm. Mien ethic Og Se veel eacrs tone ee esos 31-32 mm. Length of abdomen, ¢............. 24 mm. eneth of abdomen Or. . os cee. cer 26 mm. Length of hind wings, ¢......... 19-21 mm. ' Length of hind wings, 2?............ 20 mm. Width of hind wings, 3............. 4 mm. Widthtor ‘hind wines) 90052. eee 4 mm. This species is most closely related to calverti, from which the female differs in having more black on the dorsum of the eighth tergum and in the characters of the mesostigmal plates. ‘The male may be distinguished by means of the anal appendages. Described from a number of both sexes in the collection of Mr. E. B. Williamson. The species has not been reported from Illinois, but probably occurs here. ENALLAGMA DIVAGANS Selys Nymph.—Unknown. Adult; Male.—Color, blue and black. Head blue and black; labium pale, median lobe subtriangular, the labial palpi including the distal segment pale, the proximal segment narrow; antennae dark, the first two segments subequal, the first pale at the tip; postclypeus black, anteclypeus except a small dorso- mesal black spot, the mandibles, their trochantins, genae, and a trans- verse area above the fronto-clypeal suture pale blue; remainder of the front black; vertex with pale subcuneiform postocular spots, the remainder of the dorsal portion black; occiput and postgenae pale blue or buff with the exception of a large black spot laterad of the occipital foramen on each side. 5387 Thorax blue and black ; pronotum black, cephalic lobe largely blue, the median lobes with large spots adjacent to the proepimera, and the caudal lobe with small spots on the lateral angles and one on the meson; proepimera distinct blue and with a dorsal, crescentic, black spot; mesostigmal plates largely blue, the mesal angles black; mesosupra- episterna black, with blue longitudinal stripes from the cephalic mar- gins to the wing bases, the stripe slightly widened cephalad, narrowed at the middle, and widened again caudad ; mesopleural suture covered by a black stripe which occupies a portion of the supraepisterna and the epimera, being widest about the middle, narrowed near the wing bases, extending cephalad across the infraepisterna and covering about one half of those sclerites; remainder of the pleura blue, with the ex- ception of spots on the interpleural fold and metapleural suture ad- jacent to the wing bases; legs buff or pale blue and black; coxae blue with a black basal spot on the cephalic surfaces; dorsum of the trochanters dark, remainder pale; femora with slight dorsal carina, the dorsal longitudinal stripes usually covering the carinae, but the stripes sometimes divided by a pale line on the carina, and emarginate at the proximal end; tibiae mostly pale with faint cephalo-dorsal stripes or row of dashes, the ventral surfaces with black spots at the base and apex; tarsi pale, the segments darker at the distal end; wings with twelve postnodal cross-veins in the front wing and ten in the hind wing; stigma pale, surmounting less than a single cell; M, arising near the fifth postnodal cross-vein in the front wing and between three and four in the hind wing. Abdomen blue and black with a touch of bronze; first and second terga blue, with black, dorsal, longitudinal stripes, the first with a very narrow subapical ring of black which does not reach the lateral margins ; longitudinal stripe of the second tergum expanded subapically and the tergum with a broader apical ring extending from the meson half-way to the lateral margins; terga 3-7 with dorsal longitudinal stripes which are contracted to the meson near the cephalic margin, but widen subapically and unite with the black apical rings; terga eight and nine entirely blue; dorsum of the tenth tergum entirely black, the venter pale blue or buff; anal appendages (Fig. 190) short, black, the superiors bilobed, the dorsal arm knob-like, the ventral lobe more slender; inferiors slender, directed obliquely dorsad and frequently in contact with the ventral arm of the superiors; first sternum pale, 3-9 black. 538 Female.—Color similar to that of the male. Head similar to that of the male. Thorax: black stripe of the mesopleural eae divided by a line of brown; mesostigmal plates as shown in Figure 2 Abdomen: terga 1-7, inclusive, similar to care esp ota terga of the male, the lateral blue stripes of the margin becoming dull brown on the apical segments; eighth tergum black, with pale blue lateral spots on the caudal margin; tergum nine blue, with two short dorso-lateral black stripes which fuse at the base of the meson; tergum ten blue; anal appendages dark brown, ovipositor pale buff, the prostyles short and blunt. Measurements 1D(\eVean Oba cies ate as Mea elon nnn an ees 29-33 mm. Wen Ct iON tars teres wasnt dees 32 mm. Length of abdomen, ¢@........... 24-28 mm. Length of abdomen, @............. 26 mm. Length of hind wings, ¢........ 17-18 mm. Length of hind wings, 9............ 18 mm. Width of hind wings, $............ 3.5 mm. Width of hind wings, @............ 3.5 mm. This species is very closely related to exsulans, the male differing principally in the possession of blue on the eighth tergum and in the character of the anal appendages. The female can not be separated from exsulans except by the mesostigmal plates. It is, however, a much more slender and delicate insect. Described from eighteen males and one female in the collection of Mr. E. B. Williamson. A rare species, reported from Ohio, but not yet taken in Illinois by collectors. ENALLAGMA DOUBLEDAYI Selys Nymph.—Unknown. Adult; Male.—Color, light blue and black. Head blue and yellowish and black; antennae uniform brown, the second segment slightly longer than the first; anteclypeus and labrum shining yellow; exposed portions of the mandibles, their trochantins, genae, and the front dorsad of the clypeus to the level of the antennal fossae pale ; remainder of the front black; postocular spots smail, the narrow stripe caudad of the ocelli distinct ; occiput and post- genae pale; compound eyes dark brown. 539 Thorax black, blue, and yellowish green; pronotum black, the cephalic lobe, a small spot on each median lobe, and the caudal margin of the caudal lobe pale; proepimera and episterna pale, the noto- epimeral suture indistinct; paraptera black; mesothorax with a broad black dorsal stripe, the stripe covering about one-third of the meso- supraepisterna on each side; remainder of the thorax, including the postcoxal areas, buff with the exception of small dark spots on the metapleural sutures near the wing bases; legs black and yellow, the coxae and trochanters pale, darker on the cephalic surfaces; femora each with a broad black dorsal stripe which frequently includes one row of setae; tibiae with longitudinal stripes on the cephalic surfaces; wings with about ten postnodal cross-veins in the front wing and eight in the hind one; M, arising between the fifth and sixth postnodal cross-veins in the front wing and between the fourth and fifth in the hind wing. Abdomen blue and black; terga 1-10 blue except a small basal spot on the first, a hastate spot on the second, an apical spot and marginal ring on the second to the fifth, the apical half or two-fifths of the dorsum of the sixth, dorsum of the seventh (excepting a narrow interrupted basal ring), and the tenth, which are pale; anal appendages (Figs. 169,175) similar to those of Be and civile, but the superiors differ (compare Fig. 169 with Figs. 176 and 179) in having a smaller pale tubercle at the end and in Bene siuch wider proximad of the tubercle. Female.—Color, similar to that of the male. Head similar to that of the male. Thorax : mesostigmal plates (Fig. 226) similar to those of civile, but the caudal margins concave, instead of convex as in the latter. Abdomen: terga I-10 with broad dorsal dark stripes and basal in- terrupted rings, the lateral margins pale; anal appendages of the usual type and the ovipositor pale, the ventral margins of the lateral valves serrate. Measurements hensive coma a deer tate OL Imm: LO GTaReg CE ACO ante erecta een ERT 31 mm. Length of abdomen, ¢............. 25 mm. Length of abdomen, @............. 24 mm. Length of hind wings, ¢........... 17 mm. Length of hind wings, @? ........... 18 mm. 540 Described from a number of specimens in the collection of E. B.. Williamson. This species has not been reported from Illinois. It has been collected in Ohio and was originally described from Florida. It is possible that it may occur occasionally in southern Illinois. ENALLAGMA EBRIUM (Hagen) Nymph.—Not available for study. Adult; Male.-—Color, blue and black. Head black and blue; mouth-parts pale, the labium with a sub- triangular median lobe; labial palpi buff, the distal segment dark at the apex; antennae black except the tips of the first and second seg- ments; postclypeus black; anteclypeus, labrum, exposed portions of the mandibles, their trochantins, genae, and a transverse stripe above the clypeus, pale; remainder of the front and vertex black; postocular spots large, subcuneiform, the margins irregular; occiput and post- genae pale except a transverse black stripe caudo-ventrad of the post- ocular spots. Thorax blue and black; pronotum black, the cephalic lobe with a pale transverse stripe, median lobes with pale spots on the lateral and caudal margins of the caudal lobe; dorsal border of the proepimera black, the ventral two-thirds pale; mesostigmal plates elongate, the lateral angles covered with a pale spot and slightly elevated, though not as much as in carunculatum or civile; dorsal mesothoracic stripe occupying about one-third of each supraepisternum, the lateral margins parallel; pale stripe of the supraepisterna extending from the cephalic margin to near the paraptera, widest above the infraepisternum; black stripe of the mesopleural suture widest just caudad of the infraepi- sternum, and extending across and occupying about one-half of that sclerite ; caudal margin of the metepistetna black and a black spot on the metapleural sutures cephalad of the wing bases; remainder of the pleura blue, the postcoxal areas buff; paraptera black, trapezoidal, the cephalic margins and a spot just below the lateral angles pale; legs striped, black and buff, the femora and coxae pale, the entire dorsum of the femora black except a small spot near the base, fre- quently appearing as an emargination of the black dorsal stripe; tibiae with a black stripe from base to near the apex, occupying half or less of the dorsal aspect and often including the cephalo-ventral row of setae; tarsi and claws pale, dark at the tips; wings with nine to ten postnodal cross-veins in the front wing; vein M, arising between the 541 fourth and fifth postnodal cross-veins in the front wing and between three and four in the hind wing. Abdomen blue and black; terga largely blue, with black spots on the base of the first and the apices of 2—6 inclusive, all of the dorsum of seven blue except a basal interrupted ring, and all of ten blue; terga eight and nine blue; sterna 3-8 with mesal lines of black from the cephalic to near the caudal margins; anal appendages (Figs. 189, 196) short, pale, the superiors bifid, the two arms equal in length; dorsal arm of the superior appendages black at the tip and forming a blunt hook; ventral arm pale and nearly straight ; inferior appendages pale, dark at the tips and about as long as the superiors. Female.—Color, black and yellow or blue. Head similar to that of the male, the blue, however, sometimes replaced by yellow. Thorax similar to that of the male; mesostigmal plates as shown in Figure 227. Abdomen with broad dorsal stripes on segments 2—10, the stripes contracted to the meson on the bases of terga 3-7 inclusive, and widened subapically on segments 2—7, the widened portion not reach- ing the lateral margins; first tergum pale, with a black spot at the base; sterna 1-8 with black median stripes; ovipositor of the usual form and not reaching caudad of the tenth segment, the ventral mar- gins of the lateral valves feebly serrate. Measurements en ote g cas aera sie ene ee ato ore Seer 29 mm GTC OR A Mle 5 Oe! 6S) OR ia 0 Eee tere 29 mm. Length of abdomen, ¢.......... 23-25 mm. Length of abdomen, ?.......)...... 24 mm. Length of hind wings, @........ 16-17 mm. Length of hind wings, @........... 18 mm. Width of hind wings, ¢............. 4 mm. Width of hind wings, @............. 4 mm.” The anal appendages of the male distinguish the species from closely alliéd members of the genus, and the mesostigmal plates of the females are also characteristic. Described from a number of males from Illinois in the collection of the State Laboratory of Natural History, and from females in the collection of E. B. Williamson. 542 ENALLAGMA EXSULANS (Hagen) Nymph.—Color, dark brown or greenish. Head slightly broader than long, the caudo-lateral angles pro- jecting caudad and provided with heavy setae; second antennal seg- mient shorter than the first, the first two darker than the remaining ones and pilose; labium extending just caudad of the procoxae, mental setae three in number; lateral setae four or five, and six or seven marginal setae on the median lobe. Thorax: legs with a few hair-like setae, the femora each with a preapical ring of brown and the tibiae with the usual scales at the tip; apices of the third tarsal segments and the apices of the claws dark; metathoracic wing-cases extending caudad to the fourth abdominal segment. Abdomen slender, the cuticle provided with minute setae and minute brown spots; lateral keels well developed on segments 1-8, the keels on segments 4—8 and the lateral apex of segment nine with small groups of two to five setae; gills (Figs. 53, 77, 77a) broadly lanceolate, broadest beyond the middle, usually heavily pigmented on the proximal two-thirds, the area of infuscation being followed by. two large clear spots on each side of the axis, the distal end of the gill being dark, the extreme tip white; marginal setae of the median gill consisting of a dorsal row extending from the base to the light spots, or nearly two-thirds the length of the gills, and ventral marginal setae of the lateral gills of similar extent; apical margins of all gills hairy; smaller tracheae forming alga-like patches; ovipositor extend- ing to the middle of the tenth abdominal segment. Measurements TuOTI UM «oars cetera & be ys Sisto ee 12-13.5 mm. Genethiot abdomen: =. 2m. eeree 9-10 mm. enethiots culls 2. eee ore eee 5.5-7 mm. Wadthr ofioilllst. i cex ces teeter ate 1.8-2 mm. Length of median lobe.............. 2 mm. Width of median lobe.......... .6-1.8 mm. Adult; Male.—Color, pale blue, black, and brown. Head pale blue and black; median lobe:of the labium buff, sub- triangular, the cleft obtuse at the base; antennae entirely black; post- clypeus black, shining, the anteclypeus pale and the labrum with a transverse black stripe on the dorsal margin; exposed portions of the mandibles, their trochantins, genae, and a transverse area between 543 the compound eyes and above the clypeus, pale blue; remainder of the front, and the vertex, black; postocular spots and the postgenae and ecciput yellow. Thorax blue and black; pronotum largely black, the cephalic lobe blue; large spots on each mesal lobe and a smaller one on each, near the meson, blue, and a blue triangular mesal spot on the caudal lobe; proepimera largely blue, the dorsal sutures indistinct and covered with black; mesostigmal plates elongate, the lateral angles covered by a blue spot; dorsal carina with a broad, black stripe, which covers also about one-half of the mesosupraepisterna on each side; the dorsal stripe is followed on each supraepisternum by a narrower blue stripe extend- ing from the cephalic margin caudad to near the paraptera, the stripe being narrowed at both ends; the black stripe of the mesopleural suture is broad, extends ventrad well onto the metepimera, and in younger specimens is divided by a brown line which is directly over the suture; dorsal third of the mesinfraepisterna, and spots on the metapleural sutures near the wing bases, dark brown or black; re- mainder of the pleura blue, postcoxal areas brownish or buff; legs pale blue, or brown and black, the coxae and trochanters pale, the femora each with a faint dorsal carina on one side of which is an indefi- nite line and on the other a row of spots, the hind femora, however, often entirely pale ; tarsi and claws pale, dark at the tips; wings with ten to eleven postnodal cross-veins and M.,, arising between the fourth and fifth postnodal cross-veins in the front wings and between three and four in the hind wing. Abdomen blue and black, the dorsum of terga 1-9 and ten with longitudinal black stripes from base to apex, widened subapically on segments 2—7 and narrowed to the meson on the apex of the eighth tergum; lateral surfaces of terga 1-8 and ten, all of nine, narrow apical ring on one, narrow basal ring on three, and a broad basal ring on four, five, and six, blue or pale; anal appendages (Figs. 203, 210) black, the superiors bifurcate, the dorsal arms shortest and with minute points directed mesad; inferiors paler and shorter than the superiors. Female.—Color, pale green (pale viridine green), black, and brown, tip of the abdomen blue. Head similar to that of the male except that the postocular spots are connected with the narrow stripe caudad of the ocelli, and the genae and stripe above the clypeus are usually more or less orange in color. 544 Thorax with the brown of the mesopleural dark stripe covering’ - the suture more conspicuous and persistent than it is in the male; mesostigmal plates as shown in Figure 220. Abdomen with broad dorsal stripes on segments 1-8, the stripe on nine being reduced to two triangular spots at the base of the tergum, the remainder being blue in color; tergum ten blue; lateral surfaces of terga 2-8 and narrow interrupted basal rings on segments 3-8 pale green; sterna 2-8 with black mesal lines, the eighth with a long apical seta; Ovipositor and anal appendages of the usual form, the lateral valves of the ovipositor blue or pale and serrate on the ventral margins ; prostyles dark brown. Measurements Whenoth, Worreiesh ts aciee wees eter 35 mm. Wen gthy 390% pci ates. ayes sister 32 mm. enethiotabdomen vic acter eiee 29 mm. Length of abdomen, 9............. 26 mm. Length of hind wings, ¢........... 19 mm. Length of hind wings, @........... 20 mm. Widthi of ding swans sede. reese «ele 4 mm. IWidthio® bind wanes Gis. . el ...... 665: 4 mm. One of the commonest species in Illinois, occurring in all localities. Next to Jschnura verticalis it may be considered as the most abundant. The nymphs may be collected in slow streams, permanent ponds, or lakes, and prefer the clear water. They emerge in central Illinois 556 as early as the tenth of May and the greatest number of adults appear on the wing about June 1. The latest emergence which is recorded is one on June 25, 1915. This gives a period of emergence of at least a month and a half. Specimens have been seen from Havana, Lake Villa, Murgie: Peoria, and Urbana. ENALLAGMA TRAVIATUM Selys Nymph.—Color, very dark brown. Head about one-third as long as broad, dark in color; caudo- lateral margins projecting caudad, studded with short setae; antennae very slender, the first two segments with setae and of much greater diameter than the remaining ones, the third segment longest, the second decidedly shorter than the first; labium extending slightly cau- dad of the first pair of coxae; mental setae two, with sometimes a rudi- mentary third, lateral setae four; marginal setae of the median lobe six or seven. Thorax: lateral portions of the prothorax and the metapleura darker than the dorsum of the thorax; legs slender, the coxae dark brown, femora almost wholly devoid of setae, but with very distinct preapical brown rings; tibiae with setae which are rather closely set, especially towards the apices; tarsi pale. Abdomen brown, darker immediately above and below the lateral keels; cuticle with a few minute setae, but lacking minute black spots entirely ; lateral keels feebly developed and without heavy setae, there being instead a few setae near the apices of the keels; gills (Fig. 55) rather narrowly lanceolate, the median gill entirely without heavy setae on the dorsal margin; lateral gills with the ventral marginal row of setae extending one-half or less of the length of the gills; basal two-fifths or one-half of the gills uniform dark brown, the pigmented area followed by a broad white or clear band extending from margin to margin and including the axes; beyond the clear portions there are frequently one or two brown transverse stripes, the apex of the gills being without pigment; ovipositor extending caudad to the apex of the tenth sternum, the ventral margins of the lateral valves with one or two heavy setae and a number of hairs. Measurements Tien ethers ciiccvuate custo oie erste eve ates eens 11 mm. Dengthiof apdomen enc cmasciicce eee 8 mm. Hengthiof gillscc se. ceases siete 6 mm. Widthvof gillse) 25.5 eaten etre ets 1 mm. 557 Length of metathoracie wing-cases...3.5 mm. Length of median lobe .............. 2 mm. Width of median lobe.......... .5-1.3 mm. Adult; Male.—Color, pale blue and black. Head blue and black; labium buff, the median lobe with a broad median cleft; distal segment of the labial palpi pale; antennae brown, the first segment sometimes with the cephalic half blue; postclypeus blue with a small black spot on each side; anteclypeus blue; labrum blue with a black dorso-mesal spot ; exposed portion of the mandibles, their trochantins, genae, and the front from the fronto-clypeal suture dorsad to the median ocellus, blue; lateral ocelli with small blue spots ventrad of them, and a similar spot between the ocelli; remainder of the front black; postocular spots very large, forming equilateral triangles and occupying most of the dorsal portion of the occiput, the spots bounded caudad by a very narrow black band and separated from the com- pound eyes by a band of similar width; the narrow stripe caudad of the ocellar area is indistinct ; occiput and postgenae pale blue. Thorax blue and black; pronotum blue and black, the cephalic lobe with a transverse line of blue on the caudal margin, the median lobes with elongate blue spots, contiguous on the meson, and semi- crescentic spots of the same color; proepimera and proepisterna brown or pale; mesothorax with the narrow black stripe covering the dorsal carina but frequently divided there by a line of brown; black stripe of the mesopleural suture reduced to a line on the suture; mesinfraepi- sterna with black crescentic marks on the dorsal borders; remainder of the pleura blue with the exception of small spots on the interpleural folds and metapleural sutures adjacent to the wing bases; postcoxal areas pale; paraptera black, crescentic, the cephalic margins and lateral angles blue; legs striped, pale blue or buff and black, the coxae and trochanters blue, the femora blue with broad dorsal black stripes which are frequently interrupted at the base by a pale spot; tibiae pale blue and buff with a short dorsal black stripe or none, the tarsi pale, black at the tips ; claws deeply bifid and black at the tips; wings with ten postnodal cross-veins in the front wing and eight in the hind one; M, arising between the fourth and fifth postnodal cross-veins in the front wing and between three and four in the hind one; stigma small, subellip- tical, and surmounting less than a single cell. Abdomen blue and metallic black, the dorsum of the first tergum with a small black basal spot about half the length of the tergum; sec- ond tergum with a black, apical, shield-shaped spot, the spot extending to the cephalic margin and narrowed at this point to a line on the me- 558 son; terga 3-7, inclusive, with longitudinal black stripes widened subap- ically and narrowed basally, the lateral margins of the terga pale; terga eight and nine usually entirely blue, the eighth sometimes with a basal spot on the dorsum; tenth tergum black; anal appendages (Figs. 199, 206) short and black, the superiors slightly longer than the inferiors and appearing slightly knobbed at the apices when seen in lateral pro- file; viewed from above, the superior appendages are seen to have broad basal lobes which are often contiguous on the meson; inferior, appendages short, subconical, and directed obliquely dorsad; first sternum pale, 3-8 black, the tenth pale. Female.—Color similar to that of the male. Head similar to that of the male except that the front is paler and the spots ventrad of the lateral ocelli are larger and connect with the pale color of the ventral portions of the front; the black borders of the postocular spots are narrower than those of the male. Thorax: dorsal stripe divided by a line of brown on the carina; mesostigmal plates pale blue, the lateral angles elevated (Fig. 214), and a sinuate dark stripe on the supraepisterna just caudad of. the plates; mesopleural suture with a distinct spot cephalad of the wing bases and the black of the infraepisterna reduced to narrow dorsal lines ; postnodal cross-veins of the front wing ten to eleven, of the hind wing nine to ten. Abdomen: dorsum of the first tergum with a “black basal spot, 2-7, inclusive, with narrow dorsal longitudinal stripes, widened sud- denly near the caudal margins and narrowed to the meson near the cephalic margins; tergum eight blue with a narrow dorsal stripe ex- tending a little over half the length of the tergum from the base, (Fig. 94); ninth and tenth terga blue; anal appendages of the usual form; ovipositor with broad, blue, lateral valves; first and second sterna pale, with black mesal lines, 3-8, inclusive, black. Measurements Ten Ota icc ph eine sesmaveyeteter tae ee 31 mm. emethe Oh: EU jae, nee eta east eke ene ekece ol mm. Wenethvot abdomenyide tects). 25 mm. Length of abdomen, @.............. 25 mm. Length of hind wings, Qa Ri oateens 17 mm. Length of hind WINGS, 2 ........-. 18.5 mm. Width of hind wings, B>smcuhen atte eit 3.29 mm. Width of hind wings, 2?............ 3.9 mm. 559 This species was collected at Carbondale, Ill., June, 1915, and was reared at that time. It has not been reported elsewhere in the state but doubtless occurs about glacial lakes and ponds. The nymph differs from that of exsulans chiefly in the darker color. In all the specimens studied the labium has only two men- tal setae as compared with three in exsulans. The gills show con- siderable difference in the shape and pigmentation, particularly of the apical portions. The adult is most closely related to exsulans, but both sexes may be distinguished by the reduced amount of black on the mesopleural suture, the greater amount of blue on the front, and the exceedingly large postocular spots. Genus NEHALENNIA Selys The nymph of the only representative of this genus occurring in Illinois is characterized by its peculiar type of gills, in which the tracheae are much more numerous near the widest portion of the gill than elsewhere. ; The dominant color of the adult is metallic green or bronze, the mesepisterna being entirely without pale stripes and the pronotum without pale spots. The female has the caudal lobe of the pronotum trilobed and the eighth sternum is without the ventral apical seta. The sternites at the base of the cephalic pair of gonapophyses arc minute and scarcely visible. NEHALENNIA IRENE Hagen Nymph.—Color, brown or green. Head oval in outline, the caudo-lateral angles with but few setae; antennae with the second segment longer than the first, the second segment and proximal third of three dark in color; labium, when folded, extending nearly to the mesocoxae, with a single large mental seta and a smaller one alongside; lateral setae five, and the lateral margins of the median lobe with about five small setae. Thorax: femora and tibiae with rows of sparsely placed setae, the preapical rings of brown on the femora very indistinct; apical tibial scales present; wing-cases extending nearly to the apex of the fourth abdominal segment. Abdomen slender, with feeble lateral keels, the cephalic two or three without setae, the caudal ones with not more than six or seven; cuticle of the abdomen with small whitish spots on a darker back- ground; gills (Fig. 61) much broader beyond the middle, the lateral 560 gills with ten to twelve black cuticular spots on the margins and a distinct arcuate cross-band just beyond the middle; tracheal branches much more numerous beyond the middle of the gill; marginal setae large and widely separated, the ventral row of the lateral gills ex- tending about half the length of the gill from the base and the distal setae much farther apart than the proximal; ovipositor usually ex- tending beyond the apex of the tenth segment. Measurements enol sireaeeene sietieselentet eters eee 10-11 mm. Den gthr Otc ba oMlenasiierseyicmieleisiensteias 8 mm. engthvoticills een ei one 44.5 mm. Wildthyotigoulls: ocr saste std tmiccheties 1 mm. Length of median lobe ......... 1.5 leer Width of median lobe............. 1.25 mm. Described from three specimens obtained from Dr. E. M. Walker, and labeled Toronto, Ont., May 31, 1913. Adult; Male—Color, metallic green and pale blue. Head metallic green above, buff below; median lobe buff, the cleft large and rounded at the base; distal segments of the labial palpi dark at the tips; antennae black, the second segment with a pale ring at the middle; postclypeus shining black, the anteclypeus buff; labrum pale yellow with a dorsal, transverse, shining black stripe about one- third the width of the piece; exposed portions of the mandibles, the trochantins, genae, and the front from the fronto-clypeal suture dorsad to the antennal fossae, shining yellow; remainder of the front, vertex, and a large portion of the occiput, metallic green; postgenae black, with a pale stripe beneath the compound eyes which is continuous with the yellow of the genae ; compound eves brown. Thorax metallic green and pale blue; pronotum metallic green without paler spots, the margin of the caudal lobe entire; proepimera buff-colored; dorsal carina and the mesopleural suture lined with black ; mesosupraepisterna and the mesepimera except the cephalo-ven- tral shoulders metallic green; dorsal margin and about the ventral half of the mesinfraepisterna pale, the remainder metallic green; remainder of the mesopleura and metapleura except a green triangle adjacent to the wing base on the metepimera, buff or pale blue; postcoxal areas buff or pale blue; legs pale, striped with black; coxae and tro- chanters pale, all the femora with dorsal stripes extending from the apices nearly to the bases, and the front femora with a short cephalo- 561 ventral stripe including the cephalo-ventral row of setae; tibiae with long dorsal stripes extending from a point slightly distad of the femora to near the apices of the segments; tarsi and claws pale except at the apices; wings short, the postnodal cross-veins ten in the front wing, nine in the hind wing; M, arising between the fourth and fifth postnodal cross-veins in the front wing and between three and four in the hind wing. Abdomen metallic green and pale blue; terga 1-7, inclusive, metallic green above, with broad, lateral, pale stripes on one and two, and narrow lateral stripes and interrupted basal rings on 3-7; eighth tergum green on the dorsum except at the apex, where there is a tri- angle of blue, the lateral angles of which are continuous with the broad blue stripes on the lateral surfaces; ninth and tenth terga blue with green basal triangles on each side of the meson; anal appendages (Figs.159,160) with the superiors small and tuberculate, the inferiors much larger than the superiors and toothed at the apices. Female.—Color, metallic green cr bronze, and yellow. Head similar to that of the male except that within the dark area of the front there is a pale-spot ventrad of each antennal fossa. Thorax differing from that of the male in having the caudal lobe of the pronotum emarginate on each side of the meson, the piece being trilobed ; the mesostigmal plates (Fig. 182) have the mesal margins strongly elevated and projecting dorsad; the front wings have nine to ten postnodal cross-veins, the hind wings usually nine. Abdomen with terga 1-8, inclusive, greenish bronze, the lateral margins pale; ninth tergum green above, with an apical blue triangle and blue lateral stripes; tergum ten blue, with two small green tri- angles at the base; anal appendages of the usual type; ovipositor, in- cluding prostyles, extending beyond the apices of the anal appendages, the prostyles dark. Measurements NETL o Ua Maes tan ete kere eR hare sunny 27 mm TEN CTH OM EWE AIM RIES Eee OS Melba 26 mm. Length of abdomen, ¢............ 21.5 mm. Length of abdomen, @............. 21 mm. Length of hind wings, ¢........... 15 mm. Length of hind wings, @........... 15 mm. Width of hind wings, ¢............. 4 mm. Width of hind wings, 9............ 4 mm. The species is apparently limited to the northern third of the state. It was abundant at Lake Villa, July 13, 1915, and was also taken at Freeport July 8, 1915. 562 Genus AMPHIAGRION Selys The nymph of the only species of the genus known to occur in Illinois is easily distinguished from other genera by means of the projecting caudo-lateral angles of the head. The gills are without cuticular pigment and are decidedly ovate in shape. The adults are red or brown in color. The stigma of both front and hind wings is turned obliquely to the long axis of the wing and the width is much greater than its length. The eighth sternum of’ the female possesses a long seta, and the sternites at the base of the cephalic pair of gonapophyses are small but visible with moderate magnification. The superior anal appendages of the male are much shorter than the inferiors and the parameres of the ninth sternum do not reach the apex. AMPHIAGRION SAUCIUM (Burmeister) — Nymph.—Color, dark brown. Head pentagonal and characterized by having the caudo-lateral angles projecting strongly and forming a short blunt tubercle; an- tennae composed of seven segments, the distal segments being short and similar to those of the nymphs of the genus Argia; labium broad, when folded extending to the metacoxae, the median lobe with three or four mental setae and six lateral setae, and the margins of the median lobe with ten to twelve setae. Thorax brown; legs without brown rings and uniform in color; femora indistinctly carinate; tibiae with rather closely set slender setae; wing-cases extending caudad to the fourth or fifth abdominal segment. Abdomen thickset, the lateral keels absent or feebly developed and without setae; ovipositor of the female nearly reaching the apex of the tenth segment in full-grown nymphs; caudal gills (Fig. 59) transparent, ovate-lanceolate, the apices gradually narrowed to a sharp point ; margins of the gills setose from the proximal to the distal end, the setae placed closely together and increasing in length towards the apices; tracheal trunks sometimes subdividing and forming a number of large branches near the proximal fourth of the gill. Measurements hentethets.-PO soa tee sneer a 11-14 mm. Length of abdomen ............. 7-10 mm. Ienethivob mills 4. seis eskcee tele iar 4.5 mm. Width: obsgille se.jst: amie caemtenes 1.5 mm. 565 Length of metathoracie wing-cases. ..3.5 mm. Length of median lobe......... al: 15 2.0 mm. Width of median lobe ......... 1.25-1.5 mm. Described from a single specimen taken at Muncie, IIl., April 25, 1914, and several specimens obtained from Dr. J. G. Needham, col- lected at Galesburg, Ill., June 3, 1897. Adult; Male.——Color, very dark brown and deep orange-red. Head black or dark above, pale below; labium pale, the median lobe subtriangular, the cleft shallow and broad at the base; antennae dark brown, the first two segments subequal in length, the first with a pale apical ring; postclypeus dark brown; anteclypeus, labrum, ex- posed portions of the mandibles, their trochantins, genae, and a trans- verse stripe on the front above the fronto-clypeal suture, pale buff, the pale area of the front extending dorsad along the margins of the compound eyes to the level of the antennal fossae; remainder of the front and vertex very dark brown, nearly black; occiput and postgenae pale. Thorax dark brown to brick-red and yellowish buff; pronotum dark; proepimera also dark, nearly black; dorsum of the mesothorax, including the supraepisterna and the epimera and the caudo-dorsal angles if the metepisterna, black or dark brown; remainder of the meso- and metathorax yellowish red; intersternum projecting ventrad, conspicuous from the side, and provided with long black setae; legs yellowish buff, the coxae and trochanters yellowish, the femora slightly darker above but without distinct stripes; tibiae entirely pale and the tarsi pale except at the tips; femora with rounded dorsal carinae; wings with ten postnodal cross-veins in the front wing and about eight in the hind wing; M, arising between the fourth and fifth post- nodal cross-veins in the front wing and between the third and fourth in the hind one; stigma reddish, small, surmounting a single cell. Abdomen red and black; terga 1-6 dull red, with the exception of small caudo-lateral black spots on the dorsum of 1-6 inclusive, and subapical spots on five and six; terga 7-10 black on the dorsum, the lateral margins and a broad basal ring on seven reddish; anal appendages (Figs. 174,178) reddish, the superiors shorter than the inferiors, flat and the dorsal surface depressed ; inferiors longer, acute, subconical, the tips directed dorso-mesad ; apical margins of the tenth tergum emarginate on the dorso-meson and depressed at this point, forming a deep rounded pit. Female.—Color in general similar to that of the male but usually considerably lighter, 564 Head similar to that of the male but lighter in color. Thorax buff, and not blackish on the dorsum as in the male; mesostigmal plates as shown in Figure 181. Abdomen: terga 1-4 red; terga 5-7 red with two black spots on each near the caudal fourth; terga eight and nine with two longitudinal black stripes extending from the cephalic margins to within a very ~ short distance of the caudal margins; tergum ten pale buff; sterna 1-10 buff; eighth sternum with a long seta; ovipositor with broad, buff, lateral valves, the ventral margins serrate; prostyles short, brown. Measurements Tuengths sticks ih tats see een 26 mm. en ethin Omir. tyn crate ouiee ee eee ere 26 mm. Length of abdomen, ¢............. 21 mm. Length of abdomen, ¢............. 21 mm. Length of hind wings, ¢............ 16 mm. ‘Length of hind wings, @........... 16 mm. Width) of hind wings; @:...-.....- 3.5 mm. Width of hind wings, 9............ 3.5 mm. Adults have been collected at Urbana during the latter part of May and early part of June, but the species has at no time appeared in great abundance, and attempts to secure the nymphs from this locality have failed. Genus CHROMAGRION Needham The nymphs of this genus are characterized by the projecting caudo-lateral angles of the head and the extremely long and slender gills, which are without conspicuous marginal setae. ‘The median lobe of the mentum is provided with mental setae and the proximal seg- ments of the labial palpi have a single sharp fixed hook and a blunt process with teeth at the apex. The lateral keels are not well developed and are without heavy setae. The adult is characterized by the absence of postocular spots, by the long, somewhat forcipate, anal appendages of the male, and by the peculiar formation of the pronctum of the female—as shown in Figure 170. The parameres of the male extend to the apex of the ninth sternum. The genus is represented in North America by a single species. 565 CHROMAGRION CONDITUM (Hagen) Nymph.—Color, dark brown. Head half as long as wide, the caudo-lateral angles projecting strongly; labium, when folded, extending caudad to the procoxae; mental setae three and sometimes a small fourth; lateral setae five; proximal segment of the palpus with a distinct hook at the apex of the mesal process and the median lobe with a slight notch at the apex. Thorax: femora with two dark rings and a double row of setae on the ventral surfaces; tibiae with a single basal ring of brown; wing-cases reaching caudad to the fifth abdominal segment. Abdomen slender; lateral keels feebly developed and without setae; gills long and slender, widening gradually to near the apices, then suddenly contracted, the margins setose, the setae far apart and increasing in size distad; color of gills uniform dark brown, except that the tips are light; indistinct blotches of darker pigment occur around the margins of the gills; smaller tracheae transparent and indistinct. Measurements STAT De seater es, ercevst Sieve ceeicae on oro érer aia Ave 17 mm. Length of abdomen ............... 10 mm. Menopheonreillsy jc accts cision sas ace: 6 mm. Wad hvotroull iene scrte a ticits tees cere 1 mm. Length of median lobe .............. 2 mm. Width of median lobe .......... .6-1.6 mm. Described from fragments of several exuvia obtained from Dr. J. G. Needham, and the description completed from data given by Needham in his description of the species (’03: 247). Adult; Male.—Color, blue, black, and yellowish orange. Head black and dark brown and buff; mouth-parts yellowish, the labium pale, the median lobe subtriangular in outline, the cleft broad and deep; labial palpi pale, the distal segment also pale ; antennae nearly black, the first segment nearly as long as the second; postclypeus black, the anteclypeus, labrum, mandibles, their trochantins, genae, and the front above the clypeus to the level of the antennal fossae, greenish blue; remainder of the vertex, occiput, and postgenae black. Thorax black and blue, the pronotum largely black, the cephalic lobe, a small spot on the lateral margins of the median lobes, and the lateral margins of the caudal lobe, pale; proepimera and_pro- episterna bluish green, the dorsal borders black; mesostigmal plates long and triangular, the lateral angles pale; mesepisterna with a 566 broad black stripe which, adjoining the wing bases, is exactly the width of the two mesepisterna together, but contracts suddenly shortly cephalad of this, and again about half-way to the cephalic margin of the mesothorax ; mesinfraepisternum with an indefinite black spot on the cephalic border; caudal margins of the mesepimera and metepisterna black, shining, the sclerites themselves pale blue; metepimera lemon- yellow, the cephalic half of the ventral margins frequently dark; post- coxal areas yellowish buff, lateral margins of the intersternum darker ; legs black and greenish buff, the coxae usually black on the cephalic surfaces: trochanters black on the dorsum, the femora with a broad, shining black, dorsal stripe, which encircles the segment at the apex and is narrowed basally on the front femora; femoral setae of the front femora, seven and four in the two rows respectively; tibiae pale buff, with a darker stripe on the ventral surfaces between the rows of setae, the tips dark; tarsi shining black; wings with eleven postnodal cross-veins in the front wing and ten to eleven in the hind one ; stigma surmounting a single cell and much longer than broad. Abdomen blue and black, the first tergum with a short basal black spot on the dorsum and latero-cephalic angles; terga 2-6, in- clusive, blue with cephalo-lateral spots of black; second tergum with an apical shield-shaped spot and an apical ring; terga 3-6 with dorsal longitudinal stripes, narrowed to a line at the cephalic margins and widened to the lateral margins at the caudal end of the segment; terga eight and nine blue, with narrow lateral stripes on the lateral margins and mesal stripes from the base to the distal fourth and small spots on each side of the distal extremity of the lines; tenth segment entirely black except the small blue spots on the dorsum, one on each side of the meson; first sternum pale, with a black median spot, 2-9 black; anal appendages (Figs. 102,106) black, the superior ap- pendages longer than the inferiors, slightly swollen at the apices, and the mesal surfaces densely hairy; inferiors short, pointed at the tip, the dorsal surface flat, the ventral surfaces convex. Female.—Color: the blue of the male is replaced by yellowish buff ; the yellow is the same as that of the male. Head similar to that of the male. Thorax: pronotum curiously modified, the caudal margins of the caudal lobe not continuous (Fig. 170) and the median lobe with a flat lateral projection on each side; proepimera entirely pale; meso- stigmal plates broad, the caudal margins convex, the lateral angles more or less acute, and the latero-caudal margins slightly elevated. Abdomen buff and black, the first tergum with a black basal spot and a cephalo-lateral spot on each side; dorsum of the second tergum 567 with a broad black band from the base to the apex which is widened subapically, and a narrow apical ring; terga 3-7 with small dark spots near the cephalo-lateral angles, broad dorsal longitudinal stripes, nar- rowed at the base but not to a line, and widened at the apex but not reaching the lateral margins of the sclerites except on terga five, six, and seven; terga 7-10 with pale lateral margins and black dorsal stripes, the stripes narrowed at the caudal end; anal appendages of the usual type; ovipositor short, brown, the prostyles short and blunt, the eighth sternites at the base of cephalic pair of gonapophyses. large and subtriangular; sterna 2—7 black, the eighth with a black median line but without an apical spine. Measurements NRCTOU SO 1S ae ol eco re he, «1 loteasisheusit a pyeu? « 35 mm. [Leni Rola ae ie esinins Hanae 36 mm. Length of abdomen, ¢ ............ 29 mm. Length of abdomen, 9............. 30 mm. Length of hind wings, ¢........... 21 mm. Length of hind wings, 2........... 22 mm. Width of hind wines) @ sy .42..o5200% 4 mm. Width of hind wings, 9............ 4 mm. Described from a number of specimens in the collection of Mr. E. B. Williamson, Reported from northern Illinois by Needham (03 : 247). Genus IscHNURA Charpentier The nymphs of this genus have gills with long tapering points and one or more arcuate cross-bands. The labium is moderately broad and the median lobe possesses four or five setae and five or six, usually six, lateral setae. The adults may be distinguished from other genera by the pres- ence of postocular spots, by the origin of vein M., which is between the third and fourth postnodal cross-veins in the front wing and be- tween the second and third in the hind wing, and by the presence in the males of a short apical projection of the dorsum of the tenth tergum, which is, however, not as long as the segment. The sternites at the base of the cephalic pair of gonapophyses of the female are very small and do not project beyond the caudal margin of the large basal sternite of the eighth segment. The parameres of the male do not extend caudad to the margin of the ninth segment and the anal appendages are short, the superiors being about as long as, or shorter than, the inferior appendages. 568 Kry To SPECIES NYMPHS a. Gills with four distinct arcuate cross-bands and a blotch on the tip of the gill; dorsal marginal setae of the median gill extending one- third the length of the gill from the base; lateral setae of the labium, PEVG.g. or alsin abe arte yelazehe an gore gin’ « ouenece sens oy tacrene tate Sa0Ris oR ee a posita. aa. Gills with one or two cross-bands or none, never with four; dorsal marginal setae of the median gill extending one-half the length of the gill from the base; lateral setae of the labium usually six. . verticalis. ADULTS a. Mesopleural pale stripe of the supraepisterna interrupted at the caudal third and forming a distinct exclamation point; eighth sternum of the female!-wath a lone Spine). wc ie sieis cise lave ete aieeaiereiane posita, aa. Mesopleural pale stripe of the supraepisterna not interrupted at the caudal third and not forming a distinct exclamation point; eighth sternum of the female without a long spine. b. Seventh tergum with more or less blue on the dorsum. . . . kellicotti. bb. Seventh tergum black on the dorsum.................-. verticalis. ISCHNURA KELLICoT?TI Williamson Nymph.—Unknown: Adult; Male—Color, blue and black. Head blue and black; labium pale buff, the median lobe subtri- angular; labial palpi broad, the second segment pale; antennae dark brown, with a small pale blue spot on the condyle of the scape; post- clypeus black, anteclypeus blue; labrum blue except a black dorsal marginal line; exposed portions of the mandibles, their trochantins, genae, and the front above the fronto-clypeal suture to the antennal fossae, blue; the blue area of the front is divided by a short black line on the meson and the blue color extends dorsad above the genae to the antennal fossae; remainder of the front and the vertex black; postocular spots large and blue and connected with the blue of the occiput; occiput and postgenae except medium-sized black spots on cach side of the occipital foramen, pale blue. Thorax blue and black; pronotum largely black, the cephalic lobe, caudal margin of the caudal lobe, and four small spots on the median lobe, near the meson, blue; proepimera blue and black, the caudal half being largely blue; mesostigmal plates with blue lateral angles; mesothorax with black supraepisterna which possess narrow longi- tudinal blue stripes, the stripes narrowed conspicuously at the middle 569 and widened at both ends but not extending caudad to the paraptera; dorsal half of the mesepimera black, the black stripe covering that portion suddenly widened by a ventral projection just caudad of the mesinfraepisternum; mesinfraepisterna black except the caudo-ven- tral angles; remainder of the pleura blue, the interpleural fold and the metapleural suture, however, lined with black; postcoxal areas mostly pale; legs blue and black; coxae largely blue, the cephalic sur- faces sometimes spotted with black; trochanters blue, black above; femora with broad dorsal stripes, blue beneath; tibiae, tarsi, and claws brown and without stripes; wings with eight or nine postnodal cross- veins in the front wing and seven in the hind wing; stigma subelliptical, black or blue in the front wing, pale in the hind wing; M, arising between the third and fourth postnodal cross-veins in both wings. Abdomen black, blue, and buff; first tergum blue with the cephalic half black; second, blue with a broad black lateral stripe on each side and a narrow apical ring, the stripes extending from the base of the segment to the caudal third and the two uniting on the meson at the caudal ends; terga 3-6 black, with narrow, blue, interrupted basal ring and lateral marginal stripes; seventh tergum black with pale lateral stripes and a blue apical spot on the dorsum; eighth and ninth terga blue with broad, black, lateral stripes; tenth tergum black, oc- casionally with indefinite blue dorsal spots; anal appendages dark, the superiors broad, laterally compressed and the ventro-mesal angles hook- like; inferiors slightly longer than the superiors, subconical, the tips black; sterna 1-10 black. Female.—Color similar to that of the male. Head similar to that of the male except that the pale area of the front is not divided by the mesal black line. Thorax: the blue of the male is replaced by buff; pale spots of the pronotum large and occupying nearly the whole of it; pale stripe of the mesosupraepisterna extending caudad to the paraptera; legs similar to those of the male, but usually paler in color; stigma of both wings brown. Abdomen: first tergum similar to that of the male; second, blue, with a dorsal black spot near the caudal margin and the lateral mar- gins pale; terga 3-6 black with pale lateral margins; terga 7-10 pale blue with black lateral margins; anal appendages of the usual type; ovipositor with broad lateral styles. Measurements VOCE LDCS On Ga Cee ey ee eae 32 mm. Men othe Qi ppsicnhit sais «heres a ae 31 mm. 570 Length of abdomen, é.............. 25 mm. Length of abdomen, 9............. 25 mm. Length of hind wings, ¢........... 27 mm. Length of hind wings, @........... 28 mm. Width of hind wings, ¢........... 3.5 mm. Wadth or hind iwines.. 9S. ai etree 3.5 mm. This species has not been taken in Illinois, but has been collected in Indiana by Mr. Williamson, and the above description has been made from specimens in his collection. IscHNURA posIta (Hagen) Nymph.—Color, usually dark brown. Head oval or elliptical in outline, the caudo-lateral angles not pro- jecting and with only a few setae; antennae of the usual form, the first two segments dark in color, the second light at the tip; labium extending between or slightly caudad of the procoxae; mental setae four and sometimes a small fifth on each side; lateral setae five; lateral marginal setae of the median lobe four. Thorax about equal in diameter throughout; femora with rows of setae which become heavier towards the apices ; tarsi pale, the apices of the third segments brown; metathoracic wing-cases extending cau- dad to the fourth abdominal segment. Abdomen: cuticle provided with numerous black spots usually hearing a single minute seta; lateral keels without setae except those of the caudal segments; gills lanceolate (Figs. 64, 66), broadest beyond the middle, usually with four crescentic brownish bands of which the apical ones are somewhat paler than the proximal, the median gill with a dorsal row of about fourteen setae extending one-third the length of the gill from the base; ovipositor ene to the apex of the tenth abdominal segment. Measurements encthiz pea setae teeth ee cian 11.5 mm. Length of abdomen................ 7.5 mm Mengthy ol Cillsty eemeracrretai ae 5-5.5 mm Wiadthiter oillss cer cise tsb mice Oia. 1.6 mm. Length of metathoracie wing-cases. .3.0 mm. Length of median lobe............. 2.0 mm. Width of median lobe.......... .O-1.6 mm. The nymph is very closely related to verticalis but may be sep- arated from the latter by means of the shape and figuration of the 571 gills. The lateral setae of the labium do not often exceed five, whereas there are usually six in verticalis. Adult; Male—Color, black and sulphur-yellow. Head black and yellow; mouth-parts buff, the median lobe sub- triangular; palpi narrow, the distal segment pale; antennae uniform dark brown, the second segment considerably longer than the first; postclypeus shining black; anteclypeus pale, labrum pale, with a trans- verse dorsal black stripe which has a slight ventral projection on the meson; remainder of the labrum, exposed portions of the mandibles and their trochantins, genae, and the front dorsad of the fronto-clyp- eal suture to the level of the antennal fossae, shining yellow; re- mainder of the front and vertex black, the postocular spots yellow and circular ; a short yellow line caudad of the ocelli; postgenae and occiput yellow. Thorax black and yellow; pronotum black except the cephalic lobe, which is yellow; caudal lobe with yellow spots on the lateral angles; mesostigmal plates with large oval yellow spots; mesosupra- episterna with short yellow stripes and spots adjacent to the parap- tera, the two together forming an-exclamation point on each side of the dorsal carina; black stripe covering the mesopleural suture on each pleuron contracted near the wing bases; dorsal half of the mes- infraepisterna and a stripe on the metapleural sutures black, the re- mainder of the metathorax and the postcoxal areas yellow; legs black and yellow, the coxae, trochanters, and femora pale, the femora with a dorsal stripe on each from base to apex, the stripe widened subapi- cally ; tibiae with a dorsal black stripe from base to apex which fades into brown towards the apex; tarsi and claws pale, darker at the tips; wings short, the postnodal cross-veins six to eight and M, arising between the third and fourth postnodal cross-veins in the front wing and between the second and third in the hind wing. Abdomen black and yellow; terga 1-10 dull black with the excep- tion of a narrow basal ring on segments 3-7, the stripes narrowed conspicuously on two and widened on the apices of segments 3-6 inclusive; lateral margins of all terga pale yellow; sterna 3-8 lined with black on the meson; apex of the tenth tergum with a mesal eleva- tion at the apex, the elevated portion forming two small tubercles; anal appendages (Figs. 173,177) small, orange, the superiors large and blunt and bent ventrad, the inferiors also large, blunt, and bifur- cate, the arms feebly divaricate and the dorsal arm with a number of heavily chitinized teeth. Female.—Color, pale blue and black. Head similar to that of the male except that the postocular spots are blue. . 572 Thorax pale blue and black, lacking the black stripes on the meta- pleural sutures, and the femoral black stripes almost wanting or re- duced to short subapical lines. Abdomen with the pale and black markings similar to those of the male; anal appendages of the usual type, the ovipositor with pro- styles extending caudad to the apex of the anal appendages. Measurements Meneth waren WAst ti alse. enaletaes 24 mm. Tengetihy ‘Overs: L. Aciseaeta, Selle ieee eee 29 mm. Length of abdomen, .............. 19 mm. Length of abdomen, ?........... 18-22 mm. Length of hind wings, é............ 12 mm. Length of hind wings, ?......... 13-16 mm. Width of hind wings, 3............ 2.5 mm. _ Width of hind wings, @........ 2.0—3.9 Tm. A common species in southern and central Illinois, occurring in the same localities where verticalis is abundant. The adults appear usually somewhat later than verticalis, and the earliest reared speci- mens in my collection bear the date June 12, 1915. Specimens have been seen from Havana, Peoria, and Urbana. ISCHNURA VERTICALIS (Say) Nymph.—Color, pale green, buff, or dark brown. Head broader than long, subelliptical, the caudo-lateral angles with strong setae; antennae with the first two segments and the prox- imal third of three dark, the remainder pale; first two segments sub- equal, the third as long as the first two together; labium, when folded, extending slightly caudad of the procoxae, with four or five mental setae and six lateral setae, the lateral marginal setae of the median lobe six or seven in number. Thorax nearly equal in diameter throughout; front femora with a strong row of setae on the cephalic surface and all the femora with preapical rings of brown; tibiae with several rows of apical setae, two of which extend far proximad; wing-cases extending caudad to the fourth abdominal segment. Abdomen cylindrical and with feeble lateral keels on segments 1-8, the margins and ventral surfaces being thickly studded with short setae; cuticle of the abdomen with small dark spots from which minute setae usually arise, one to each spot; gills (Figs. 62. 65) with long ee ao i ee os 573 tapering points, the dorsal marginal setae of the median gill usually extending nearly half the length of the gill from the base, the ventral row of the same gill consisting of about seven strong setae, consider- ably farther apart than those of the dorsal row; ventral marginal setae of the lateral gills extending slightly farther from the base of the gills than the dorsal row of the median gill; pigment of the gills in the form of one or two arcuate cross-bands near the middle of the gill; these, however, may be wanting; ovipositor extending to the middle of the tenth abdominal sternum. Measurements TCM OANA kes npe.cs o0, k cf xc ove tharetel ones, oes 13-14 mm. Length of abdomen.............. 9-10 mm. WenUN OT US sry cic syat bicleed. wise 6-7 mm. IWiGthmot Cullis se vacrcraccsles e's tie. 1-1.3 mm. Length of median lobe............. 1.8 mm. Width of median lobe.......... .6-1.6 mm. Adult; Male.—Color, black or dark metallic green and pale green. Head black and yellowish green; mouth-parts buff, the median lobe of the labium subtriangular, the cleft short and acute at the prox- imal end; antennae black or very dark brown; postclypeus black, shin- ing; anteclypeus, labrum, exposed portion of the mandibles and their trochantins, genae, and the front above the clypeus, yellow; postocular spots large and subcircular; vertex, and front except the stripe above the clypeus, dull black; occiput black and greenish yellow. Thorax greenish black and greenish yellow; pronotum shining black with a transverse yellow stripe on the cephalic lobe; caudal lobe of the pronotum with a distinct transverse carina ; noto-epimeral suture indistinct, the proepimera and episterna largely yellow; mesothorax shining black with a yellow stripe just above the mesopleural suture; ventral half and cephalic shoulder, of the mesepimera yellow; paraptera trapezoidal, with a yellow spot just ventrad of the lateral angles, the remainder black; mesostigmal plates black, the caudal margins ele- vated and lined with yellow; metathorax including the postcoxal areas, pale green or yellowish; legs black and yellow, the coxae and tro- chanters pale with some darker marks on the sutures; femora all with a broad dorsal stripe, the tibiae with narrower dorsal stripes extending from near the bases to near the apices; tarsi and claws pale, dark at the tips; wings short, the postnodal cross-veins seven to nine, and M, arising between the third and fourth postnodal cross-veins in the front wing and between the second and third in the hind wing. 574 Abdomen shining black or green, and yellowish green; dorsum- of terga 1-7, inclusive, shining black or green with narrow apical ring on the first, interrupted basal rings on 3-6, and the lateral margins of 1-6 yellow; dorsum of terga eight and nine blue, with short lateral black stripes on each side about half the length of the segment; tergum ten black, the lateral margins pale, the caudal margin with a short forked process on the meson; sterna 3-9 with a mesal line of black; . anal appendages (Fig. 168) short, the superiors flat and placed nearly vertically ; inferiors longer, and with a dorsal, basal knob and a larger, subconical ventral lobe. Female.—Color, orange and black or entirely black. Head similar to that of the male except that the yellowish green markings are replaced with orange. Thorax orange and black; pronotum with an orange spot on each median lobe; margin of the caudal lobe with orange spots ; mesostigmal plates (Fig. 180) with caudal elevated margins orange in color ; meso- pleural pale stripe of the supraepisterna orange and much broader than the pale stripe of the male; dorsal third and caudal margin of the mesinfraepisterna black, the remainder pale orange; metathorax orange; legs orange and black, the femora entirely pale except at the tips, the tibiae with the usual dorsal stripes. Abdomen orange and black, the first two segments entirely pale except a narrow ring on the caudal margin of the second; terga three orange with an apical spot and ring; dorsum of terga 4-8 black, with pale basal rings on 4-6 and the apical third of eight also pale; terga nine and ten indefinitely marked with black, there being an orange spot and apical ring of orange on nine and a dorso-mesal line on the same; lateral margins of all the terga orange; sterna 1-8, inclusive, with a mesal black line, the eighth sternum with a heavy spine; anal appendages of the usual type; the ovipositor with dark brown pro- styles and pale lateral valves. In older specimens the orange color becomes black and pollinose so that it is difficult to distinguish the species on the wing from some of the Enallagmas which also have a tendency to become dark. Measurements Meri ethy nieces, obevanuelareveicieeve: sve ortie ere 20 mm Toeneth) 945 cisle tate cee nea sere 30 mm. Length of abdomen, ¢.......... 2.22) 00m, Length of abdomen, ?.......... 23-24 mm. Length of hind wings, ¢........... 14 mm. Length of hind wings, 9........... 17 mm. Width of hind wings, ¢........... 3.5 mm. Width of hind wings, °........... 3.5 mm. 575 The commonest species in Illinois, occurring practically where- ever there is enough permanent water for the nymphs to live. The adults appear early in May and continue to emerge until September and possibly later. Specimens have been seen from Dubois, Carbondale, Golconda, Havana, Lake Villa, Mahomet, Muncie, Peoria, Urbana, and Vienna. Genus ANOMALAGRION Selys The nymphs of this genus are characterized by their unusually small size, by the presence of a very slender tip to the gills, and by the absence of setae on the lateral keels. The male adults are unique in having the stigma of the front wing removed from the margin and in the possession of a long process on the dorsum of segment ten. The sternites at the base of the cephalic pair of gonapophyses of the female are wanting, and the parameres of the ninth sternum of the male do not reach the apex of the segment. ANOMALAGRION HASTATUM (Say) Nymph.—Color, green or buff. Head with the caudo-lateral angles rounded and without setae; antennae with the first two segments dark brown, the remaining ones light in color; second segment about as long as the first or slightly longer; labium not extending caudad of the procoxae and about as broad as long; mental setae four, lateral setae five. Thorax narrower than the head; legs without dark rings and with few setae, the tibiae with the usual apical scales; wing-cases extending nearly to the fourth abdominal segment. Abdomen uniform in color; lateral keels feebly developed and without setae; gills (Fig. 60) lanceolate, with a long point; marginal setae of the median gill consisting of a thick dorsal row, extending about one-third the length of the gill from the base, and a scattered ventral row at the base; ventral marginal row of setae of the lateral gills slightly longer than the dorsal row of the median gill; ovipositor extending to the caudal margin of the tenth abdominal sternum. Measurements Rem ati prmiaitsicccayare!stenre chavs teraia Si 9.5 mm. Bengethy of abdomen. ssi c.cl «s erevere sc 5.5 mm. Wenmoth Ofer Gilisy cies). sysir ester ote 4.5 mm. WiTGGH Of Polls 4s aele ccete alse a ote os 1.0 mm. Length of median lobe............. 1.6 mm. Width of median lobe.......... 0.5-2.0 mm. 576 Adult; Male.—Color, pale lemon-yellow and black. Head lemon-yellow and metallic black; mouth-parts buff, the median lobe with a wide cleft which is obtuse at the proximal end; antennae dark brown except the proximal segment, which has a pale stripe from the base to the apex ; postclypeus shining black ; anteclypeus pale; labrum with a transverse black stripe on the dorsal margin, the remainder yellow ; exposed portions of the mandibles, their trochantins, the genae, and the front above the fronto-clypeal suture to the antennal fossae, yellow; remainder of the front and the vertex metallic bronze with the exception of very small postocular spots, a small yellow spot ventrad of the median ocellus, and a narrow yellow stripe caudad of the ocellar area. Thorax greenish yellow and metallic black; cephalic lobe of the pronotum with a yellow transverse stripe; median lobes metallic black; caudal lobe black with three short marginal dashes; noto-epimeral suture indistinct; dorsal carina of the mesothorax feebly developed, the mesothorax largely black with a narrow yellow line just dorsad of the mesopleural suture ; dorsal half of the mesosupraepisterna black; metepisterna and epimera yellow or buff; paraptera trapezoidal, the cephalic margins with a pale line; coxae pale yellow, the femora pale, with dorsal black stripes widened distad; tibiae pale, with short, prox- imal, dorsal and ventral dark stripes, the tarsi and claws pale except at the tips; setae of the front femora few, about three in each row, the distance between them much greater than their length; wings (Figs. 82, 83) very short; postnodal cross-veins six in the front wing and five in the hind; M, arising near the third postnodal vein in the front wing and between the second and third in the hind wing; stigma of the front wing ovoid, remote from the margin, the stigma of the hind wing rhomboidal and in contact with the margin of the wing. Abdomen yellow and orange, the black confined to longitudinal dorsal bands on terga 1-3 and six, the stripe on three and the one on six being conspicuously widened subapically; basal and apical black spots present on the fourth and fifth terga, and a dorsal stripe on seven which is about three-fourths the length of the segment; the narrow basal ring on segments I—7 is interrupted on the meson in all except the first; tenth tergum with a dorsal process about as long as the segment and bifurcate at the apex; anal appendages (Figs. 166, 167) small, the superiors bifurcate, and with a broad mesal lobe extending caudo-ventrad and a conical lateral one projecting caudad; inferiors conical, slightly longer than the superiors. 577 Female.—Color, orange and black or dark brown. Head orange and black, differing from that of the male in having the black of the postclypeus reduced to a dorsal line and that of the labrum to lateral spots; postocular spots wanting, the caudal margins of the head with a broad orange stripe; occiput and postgenae pale. Thorax: prothorax as in the male except that the black of the pronotum does not extend as far onto the lateral aspect; dorsal black stripe of the mesothorax extending on each side of the dorsal carina one-half the width of the supraepisterna; mesopleural suture with a black line, the remainder of the thorax orange and buff; mesostigmal plates as shown in Figure 164. Abdomen orange, with narrow basal black rings on terga 2-4 inclusive, a longitudinal dark stripe on the caudal three-fourths of five, similar stripes extending the full length of six, seven, and eight, and two triangular spots at the base of the ninth; dorsum of the tenth tergum with a short blunt projection; anal appendages short; ovipositor long and extending caudad of the anal appendages; prostyles short and blunt. Measurements Length, d....... RT Ras cee 23 mm. JU(SovetHat, Plu Reem a rere Be ci re ee ea 24.5 mm. Length of abdomen, ¢............. 17 mm. Length of abdomen, ?............. 19 mm. Length of hind wings, ¢.........10.5 mm. Length of hind wings, @........... 14 mm. Width of hind wings, ¢........... 1 mm. Width of hind wings, 2......... 2-2.5 mm. This species is rather more common in the southern half of the state than in the northern. It appears on the wing as early as June 20 at Urbana, but has been taken at Carmi, June 14, 1915. BIBLIOGRAPHY The following bibliography has been made as complete as possible in literature dealing with the nymphs. The remaining portion is in- tended to include the works referred to in the preceding pages and also the more important systematic publications, such as monographs and catalogues. To persons beginning a study of the Odonata, Mutt- kowski’s “Catalogue of the Odonata of North America” and Calvert’s “Progress in our Knowledge of the Odonata from 1895 to 1912” should be considered indispensable. In these two works, most of the literature appearing previous to 1912 is cited. A number of important 578 articles have appeared since that date, and an attempt has also been made to include these in this bibliography. NYMPHS Backhoff, Paul 10. Die Entwicklung des Copulationsapparates von Agrion. Ein Beitrag zur postembryonalen Entwicklungsgeschichte der Odo- naten. Zeit. wiss. Zool., 95: 647-706, pl. 21. Balfour-Browne, F. ‘og. Life-history of the agrionid dragonfly. Proc. Zool. Soc. Lon- don, 1909: 253-285, pls. 23, 24. Bervoets, R. 13. Sur le systeme trachéen des larves d’Odonates. Ann. Biol. Lacustre, 6: 15-32, figs. 1-3. Borner, C. ‘09. Neue Homologien zwischen Crustaceen und Hexapoden. Die Beissmandibel der Insekten und ihre phylogenetische Bedeu- tung. Archi- und Metapterygota. Zool. Anz., 34: 100-125. Brimley, C. S. ‘04. Note on duration of larval stage of Odonata. Ent. News, 15: 136. : Butler, Hortense . 04. The labium of the Odonata. Trans. Am. Ent. Soc., 30: 111- 134, pls. 2-7. Calvert, PB. P. ‘oo. Moults in the Odonata. Entomologist, 33: 350. ‘Ir. Studies on Costa Rican Odonata. Ent. News, 22: 49-64, pls. 2, 3. 15. Studies on Costa Rican Odonata. Ent. News, 26: 385-395, pls. 15-17. Forbes, S. A. 88. On the food relations of fresh-water fishes. Bull. Ill. State Lab. Nat. Hist., 2: 485. Gilson, G., and Sadones, J. 96. Larval gills of Odonata. Trans. Linn. Soc. London, 25: 413. Hagen, H. 80. Essai d’un synopsis des larves des Caloptérygines. Ann. de la Soc. Ent. de Belgique, 23: LXV-LXVII. 2. 579 Heymons, R. 96. Grundziige der Entwickelung und des Korperbaues von Odo- naten und Ephemeriden. Anhang zu den Abhandl. Konigl. Preuss. Akad. Wiss. Berlin, 1896. 66 pp., pls. 1, 2. 704. Die Hinterleibsanhange der Libellen und ihrer Larven. Ann. k.k Naturhist. Hofmus., 19: 21-58, pl. 1. Kennedy, C. H. 15. Notes on the life history and ecology of dragonflies (Odo- nata) of Washington and Oregon. Proc. U. S. Nat. Mus., 49: 259-345. Lucas, W. J. 12. Early stages of British Odonata. Rep. Lancash. Ent. Soc., 35: 17-24. Lyon, Mary B. 15. The ecology of the dragon-fly nymphs of Cascadilla Creek. Ent. News, 26: 1-15,*pl. 1. Needham, J. G. 03. Life histories of Odonata, suborder Zygoptera. Damsel’ flies. Bull. N. Y. State Mus., 68: 218-279, pls. 11-19. 11. Descriptions of dragonfly nymphs of the subfamily Calop- teryginae. Ent. News, 22: 145-154, pls. 4, 5. "11a. Notes ona few nymphs of Agrioninae (order Odonata) of the Hagen collection. Ent. News, 22: 342-345, pl. 11. Pierre, l’Abbé ‘04. Sur l’éclosion des ceufs de Lestes viridis. Ann. Soc. Ent. France, 73: 477-484, pl. 4 Riley, Cane Cc "12. Observations on the ecology of dragon-fly nymphs: reactions to light and contact. Ann. Ent. Soc. “Amer., 5: 273-202. Ris, F. og. Odonata. Die Siisswasserfauna Deutschlands, Heft 9. ’ Rousseau, E. ‘og. Etude monographique des larves des Odonates d’Europe. 5 Ann. Biol. Lacustre, 3 : 300-366, figs. 1-47. Sadones, J. 95. L/’appareil digestif et respiratoire larvaire des Odonates. La Cellule, 11 : 273-324, pls. 1-3. 580 Tillyard, R. J. ‘06. Life history of Lestes leda Selys. Proc. Linn. Soc. N. S. Wales, 31 : 409-423, pls. 32, 33. ‘tr. On the genus Cordulephya. Proc. Linn. Soc. N. S. Wales, 36: 388-422, pls. 11, 12. *12. Onthe genus Diphlebia, with descriptions of new species and life histories. Proc. Linn. Soc. N. S. Wales, 36: 584-604, pls. 19-20. Van der Weele, H. W. ‘06. Morphologie und Entwicklung der Gonapophysen der Odo- naten. ‘Tijdschr. v. Ent., 49: 99-198, pls. 6-8. Walker, E. M. 13. New nymphs of Canadian Odonata. Can. Ent., 45: 161-170, Diswsliene: Ld: The known nymphs of the Canadian species of Lestes. Can. Ent., 46: 189-200, pls. 13, 14. I4a. New and little-known nymphs of Canadian Odonata. Can. Ent., 46: 349-357, 370-377, pls. 23, 25- Warren, A. 15. A study of the food habits of the Hawaiian dragonflies or pinau. College of Hawaii Publications, Bull. 3, pls. 1-4. Wesenburg-Lund, C. 13. Odonaten-Studien. International Revue, 6: 155-228, 373- 422. ’ ADULTS Banks, N. ‘92. A synopsis, catalogue, and bibliography of the neuropteroid insects of temperate “North America. Trans. Am. Ent. Soc., 19: 327-373- Brandt, A. 69. Beitrage zur Ey iaielealentase oe cee der Libelluliden und Hemipteren, mit besonderen Beriicksichtigung der Libelluliden. Mém. Acad. Imp. des Sci. St. Pétersb., ser. 7, 13: 1-33, pls. 1-3. Brauer, F. 68. Verzeichniss der bis jetzt bekannten Neuropteren im Sinne Linné’s. Verhandl. d. k.-k. zool.-bot. Gesell. Wien, 18: 359- 416, 711-742. ,. eee wed oe ee 581 @alvert, 2: P: ‘93. Catalogue of the Odonata (dragonflies) of the vicinity of Philadelphia, with an introduction to the study of this group of insects. Trans. Am. Ent. Soc., 20: 152a-152d; 153-272, pls. 242: ‘08. The composition and ecological relations of the odonate fauna of Mexico and Central America. Proc. Acad. Nat. Sci. Phila., 60 : 460-491. ‘o8a. Odonata. Biol. Centr.-Amer., Neuroptera, pp. V-X XX, 17- 410, pls. 2-10. "12. Progress in our knowledge of the Odonata from 1895-1912. Trans. Sec. Intern’t’l Congr. of Ent., pp. 140-157. 13. The species of Nehalennia (Odonata). Ent. News, 24: 310- 316. ; "13a. The fossil odonate Phenacolestes, with a discussion of the venation of the legion Podagrion Selys. Proc. Acad. Nat. Sci. Phila., 65 : 225-272, pl. 14. Calvert, P. P., and Hagen, H. A. ’o2. (See Hagen and Calvert) Hagen, H. 4 ‘61. Synopsis of the Neuroptera of North America, Smithsonian Miscellaneous Collections, 1861 : 55-187. *75. Synopsis of the Odonata of North America. Proc. Bost. Soc. Nat. Hist., 18: 20-96. Hagen, H. A., and Calvert, P. P. ’o2. Illustrations of Odonata: Argia, witha list and bibliography of the species. Bull. Mus. Comp. Zool., 39, No. 4: 103-120, pls. 1, 2. Handlirsch, A. 0608. Die Fossilen Insekten. 1430 pp., 51 pls. Leipzig. "11. New Paleozoic insects from the vicinity of Mazon Creek, Illinois. Am. Jour. Sci., ser. 4, 31 : 297-326. Kellicott, D. S. 99. The Odonata of Ohio. Ohio State Acad. Sci., Special Pa- pers, No. 2. 114 pp., figs. 1-39. Kennedy, C. H. ’o2. A list of the dragonflies of Winona Lake. Proc. Ind. Acad. Sci., 1902 : 159-164. ’o2za. A new diagnostic character for the species of the genus Argia. Proc. Ind. Acad. Sci., 1902: 164-169, pls. 1, 2. 582 Kirby, W. F. ‘90. Synonymic catalogue of Neuroptera Odonata, or dragonflies, with an appendix of fossil species. 202 pp. London and Berlin. Tyucas; Ws |: ‘oo. British dragonflies (Odonata). 356 pp., 27 pls. London. Marshall, W. S. ‘14. On the anatomy of the dragonfly, Libellula quadrimaculata Linné. Trans. Wis. Acad. Sci., Arts, and Letters, 17, Pt. 2: 755-786, pls. 69, 70. Morgan, Anna H. 13. A contribution to the biology of the May-flies. Ann. Ent. Soc. Amer., 6: 371-413, pls. 42-54. Muttkowski, R. A. 7o8. Review of the dragon-flies of Wisconsin. Bull. Wis. Nat. Hist. Soc., n. s., 6: 57-123, pls. 4-6. “iO} Catalogue of the Odonata of North America. Bull. Pub. Mus. City of Milwaukee, Vol. 1, Art. 1. 207 pp. Needham, J. G. 03. A genealogic study of dragon- fly wing venation. Proc. U. S. Nat. Mus., 26: 703-764, pls. 31-54. Packard, A. S. 68. On the development of a dragon-fly (Diplax). Proc. Bost. Soc. Nat. Hist., 11: 365-372. Poulton, E. B. ‘06. Predaceous insects and their prey. Trans. Ent. Soc. London, 1906 : 323-409. Ridgway, R. "12. Color standards and color nomenclature. 43 pp., 53 pls. Washington. Risse ’96. Untersuchung itber die Gestalt des Kaumagens bei den Libel- len und ihren larven. Zool. Jahrb., Abt. Syst. Geogr. u. Biol. Thiere, 9: 396-624. Scudder, S. H. ‘90. The tertiary insects of North America. Rep. U. S. Geol. Surv. Terr., XIII. 663 pp., 28 pls. : Sellards, E. H. 06. Types of Permian insects. Am. Jour. Sci., ser. 4, 22: 249- 258. 583 Selys-Longchamps, aoe de 62. Agrionines. 2"° Légion.—Lestes. Bull. de l’Acad. Roy. des Sci., des aia et des Beaux-Arts de Belgique, sér. 2, 13: 291-338. ‘65. Synopsis des Agrionines—[Argia]. Idem, 20: 375-417. ’76. Synopsis des Agrionines. Le grande genre Agrion. Idem, 41: 247-322, 496-539, 1233-1309; 42: 490-531, 952-991. Selys-Longchamps, Edm. de, and Hagen, H. A. 54. Monographie des Caloptérygines. 291 pp., 14 pls. Snodgrass, R. E. ‘og. The thorax of insects and the articulation of the wings. Proc. U.S. Nat. Mus., 36: 511-595, pls. 40-69. Thompson, O. S. 08. Appendages of the second abdominal segment of male dragon flies (order Odonata). Bull. N. Y. State Mus., 124: 249-263, figs. 17—28. Walsh, B. D. 62. List of the Pseudoneuroptera of Illinois contained in the ae inet of the writer, with descriptions of over 40 new species, and notes on their structural affinities. Proc. Acad. Nat. Sci. Phila., 1862: 361-401. Williamson, E. B. ‘oo. The dragonflies of Indiana. Dept. Geol. and Nat. Resources, Ind., Rep. 24: 233-333, pls. 1-7. "00a. Notes on a few Wyoming dragonflies. Ent. News, 11: 453-458, pl. 9. 12. Hetaerina titia and tricolor (dragonflies-Odonata). Ent. News, 23: 98-101. ‘12a. The dragonfly Argia mocsta and a new species (Odonata). Ent. News, 23: 196-203. Wilson, C. B. ‘og. Dragonflies of the Mississippi valley collected during the pear’ mussel investigations on the Mississippi River, July and August. 1907. Proc. U.S. Nat. Mus., 36: 653-671. 584 INDEX TO GENERA AND SPECIES Aeshna, 463. Agrion, 412, 417, 421, 442, 465, 466, 472. aequabile, 465, 467-469. yakima, 438, 467. maculatum, 438, 465, 467, 468, 469— 471. virgo, 439. Amphiagrion, 465, 499, 500, 562. saucium, 465, 562-564, Anax junius, 412. Anomalagrion, 465, 500, 501, 575. hastatum, 465, 575-577. Argia, 417, 421, 430, 444, 465, 499, 500, 501, 562. apicalis, 445, 465, 502, 503-506, 507, 512, 514. fumipennis, 465, 502, 503, 506-507. moesta putrida, 438, 465, 501, 502, 503, 507-510. putrida, 440. sedula, 465, 502, 503, 510-511. tibialis, 440, 465, 502, 503, 511-514. violacea, 465, 502, 503, 515-517. Calopteryx, 413, 442. virgo, 439. Chromagrion, 427, 465, 499, 500, 564. conditum, 465, 565-567. Cora, 451, 457. Enallagma, 423, 465, 500, 501, 517. antennatum, 438, 445, 465, 518, 520, 521-524, aspersum, 465, 519, 520, 524-525. ealverti, 465, 476, 500, 518, 520, 521, 525-528, 536. earunculatum, 442, 465, 476, 518, 519, 520, 527, 528-531, 532, 533, 534, 539, 540, 550. civile, 445, 465, 476, 518, 519, 521, 527, 528, 531-534, 539, 540, 550. Enallagma—continued. eyathigerum, 465, 500, 518, 520, 521, 528, 534-536, divagans, 465, 476, 520, 521, 536—- 538. doubledayi, 465, 476, 519, 521, 528, 538-540. : ebrium, 465, 520, 540-541, exsulans, 442, 465, 518, 520, 521, 522, 524, 538, 542-544, 559. geminatum, 442, 465, 517, 519, 520, 544-547. hageni, 439, 445, 465, 517, 520, 534, 547-550. piseinarium, 465. pollutum, 465, 518, 519, 521, 550- 553. pulchellum, 439. signatum, 438, 443, 465, 518, 519, 521, 544, 553-556. traviatum, 465, 518, 519, 521, 556— 559. : Buphea, 457. Gomphus, 430, 463. Hetaerina, 417, 426, 434, 435, 444, 465, 466, 467, 471. americana, 445, 465, 471-474, 475. titia, 465, 471, 474-476. tricolor, 476. Tschnura, 435, 465, 500, 501, 567. elegans, 439. kellicotti, 465, 568-570. posita, 465, 568, 570-572. verticalis, 423, 438, 439, 440, 442, 443, 445, 465, 555, 568, 570, 571, 572-575. Lestes, 418, 421, 422, 427, 430, 435, 438, 439, 440, 442, 444, 451, 465, 477, 485, 492. congener, 465, 477, 478, 479-482. Lestes—continued. disjunctus, 465, 476, 478, 479, 481, 482-483, 485, 487. eurinus, 465, 478, 479, 483-485. forcipatus, 465, 476, 478, 479, 483, 485-487, 490, 492, 494, 496. inaequalis, 465, 478, 479, 485, 487-— 489. rectangularis, 443, 465, 478, 479, 483, 487, 489-492, 494, 496. ou uneatus, 465, 477, 478, 479, 492- 494, 496. unguiculatus, 465, 478, 479, 492, 494-496, vigilax, 445, 465, 478, 479, 485, 489, 496-499. Nehalennia, 427, 465, 499, 500, 559. irene, 465, 559-561. Sympetrum striolatum, 439. 586 ABBREVIATIONS A, anal vein A,-A,,, abdominal segments 1-11 aai, anal appendages of adult—inferior aas, anal appendages of adult—superior ag, accessory genitalia of male ane, antenodal cross-veins ant, antennae are, areulus awp, anterior wing-process br, bridge bsp, basilar space Cs costa ed, eardo ce, compound eyes ei, eerecl el, eardella ely, elypeus er, chitinous rod of the submentum Cu,, Cu,,eubitus—branches of ew, claws ex, coxa exp, coxal process de, dorsal carina epes, epicranial furrow epm, epimeron fi front fe, femur fi, fureal invaginations fl, furcella fs, femoral setae g, gills—caudal ga, galea gb, genital lobe gd, gills—dorsal gle, galea-lacinia en, genae hm, hamules ; hp, hypopharynx ieps, infraepisternum insu interpleural suture ints, intersternum lb, labium lbr, labrum le, lacinia Ik, lateral keel Ip, labial palpus Ip, lp., labial palpus—first and second seg- ments ls, lateral setae of labial palpus M, media M,,—M,, media, branches of the mapl, metapostseutellum masl, me, mep, md, me, mfi, min, ml, mopl, mosl, mp, mpf, mph, mpp, ms, msec, msel, mse, msp, mssu, mst, mstg, mstm, msty, mtep, mtfi, mtn, mtpf, mtse, mtsl, mtsm, mtst, mtsu, mx, USED IN LETTERING PLATES metaseutellum median cleft of the labium mesocoxal process mandible mentum mesofureal invaginations microthorax, epimeron of the median lobe of the labium mesopostscutellum mesoscutellum metaphragma mesoprefurcal invaginations mesophragma mesophragmal invaginations mental setae mesoscutum—caudal portion mesoprescutum—cephalie portion of mesoscutum marginal setae of the median lobe mesothoracie spiracle mesopleural suture mesosternum mesostigmal plates (caudal) mesosternellum mesostigmal plates (ventral) metacoxal process metafureal invaginations metanotum metaprefurea metaseutum metathoracie spiracle metasternellum metasternum metapleural suture maxilla maxillary palpus nodus ocelli caudal valves or gonapophyses cephalic valves or gonapophyses occipital ridge oceiput paraptera parameres pronotum—caudal lobe pronotum—cephalie lobe procoxal process proepimeron proepisternum postgena palpiger pronotum—median lobe i) A OB Co Puate LVIII Nymphal Structures . Enallagmea sp., cross-section of the head through the hypopharynx and maxillae. Enallagma sp., cross-section of the head eaudad of the section shown in Figure 1. Enallagma sp., cross-section through the labium. Enallagma sp., longitudinal section of the head. Lestes forcipatus, anal segments and bases of gills. Enallagma sp., cross-section of labium near hinge. Enallagmwa exsulans, ventral aspect of the head with the labium folded back and the remaining mouth- parts in position. . Agrion maculatwm, labium. . Hetacrina americana, labium. . Lestes forcipatus, labium. Argia violacea, labiam. . Ischnura verticalis, labium. Enallagma carunculatum, labium. Se, pronotum postnodal eross-veins propleural suture prostyles presternum penis metapreseutum prosternellum mesopresternum pretarsus posterior wing-process quadrangle radius—first branch radial sector subeosta Se,, Se., subeosta, branches of _seps, supraepisternum | submentum _ Spring-vein stigma sternites (caudal) of the ee abdominal segment stipes seminal vesicle tentorium tarsus tibia tibial comb trochantin of mandible trochanter tibial setae vertex wing-case wing process a PLate LVIII GaN wh on Meet Se Wipe | Mi Tt Fig. Fie. Fig. Fig. Fig. Fie. Fie. Fig. Fig. Fig. Fie. Fig. Fig. Piare LIX Nymphal Structures Lestes rectangularis, wing-case. Hetaerina americana, wing-ease. Enallagma signatum, wing-case. The same, young nymph, wing-case. . Ischnura verticalis, caudal end of the abdomen with the two lateral gills removed. Enallagma exsulans, tarsus. The same, leg. Tschnura verticalis, dorsum of meso- and metathorax. Agrion maculatum, maxilla. Hetaerina americana, dorsum of the prothorax. Ischnura verticalis, ventral aspect of thorax and cephalic segments of abdomen. The same, lateral aspect of thorax and ab- domen. Enallagma sp., cross-section of gills. IDIPAt mr aT 10x. Puate LX Nymphal and Adult Structures . Ischnura verticalis, adult, ventral aspect of pro- thorax. The same, adult, maxilla. . Hetaerina americana, adult, ventral aspect of pro- thorax. . Ischnura verticalis, adult, caudal aspeet of head. 31. Plecoptera nymph, maxilla. 2. Ischnura verticalis, adult, cephalic aspect of head. Hetaerina americana, adult, ventral view of the second abdominal segment of the male. The same, adult, anal appendages, dorsal view. . Ischnura verticalis, adult, leg. . The same, adult, lateral view of PEqrhoray The same, adult, labium. . Hetaerina americana, adult, lateral view of anal appendages. The same, adult, lateral view of prothorax. IPE ILD Puate LXI Thoracic Structures of Adults . Hetaerina americana, ventral aspect of the meso- and meta- thorax. ; Hetaerina titia, dorsal aspect of meso- and metathorax. Tschnura verticalis, ventral aspect of meso- and metathorax. The same, lateral aspect of meso- and metathorax. The same, dorsal aspect of meso- and metathorax. Hetaerina americana, lateral aspeet of meso- and meta- thorax. The same, dorsal view of meso- and metaterga. Tschnura verticalis, dorsal view of meso- and metaterga. PLate LXI Puate LXIT Caudal Gills of Nymphs* 48. Lestes vigilax. Fig. 53. .49. Lestes forcipatus. Fig. 54. .50. Lestes congener. Fig. 55. 7.51. Lestes unguiculatus, Fig. 56. normal gills. Fig. 57. @.52. The same, dark gills. *One of the lateral gills removed in most cases. Enallagma exsulans. Enallagma antennatum., Enallagma traviatum. Enallagma signatum. Enallagma pollutum. Pirate LXII Puare LXITI Caudal Gills of Nymphs* Fig. 58. Argia moesta putrida. Fig. 65. Ischnura verticalis, Fig. 59. Amphiagrion saucium. young nymph. Fig. 60. Anomalagrion hastatum. Fig. 66. Ischnura posita. Fig. 61. Nehalennia irene. Fig. 67. Argia apicalis. Fig. 62. Ischnura verticalis. Fig. 68. Argia tibialis. Fig. 63. Argia violacea. Fig. 69. Enallagma signutum, Fig. 64. Ischnura posita. variations in pig- mentation. *One of the lateral gills removed in cases where the gills are attached to the abdomen. BEATE Ie ennT PuateE LXIV Caudal Gills of Nymphs* and Wings of Adults Fig. 70. Enallagma carunculatum, Fig. 76. Enallagma hageni, gills. gills. Fig. 77. Hnallagma exsulans, dark Fig. 71. Enallagma cyathigerum, and light gills. gills. Fig. 77a. The same, abnormal gills. Fig. 72. Enallagma geminatum, Fig. 78. Hetaerina americana, gills. male, wings. Fig. 73. Agrion aequabile, wings. Fig. 79. The same, nymphal skin. Fig. 74. Hetaerina americana, Fig. 80. Enallagma (?) calverti, wings. lateral gill. Fig. 75. Enallagma civile, gills. *One of the lateral gills removed in cases where the gills are attached to the abdomen. Prats LXIV Fig. Fig. Fig. Fig. Fig. Puate LXV Wings of Adults . Ischnura verticalis. Anomalagrion hastatum, female. The same, male. Chromagrion conditum. . Lestes rectangularis. Fig Fig Fig Fig . 86. eels . 88. . 89. . 90. Ischnura posita. Enallagma hageni. Nehalennia irene. Amphiagrion saucium. Argia apicalis. PLATE LXV ———— Jue = wes ——__——5 _——— Fig. 103. Fig. 104. Fig. 105. Fie. 106, Fie. 107. Fie. 108. PuatE LXVI Abdominal Structures of Adults Enallagma carwnculatum, female, dorsal view of abdomen. Enallagma civile, female, dorsal view of abdomen. Enallagma cyathigerum, female, dorsal view of abdomen. Enallagma traviatum, female, dorsal view of abdomen. Enallagma aspersum, female, dorsal view of abdomen. Enallagma geminatum, female, dorsal view of abdomen. Enallagma carunculatwm, male, penis. Enallagma cyathigerum, male, penis. Enallagma carunculatum, female, caudal abdominal segments. Anomalagrion hastatum, female, caudal abdominal segments. Enallagma hageni, male, penis. Chromagrion conditum, male, anal appendages. Enallagma civile, male, anal appendages. Ischnura verticalis, female, caudal abdominal segments. Enallagma civile, male, penis. Chromagrion conditum, male anal appendages. Enallagma ebrium, male, penis. Enallagma calverti, male, penis. 109. 110. Matis mio s113: Mig. 114, 115. . 116. mnie SAS: rt: . 120. GAIPALe . 122. Puate LXVII Abdominal Structures of Adults Agrion maculatum, female, caudal end of abdomen. Agrion aequabile, female, caudal end of abdomen. Hetaerina titia, female, caudal end of abdomen. Hetaerina americana, female, caudal end of abdomen. Lestes uncatus, female, caudal end of abdomen. Lestes forcipatus, female, caudal end of abdomen. Lestes rectangularis, female, caudal end of abdomen. Argia moesta putrida, female, caudal end of abdomen. Agrion aequabile, male, anal appendages. The same, male, sternum of the ninth segment. Hetaerina titia, male, anal appendages. Lestes disjunctus, male, second abdominal segment, from side. Hetaerina americana, male, sternum of the ninth seg- ment. Lestes forcipatus, male, second abdominal segment, lateral view. Pirate LXVII Puate LXVIII Anal Appendages of Adults Fig. 123. Lesles congener. Fig. 132. Lestes inaequalis. Fig. 124. Lestes congener. Fig. 133. Lestes disjunctus. Fig. 125. Lestes wnguwiculatus. Fig, 134. Agrion aequabile. Fig. 126. Lestes ungwiculatus. Fig. 135. Lestes wneatus. Fig. 127. Lestes rectangularis. Fig. 136. Lestes wneatus. Fig. 128. Lestes rectangularis. Fig. 137. Lestes forcipatus. Fig. 129. Lestes vigilaz. Fig. 138. Lestes forcipatus. Fig. 130. Lestes vigilax. Fig. 139. Agrion maculatum. Fig. 131. Lestes inaequalis. Fig. 139a. Agrion maculatum. Pirate LXVIII Puate LXIX Thoracic and Abdominal Structures of Adults r. 140. 141. g. 142. . 143. ig. 144. . 145. . 146. . 147. . 148. . 149. . 150. Argia tibialis, female, mesostigmal plates. Argia sedula, female, mesostigmal plates. Argia violacea, female, mesostigmal plates. Argia fumipennis, male, anal appendages. The same, male, anal appendages. Argia violacea, male, anal appendages. The same, male, anal appendages. Argia apicalis, male, ninth sternum. Argia fumipennis, female, mesostigmal plates. Argia sedula, male, anal appendages. The same, male, anal appendages. Argia apicalis, male, anal appendages. The same, male, anal appendages. The same, female, mesostigmal plates. Argia moesta putrida, female, mesostigmal plates. Argia tibialis, male, anal appendages. The same, male, anal appendages. Argia moesta putrida, male, anal appendages. The same, male, anal appendages. Prats LXIX 145 161 @ r=) aol PLATE LXX Thoracic and Abdominal Structures of Adults o, 159. o. 160. ig. 161. ig. 162. . 163. o, 164. @. 165. o. 166. . 167. 168. ig. 169. g. 170. Nehalennia irene, male, anal appendages. The same, male, anal appendages. Enallagma hagen, male, anal appendages. The same, male, anal appendages. Ischnura posita, female, mesostigmal plates. Anomalagrion hastatum, female, mesostigmal plates. Enallagma asperswm, male, ninth sternum. Anomalagrion hastatum, male, anal appendages. The same, male, anal appendages. Ischnura verticalis male, anal appendages. Enallagma doubledayi, male, right superior appen- dage seen from the left and above. Chromagrion conditum, female, mesostigmal plates and dorsum of prothorax. Ischnura posita, male, ninth sternum. Anomalagrion hastatwm, male, ninth sternum. Ischnura posita, male, anal appendages. Amphiagrion saucium, male, anal appendages Enallagma doubledayi, male, anal appendages. Enallagma carunculatum, male, right superior ap- pendage seen from the left and above. Tschnura posita, male, anal appendages. Amphiagrion sauciwm, male, anal appendages. Enallagma civile, male, right superior appendage seen from the left and above. Ischnura verticalis, female, mesostigmal plates. Amphiagrion saucium, female, mesostigmal plates. Nehalennia irene, female, mesostigmal plates. The same, male, ninth abdominal sternum. Pirate LXX Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. Fig. | Fig. Fig. Fig. tum. . Enallagma . Enallagma . Enallagma . Ischnura kellicotti. . Bnallagma 3. Hnallagma . Enallagma tum. 5. Lnallagma . Enallagma . Enallagma PLATE LXXI Anal Appendages of Adults . Ischnura kellicotti. . Enallagma . Enallagma . Lnallagma signatum. pollutum. caruncula- aspersum. ebrium. divagans. signatum. pollutwm. caruncula- aspersum. ebrium. divagans. ig. 198. 7.199, 200. 201. 202. ig. 203. ig. 204. ia. 205. ig. 206. ig. 207. ig. 208. ig. 209. ig. 210. 211. Enallagma Enallagma Enallagma Enallagma Enallagma Enallagma Enallagma Enallagma tum. Enallagma Enallagma Enallagma Enallagma Enallagma Enallagma civile. traviatum. calverti. cyathigerum. antennatum. exsulans. geminatum. caruncula- traviatum. calverti. cyathigerum. antennatum. exsulans. geminatum. Pirate LXXI 212 213 214. 215. 7. 216. sail 218. 219. 220. ae 299). 992 ig, 224. . 225. Enallagma pollutum, mesostigmal plates. . 226. » 221. r. 228. Puate LXXII Thoracic Structures of Adults . Enallagma civile, mesostigmal plates. . Enallagma cyathigerum, mesostigmal plates. Enallagma signatum, mesostigmal plates. Enallagma carunculatum, mesostigmal plates. Enallagma geminatum, mesostigmal plates. Ischnura verticalis, nymph. (See Plate LX XIII.) Enallagma traviatwm, mesostigmal plates. Enallagnia antennatum, mesostigmal plates. Enallagma exsulans, mesostigmal plates. Enallagma hageni, mesostigmal plates. Agrion maculatum, nymph. (See Plate LX-XIIT.) Enallagma calverti, mesostigmal plates. Enallagma divagans, mesostigmal plates. Enallagma doubledayi, mesostigmal plates. Enallagma ebrium, mesostigmal plates. Lestes forcipatus, nymph. (See Plate LX XIII.) Pirate LXXII @ 214 Cy Puate LXXIII Nymphs Fig. 217. Ischnura verticalis. Fig. 222. Agrion maculatum. Fig. 228. Lestes forcipatus. PLATE LXXIII . ELSA IVA AI 2 SS, by Terenas, ae al STN ar yor: INDEX. A Acanthomeride, 308, 312, 314, 354. Acer saccharum, 5, 7. Achatodes, 114. zee, 115. Acrobasis, 75. rubrifasciella, 76. Acrocercops, 67. venustella, 68. Acrolophide 45, 46-47. Acronycta, 113, 114, 115, 119. americana, 115. clarescens, 115. hamamelis, 113. populi, 115. Acronyctineg, 108, 113-115. Acroptera, 175, 178. Adelocephala, 144. bicolor, 144. bisecta, 144. Adiantum pedatum, 5. A®geria, 49. Amgeriide, 24, 48, 49-51, 52, 53. A@gerioidea, 27, 31, 48-51, 147, 148. 4éshna, 463. Aishnide, 451, 452, 454, 455, 456, 458, 459, 461 (see also Errata), 462, 463, 464. Agapema, 146. galbina, 146. Agaricus, 250. sp., 215, 216, 255. Agaristine, 109, 112-113. Aglais, 91. milberti, 91. Agonopteryx, 104, 105. nebulosa, 105. Agraulis, 92. vanille, 92. Agrion, 412, 417, 421, 442, 465, 466, 472. equabile, 465, 467-469. yakima, 438, 467. maculatum, 438, 465, 467, 468, 469- 471. virgo, 439. Agrionide, 413, 423, 430, 431, 432, 446, 450, 452, 454, 455, 456, 458, 459, 461, 462, 463, 464, 465, 466-476. Agrionineg, 421, 465, 466-476. Agromyzide, 166. Agrotine, 107, 109-110, 111. Agrotis, 109, 391. badinodis, 110. bicarnea, 110. Alfalfa, 202. Alge, 167, 193, 212, 214, 217, 218, 221, 222, 232, 239, 265, 275, 277, 280, 285, 316, 318, 319, 321. Allium tricoccum, 5. Alsophila, 127, 130. pometaria, 131. Alypia, 113. octomaculata, 113. Amblyscirtes, 81. vialis, 82. Ampelophaga, 139. myron, 140. versicolor, 140. Amphiagron, 465, 499, 500, 562. saucium, 465, 562-564. Amphibians, 265. Amphicarpa monoica, 4, 5, 7. Amphion, 139. nessus, 140. 590 INDEX Anacampsis, 102. rhoifructella, 103. sp., 103. Anaea, 93, 94. andria, 89, 94. Anaeineg, 89, 94. Anastechus, 391. nitidulus, 393. Anax junius, 412. Ancylis, 52, 54. comptana, 54. diminutana, 54. platanana, 54. Andrena, 390, 391. Androprosopa, 290. Anemone, 211. virginiana, 5. Anemonella thalictroides, 5. Anemopoda, 441. Ania, 129. limbata, 131. Anisoptera, 411, 413, 421, 423, 430, 437, 442, 444, 445, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459, 460, 462, 463. Anisota, 144. consularis, 144. senatoria, 144. skinneri, 144. stigma, 144. virginiensis, 144. Anisozygoptera, 446, 447, 448, 449, 464. Anomalagrion, 465, 500, 501, 575. hastatum, 465, 575-577. Anomis, 107, 115. erosa, 115. Anosia, 94. plexippus, 94. Anthomyia, 367. , sp., 367. Anthomyiide, 166, 176, 178. Anthophora, 391. Anthrax, 391. albofasciatum, 395. simson, 393. _ Aphredoderus sayanus, 441. Antispila, 63. ampelopsisella, 63. cornifoliella, 63. Apantesis, 120. arge, 121. michabo, 121. - nais, 121. phyllira, 121. virgo, 121. Apatelodes, 132, 133. angelica, 134. torrefacta, 134. Apatelodine, 134. Apaturine, 89, 93-94. Apaturini, 94. Aphebantus, 391. mus, 392. Aphrosylus, 404. Apioceride, 173, 308, 318, 369, 373. Apple, 63. Apterygota, 454. Arachnida, 441. Aralia nudicaulis, 4, 5, 7. racemosa, 5. Archips, 55, 57, 58. argyrospila, 29, 58. cerasivorana, 55, 58. fervidana, 58. magnoliana, 58. obsoletana, 58. parallela, 58. rosaceana, 58. Archizygoptera, 446, 448, 449. Arctiide, 107, 114, 116, 119-121, 346. Argia, 417, 421, 480, 444, 465, 499, 500, — 501, 562. apicalis, 445, 465, 502, 503-506, 507, 512, 514. fumipennis, 465, 502, 503, 506-507. moesta putrida, 438, 465, 501, 502, 503, 507-510. putrida, 440. sedula, 465, 502, 503, 510-511. : tibialis, 440, 465, 502, 503, 511-514. violacea, 465, 502, 503, 515-517. INDEX Argynnini, 90, 91-92. Argynnis, 92. cybele, 92. Argyrameba, 390. obsoleta, 395. edipus, 392. Argyresthia, 98. freyella, 98. Argyrotoxa, 56. albicomana, 57. bergmanniana, 57. Aristotelia, 101, 102, 103. physaliella, 101, 103. salicifungiella, 103. Army-worm, 259. Arrhenurus spp., 441, 445. Arthrocera, 340. Arthroceratine, 340. Arthropeas, 346, 347, 352. Arthropoda, 441, 454. Aschiza, 175, 178. Asclepias phytolaccoides, 5. syriaca, 5. Asilide, 175, 308, 310, 312, 313, 354, 359, 361, 362, 369, 370, 371, 373- 389, 390. Asiloidea, 308, 369-396. Asilus, 384, 385. estuans, 388. herminius, 386. interruptus, 387. notatus, 374, 375, 377, 384, 385-386. sericeus, 377, 386-387. Asindulum, 246. Aster levis, 5. multifiorus, 5. spp., 7. Atherix, 362, 363, 364. Atreus, 136. plebeia, 140. Atrichopogon, 284. Atteva, 71, 72. aurea, 72. Attevide, 69, 70, 71-72. 591 Automeris, 142, 143. incarnata, 143. io, 143. leucana, 143. pamina, 143. B Balsa, 116, 117. malana, 117. Banchus, 391. Basilarchia, 93. archippus, 93. arthemis, 93. astyanax, 93. Basilarchine, 89, 93. Basilona, 144. imperialis, 144. Bedellia, 65. somnulentella, 65. Bees, 375, 379, 390, 391. hive, 381, 384. Belostoma, 441. Bembecia, 49, 50. marginata, 51. Beridine, 317, 331. Bezzia, 284. Bibio, 292, 299, 300, 301, 302. femoratus, 300. marci, 300. Bibiocephala, 276. grandis, 276. sp., 275. Bibionidsw, 167; 170, 174, 182, 184, 186, 189, 247, 292, 293, 297, 298-300, 301. Bibionoidea, 182, 245, 291, 292, 297— 305. Bidens frondosa, 296. Birds, 375, 445. Bittacomorpha, 239, 240. clavipes, 239-240. Blackberry, 63. Black-flics, 302. Blepharoceride, 170, 182, 183, 187, 189, 263, 264, 274-276. Blood-worms, 287. ~ 592 Bolitophila, 247, 248. cinerea, 248. disjuncta, 248. hybrida, 248. montana, 248. Bolitophilide, 166, 170, 182, 184, 189, 245, 246, 247-248. ; Bombycide, 123, 124-125. Bombycoidea, 33, 96, 107, 123-125. Bombyliide, 175, 308, 310, 312, 313, 369, 870, 374, 389-396. Bombylius, 390, 391, 392. major, 390. minor, 390. pumilus, 389. Bombyx, 124. mori, 125. Borborus, 302. Borers, 37, 38, 39, 40. sod-, 45, 46. Botrychium virginianum, 5. Brachista pallida, 442. Brachycera, 165, 167, 168, 172, 174-175, 177, 178, 179, 180, 181, 307-407. Breeze-flies, 355. Brenthia, 47, 48, 63. pavonacella, 48. Brenthis, 92. myrina, 92. Brephos, 127, 130. infans, 131. Bucculatrigide, 60, 61, 64, 65. Bucculatrix, 64. pomifoliella, 64. trifasciella, 64. sp., 64. Buffalo-gnats, 302. Butalis, 100. Buttonbush, 225. (© Cenurgia, 118. crassiuscula, 118. erechtea, 118. Calicodoma, 391. INDEX Callosamia, 146. angulifera, 146. promethea, 146. Callostoma, 391. Caloptenus spretus, 391. Calopterygide, 413. Calopteryx, 413, 442. virgo, 439. Calpodes, 79, 81. ethlius, 82. Cameraria, 64, 67, 68, 69. hamadryadella, 68. ostryella, 68. tubiferella, 68. Campsicnemus, 404. Camptocladius, 288, 289. Canarsia, 76. ulmiarrosorella, 76. Carpinus earoliniana, 5. Carpocapsa, 52, 53. latiferreanus, 54. pomonella, 58, 54. saltitans, 54. Carrot, wild, 319. Carya ovata, 5. Catherinea undulata, 5. Catocala, 117. aholibah, 118. briseis, 118. ilia, 118. illecta, 118. innubens, 118. neogama, 118. pacta, 118. sponsa, 118. unijuga, 118. verecunda, 118. Catocaline, 109, 110, 117-118. Cattle, 358. Ceanothus americanus, 5 (see Errata). Cecidomyia pini-inops, 295. resinicoloides, 295. Cecidomyiide, 166, 167, 170, 174, 178, 180, 182, 188, 185, 186, 189, 292, 293-297, 315. Cecidomyiine, 294, 295. INDEX Cecidomyioidea, 182, 291, 292-297. Celastrus scandens, 5. Cemonus, 391. Cenopis, 58. chambersana, 58. Centrobia odonate, 442. _Cerambycide, 374, 386. Ceratocampide, 140, 141, 143-144. Ceratomia, 137. amyntor, 140. undulosa, 140. Ceratopogon, 282, 283. Ceratopogonide, 170, 174, 182, 185, 187, 190, 280; 281-284. Ceraturgus, 375, 379. cruciatus, 376, 379-380. Cercyonis, 95. alope, 95. Ceroplatus, 261-262. sesioides, 261. Cerurine, 134. Charadra, 116, 119. deridens, 116. Charidryas, 92. nycteis, 93. Chironomide, 17, 167, 170, 173, 177, 182, 185, 186, 187, 190, 245, 263, 275, 277, 280, 281, 284-290, 291, 298, 401, 440, 441. Chironomineg, 284, 285, 286, 287-290, 291. Chironomoidea, 182, 280-291. Chironomus, 174, 282, 287, 288, 289, 291. Chlaenogramma, 137. jasminearum, 140. Chloridea, 112. obsoleta, 112. virescens, 112. Chlorippe, 93, 94. celtis, 94. clyton, 94. Chloropide, 166. Choreutis, 47, 48, 63. gnaphiella, 48. inflatella, 48. 593 Chromagrion, 427, 465, 499, 500, 564. conditum, 465, 565-567. Chrysanthrax fulvohirta, 391, 392. Chrysopeleia, 104. ostryaeella, 104. Chrysopeleiide, 98, 99, 104. Chrysophanus, 83, 84. thoe, 85. Chrysopila, 363, 364-365. feeda, 367. ornata, 365, 367. quadrata, 365, 367. sp., 365, 367. Chrysops, 356, 357-358. Chrysotus, 404. Cicindela, 391. Cinclidia, 93. harrisii, 93. Cingilia, 129. catenaria, 131. Cinglis, 128. similaria, 131. Cirphis, 110, 111. phragmitidicola, 112. unipuncta, 112. Cissia, 95. eurytus, 95. Citheronia, 143. regalis, 144. Clegs, 355. Cleora, 130. pampinaria, 131. Clitellariine, 316, 317, 322-331. Clusiodes flaviseta, 403. Cocceius, 82. pylades, 82. Cocytius, 136. anteus, 140. Coenagrionide, 417, 422, 430, 431, 432, 440, 441, 443, 447, 452, 454, 455, 456, 458, 459, 461, 462, 463, 464, 465, 476-577. Cenagrionine, 438, 465, 499-577. Cenomyia, 307, 352. ferruginea, 351, 354. pallida, 351, 852, 353-354. 594 Cenomyiide, 175, 308, 309, 311, 313, 814 (see also Hrrata), 351-354. Coleophora caryefoliella, 98. malivorella, 98. vernonizella, 98. Coleophoride, 96, 98. Coleoptera, 20, 178, 302, 350, 372, 381, 385, 386. parasites of, 368, 391. Colletes, 391. Convolvulus sepium, 5. Copaxa, 145. lavendera, 146. Copepoda, 441. Coptodisea, 63. juglandiella, 63. splendiforella, 63. Coptotriche, 63, 64. zelleriella, 64. Cora, 451, 457. Cordyla, 260. Corethrine, 263, 277, 278. Cornus alternifolia, 5. circinata, 5. paniculata, 5. Corydalis, 442. Corylus americana, 5. Corynoneura, 288. Cosmopterygide, 98, 99, 106. Cosmopteryx clandestinella, 106. Cosmotriche, 124. potatoria, 124. Cosside, 39, 40-41. Cossine, 41. Cossoidea, 22, 26, 31, 37, 38-41. Cosymbia serrulata, 131. Crambine, 72, 73, 74. Crambus caliginosellus, 74. trisectus, 74. vulgivagellus, 74. Crane-flies, 196. Crappie, 441. Cremastobombycia, 68. solidaginis, 68. Cressonia, 135, 137. juglandis, 140. INDEX Cricotopus, 288, 289. Crucifere, 166. Crustacea, 217, 218, 285, 316, 318, 319, — 321, 440, 441. Cryptotenia canadensis, 5. Ctenophora abdominalis, 200. fumipennis, 195. Ctenophorine, 191, 193, 194-195. Ctenucha, 119, 120. virginica, 121. Cuculliine (see Errata), 107, 108, 110. Culicide, 167, 170, 182, 183, 187, 189, 2638, 264, 276-279, 280, 441. Culicine, 263, 277, 278. Culicoidea, 182, 263-280. Culicoides, 282, 283, 284. Cutworms, 391. Cyaniris, 84. - ladon, 85. Cyclops, 440, 441. Cyclorrhapha, 165, 168, 171, 172, 173, 175-177, 178, 179, 180. Cylindrotoma, 211. Cylindrotomine, 208, 209, 210-211, 238. Cymatophora, 130. ribearia, 131. Cyrtide, 308, 310, 311, 313, 368-369. Cyrtoidea, 308, 368-369. D Damsel-flies, 411-587. Damsel-fly, 413. Daphnia, 440, 441. Darapsa, 139. pholus, 140. Daremma, 137. catalpe, 140. Dasychira, 122. pudibunda, 122. Dasyllis, 375, 379, 380-381. spp., 376, 380, 381, 382. Dasypogon cruciatus, 379. Datana, 125, 133. angusii, 134. chiriquensis, 134. contracta, 134. P. INDEX 595 Datana—Continued. drexelii, 134. integerrima, 134. major, 134. ministra, 134. modesta, 134. palmii, 134. robusta, 134. Deidamia, 139. inscriptum, 140. Deilephila, 138. lineata, 140. Depressaria, 104, 105. heracliana, 105. Dermatina, 370. Deromyia, 376, 384. discolor, 374, 375, 376, 384-385. winthemi, 374, 376, 385. Desmia, 77. funeralis, 77. Desmodium grandiflorum, 5. rigidum, 5. Dexiide, 167. Diacrisia, 120. virginica, 121. Diadocidiine, 249, 251. Diamesa, 289. Diatoms, 218, 275, 285, 319, 440. Dichromia, 391. Dicranomyia, 211, 212, 227. simulans, 213-214. Dicranota, 216, 217, 218, 219, 220. bimaculata, 219-220. sp., 219. Dictyoneuride, 447, 448, 449. Dilophonota, 138. alope, 140. ello, 140. Diogmites discolor, 384. Dioptide, 125, 126, 134. ~ Diptera, 17, 161-409, 412, 428, 441, 445. aquatic, 167. inquilinous, 390. parasitic, 167, 391, 394. predaceous, 167, 370. Ditomyia, 247, 248 368, 369, 370, 390, Dixide, 170, 182, 184, 187, 189, 263, 277, 279-280. Dolba, 136. hyleus, 140. Dolichopezine, 191, 193. Dolichopodide, 167, 170, 175, 178, 308, 3810, 312, 314, 399, 400, 401, 402, 403-407. Dolichopus, 404, 406. eneus, 406. Dragon-fly, 413. Drapetis, 175, 402, 405. nigra, 402, 403. Drosophilide, 166. Dryocampa, 144. rubicunda. 144. E Echinocystis lobata, 5. Eecpantheria, 120. deflorata, 121. Ectropis, 130. erepuscularia, 131. Elachista, 65, 98, 104, 106. prelineata, 106. Elachistide, 62, 96, 98, 99, 100, 104, 106, 148. Eleagnus argentea, 5. Elateride, 386. Elis sexcincta, 391. Elliptera, 231. clausa, 226. omissa, 226-227. Empididex, 164, 167, 178, 308, 310, 312, 313, 314, 399, 400-403. Empididoidea, 308, 370 (see Errata), 399-407. Enallagma, 423, 465, 500, 501, 517. antennatum, 438, 445, 465, 518, 520, 521-524. aspersum, 465, 519, 520, 524-525. calverti, 465, 476, 500, 518, 520, 521, 525-528, 536. carunculatum, 442, 465, 476, 518, 519, 520, 527, 528 (see also Errata)— 531, 532, 533,.534, 539, 540, 550. 596 INDEX Enallagma—Continued. Civile, 445, 465, 476, 518, 519, 521, 527, 528, 581-534, 5389, 540, 550. cyathigerum, 465, 500, 518, 520, 521, 528, 534-536. divagans, 465, 476, 520, 521, 536-538. doubledayi, 465, 476, 519, 521, 528, 538-540. ebrium, 465, 520, 540-541. exsulans, 442, 465, 518, 520, 521, 522, 524, 538, 542-544, 559. geminatum, 442, 465, 517, 519, 520, 544-547. hageni, 439, 445, 465, 517, 520, 534, 547-550. piscinarium, 465. pollutum, 465, 518, 519, 521, 550- 553. t pulchellum, 439. signatum, 438, 443, 465, 518, 519, 521, 544, 553-556. traviatum, 465, 518, 519, 521, 556- 559. Enarmonia, 52, 54. fana, 54. Ennomine, 127. Ennomos, 127, 129. magnarius, 131. subsignarius, 131. Entoparasites, 166. Eois, 128. inductata, 131. Epagoge, 57, 58. sulfureana, 58. Epallagide, 447. Epargyreus, 82. tityrus, 82. Epermenia pimpinella, 97. Epermeniide, 59, 95, 96-97, 147. Ephemeride, 21, 441, 445. Ephestia, 74, 75. kuehniella, 76. Ephydride, 167. Epiblemide, 47, 51, 52-64. Epinotia, 52, 53, 54. piceafoliana, 54. saliciana, 54. Epiophlebia, 446. Epipaschiine, 72, 73, 77-78. Epiphragma, 221, 224. fascipennis, 224-225. pavonia, 224. Episimus, 55. argutanus, 56. Equisetum arvense, 5, 7. hyemale, 5. Erannis, 131. tiliaria, 131. Erax, 376. estuans, 374, 377, 388-389. ambiguus, 387. lateralis, 387. _ maculatus, 374, 377, 387-388. Erigeron, 260. philadelphicus, 5. ramosus, 5. Eriocera, 233. Eriocraniide, 28, 24, 25, 26, 35, 37, 44, 48, 59, 60, 62. Erioptera, 228, 231-232. sp., 231, 237. Eriopterine, 207, 208, 209, 210, 217, 227-232, 236, 237, 238. Eriopus, 110, 112. floridensis, 112. e Esox vermiculatus, 441. Estigmene, 120. acraea, 121. ‘ Eucephala, 169, 182, 190, 245-291. Euchetias, 119. ; egle, 121. Euclea, 43. chloris, 44. delphinii, 44. Bucleide, 24, 42 (see Errata), 43-44. Eucleoidea, 25, 26,29, 31, 37, 41-44, 62. Eucosma, 52, 53. scudderiana, 54. strenuana, 54. Eudamus, 82. proteus, 82. Euforcipomyia, 283. Eugnoriste, 246, 260. Eulonche, 114, 119. oblinita, 115. Eumenes, 391. Eunetis, 117. blandula, 118. grynea, 118. ultronia, 118. Eupachygaster, 335, 336-337, 340. henshawi, 336, 337, 338-340. punctifer, 337, 338, 339. tarsalis, 336. Eupackardia, 146. calleta, 146. Euparthenos, 118. nubilis, 118. INDEX Exartema—Continued. permundanum, 56. sciotoanum, 55, 56. BExechia, 252, 254-255. nativa, 255. 597 Exoprosopa fascipennis, 391, 393. F Fanniine, 176, 177. Feniseca, 78, 83, 84. tarquinius, 85. Ferns, 255, 325. Fishes, 411, 441. Flesh-flies, 166. Flies, 411. Fomes, 226. Forcipomyia, 282, 283, 291, 404. Euparyphus, 329. Euphea, 451, 457. Eupheades, 86. palamedes, 86. troilus, 86. Euphydryas, 92. pheton, 93. Eupleine, 89, 94. Euproctis, 122. chrysorrhea, 123. Eupterotide, 132. Euptoieta, 92. claudia, 92. Eurema, 88. nicippe, 88. Eurymus, 88. philodice, 88. Euthisanotia, 113. grata, 113. unio, 113. Euvanessa, 91. antiopa, 91. Euxesta, 336, 342. Evippe, 102. prunifoliella, 103. Exartema, 55, 56. concinnanum, 56. ferriferanum, 55, 56. inornatum, 56. nigranum, 56. Fungi, Galium Fragaria americana, 5. Fraxinus americana, 5, 7. 212, 215, 216, 221, 442. G Gadflies, 355. triflorum, 5. Galleria melonella, 74. Galleridex, 26. Gallerinw, 32, 69, 72, 73-74. Gastrophilide, 167. Gelechia, 103. cercerisella, 104. discoocellella, 104. serotinella, 104. Gelechiide, 28, 97, 98, 99, 100, 101-104, 127, Gelechioidea, 28, 33, 96, 98-107, 148, 149. Gentiana quinquefolia, 5. Geometride, 29, 125, 126-131, 134. Geosargineg, 317, 318, 322, 331-334, 335. Geosargus, 322, 323, 331, 332, 334. nubeculosus, 332. sp., 333-334. viridis, 333, 334. Geranomyia, 212. 135. 226, 242, 247, 250, 252, 2538, 254, 258, 260, 265, Fungus-gnat, 250. 598 ; INDEX Giant Skippers, 79. Glaphyroptera oblectabilis, 253. Glutops, 340. Gnophomyia, 227, 229, 230, 231. tristissima, 228, 230-231. Gnorimoschema, 103. gallesolidaginis, 104. lavernella, 101, 104. Gomphide, 446, 452, 454, 455, 456, 458, 459, 461, 462, 463, 464. Gomphus, 430, 463. Goniops, 355, 356-357. chrysocoma, 357. Gracilaria, 26, 60, 66. negundella, 60, 68. sassafrasella, 60, 68. violacella, 68. Gracilariide, 61, 62, 63, 65-68, 69. Gracilariine, 66, 68. ; Gracilarioidea, 23, 26, 31, 58-69, 147. Graptolitha, 110. . antennata, 110. laticinerea, 110. Grasses, 204, 206, 255. . H Hadena, 110, 112. vulgaris, 112. Hadenine, 108, 110-112. Hematopsis, 126, 127, 129. grataria, 131. Halictus, 391. Halisidota, 119. carye, 121. tessellaris, 121. ) Hamamelis virginiana, 5. Hapalia, 110. incivis, 110. Haploa, 120. clymene, 121. Harmologa, 57, 58 fumiferana, 58. Harpyia, 133. borealis, 134. Harrisina, 44. americana, 44, Hartomyia, 284. Helianthus divaricatus, 5. hirsutus, 5, 7. Heliodinide, 45, 47-48, 63. Heliozelide, 24, 59, 60, 62-63. Helobia, 227, 228-229, 230, 231, 237. punctipennis, 228, 229-230. Hemaris, 138. diffinis, 140. gracilis, 140. thysbe, 140. Hemerocampa, 121, 122. leucostigma, 123. Hemileuca, 142. burnsi, 143. maia, 143. olive, 143. Hemileucide, 140, 141, 142-143. Hemimene, 52, 54. _ incanana, 54. Hemipenthes, 391. Hemiptera, 441. ' Heodes, 83, 84. hypophleas, 85. Hepatica acutiloba, 5. triloba, 7. Hepialide, 23, 24, 37, 38, 40. Hepialoidea, 22, 30, 37-88, 39, 41. Heracleum lanatum, 5. Hermetia, 316, 322, 323, 345. illucens, 323-324. mucens, 323. Herse, 136. cingulata, 140. Hesperiide, 27, 78, 79, 80-82. Hesperinus, 247. Hesperioidea, 78. Hessian fly, 167. Heterina, 417, 426, 434, 435, 444, 465, 466, 467, 471. americana, 445, 465, 471-474, 475. titia, 465, 471, 474-476. tricolor, 476. Heterocampa, 132, 134. bilineata, 134. guttivitta, 134. Heterocampine, 134. Heterodactyla, 307 INDEX 599 Heteromeringia, 342. Heteromyia, 284. Heteropezine, 295. Hexatoma, 233. Hexatomine, 207, 208, 209, 210, 223, 232-233, 237, 238. Hippoboscide, 167. Hogs, 359. Holeocephala, 375. Homoeodactyla, 307 (see Errata). Homopyralis, 107, 114. discalis, 115. Honey-bee, 412. Hoplomerus, 391. Horse-flies, 355. House-fly, 166. Hyalanthrax, 391. alternata, 393. hypomelas, 393. lateralis, 393. Hydrachnide, 441. Hydria, 128. undulata, 131. Hydriomenine, 127. Hydrophorus, 404. Hymenoptera, 21, 167, 178, 316, 381, 428, 445. -Aculeata, 391. parasitic, 167, 254, 255, 300, 355, 357, 442. Hyparpax, 133. aurora, 134. Hypenine, 107, 109, 116-117. Hyperparasites, 370, 391. Hyphantria, 120. cunea, 121. Hypocera, 176. Hypocolpus, 46. mortipennellus, 47. Hypsopygia, 74. costalis, 74. Incisalia, 84. niphon, 84. Impatiens biflora, 5. Insecta, 17, 441. Iphiclides, 85, 86. ajax, 86. Ischnura, 435, 465, 500, 501, 567. elegans, 439. kellicotti, 465, 568-570. posita, 465, 568, 570-572. verticalis, 423, 438, 439, 442, 443, 445, 465, 555, 568, 570, 571, 572-575. Isia, 120. isabella, 121. J Johannsendmyia, 284. Juniperus communis, 5. virginiana, 5, 7. Junonia, 91. coenia, 91. K Krigia amplexicaulis, 5. L Laertias, 86. philenor, 86. Lagoa crispata, 48. Lanthape platanella, 78. Lapara, 137. bombycoides, 140. coniferarum, 140. Laphria, 373, 375, 379, 381. Laphygma, 111. frugiperda, 112. Lasiocampa, 124. quercus, 124. Lasiocampide, 28, 123-124. Laverna, 100. brevivittella, 100 (see Errata and Addenda). Lavernide, 98, 99-100, 106. Leaf-miners, 38, 46, 59. Leia, 250, 252-253, 254, 255, 256, 259. oblectabilis, 253-254. Lepidoptera, 17-159, 178, 391, 445. Lepisesia, 139. gaure, 140. juanita, 140. Lepomis gibbosus, 441. 600 INDEX Leptide, 167, 175, 308, 309, 311, 313, 346, 347, 352, 354, 362-367. Leptine, 362, 363. Leptis, 363, 364, 367. ornata, 365. quadrata, 367. Leptocera, 302. Leptogaster, 370, 374. flavipes, 373, 374, 375, 377-379, 390. Lestes, 418, 421, 422, 427, 480, 435, 438, 439, 440, 442, 444, 451, 465, 477, congener, 465, 477, 478, 479-482. disjunctus, 465, 476, 478, 479, 481, 482-483, 485, 487. eurinus, 465, 478, 479, 483-485. forcipatus, 465, 476, 478, 479, 483, 485-487, 490, 492, 494, 496. inaequalis, 465, 478, 479, 485, 487-489. rectangularis, 448, 465, 478, 479, 483, 487, 489-492, 494, 496. : uncatus, 465, 477, 478, 479, 492-494, 496. unguiculatus, 465, 478, 479, 492, 494— 496. vigilax, 445, 465, 478 (see also Errata), 479, 485, 489, 496-499. Lestine, 421, 430, 459, 463, 465, 477-499. Lestremine 295. Leucanthiza, 67. amphicarpeefoliella, 68. ostensackenella, 68. Libellulide, 451, 452, 454, 455, 456, 458, 459, 461, 462, 463, 464. Limnobia, 192, 212, 213, 214-215, 223, 236. fascipennis, 224. immatura, 214, 215, 216. punctipennis, 229. simulans, 213. triocellata, 215-216. Limnobiide, 170, 174, 182, 183, 185, 188, 190, 191, 192, 207-238, 305-307. Limnobiine, 208, 209, 210, 212-216, 228, 237. Limnophila, 221-222, 224, 225, 229, 234, luteipennis, 222-223. sp., 224. tenuipes, 223-224. Limnophiline, 209, 210, 220-226, 228, 238. Liogma, 211. Liparide, 29, 107, 119, 121-123. Lithocolletine, 66, 67-68. * Lithocolletis, 59, 67, 68. argentinotella, 67, 68. lucidicostella, 67, 68. tiliacella, 67, 68. Locust, 391. Lonchea, 336, 342. polita, 336. Lonchopteride, 172, 175, 178. Lonicera sullivantii, 5. Lophoptilus, 100. eloisella, 100 (see Errata and Ad- denda). Lycenide, 27, 78, 79, 83-85, 95. Lycia, 131. ' cognataria, 131. Lycophotia, 110, 112. margaritosa, 112. Lymnadide, 94. Lyonetiide, 59, 60, 61, 64-65, 148. M Macroceride, 166, 173, 182, 190, 246, 260. Macrosargus, 331. Malacosoma, 124. americana, 124. disstria, 124. Mamestra, 391. Mammals, 265, 375. Maple, 3, 4. March-fly, 300. Marmara, 67, 68. salictella, 68. Marumba, 135, 138. modesta, 140. Masicera, 391. Maurina, 264, 265. californensis, 265, 266-267. Medeterus, 175, 402, 404, 405, 406. ambiguus, 405. Megachile, 391. Megalopygide, 42-438, 44. INDEX 601 Meganeuride, 448, 449. Megathymide, 78, 79-80. Megathymus yuccae, 80. Melalopha, 132. albosigma, 134. apicalis, 134. inclusa, 134. Melalophine, 134. Meliana, 111. albilinea, 112. Melilotus alba, 5. Melitzini, 90, 92-93. Mellisopus, 53. latiferreanus, 53. Meloe, 390. Memythrus, 49, 50. asilipennis, 51. dollii, 51. Menesta, 105. albaciliaeella, 106. Menispermum canadense, 5. Meracantha contracta, 350. Meroptera, 75. pravella, 76. Metriocnemus, 288, 289, 290. Miastor, 405. Microchrysa, 332, 334. polita, 333, 334, 346. Microlepidoptera, 151. Micropterygide, 35. Micropterygoidea, 22, 24, 30, 35-37, 149. Micropteryx, 20. Milkweed, 372. . Mineola, 75. indiginella, 76. Misgomyia, 340. Mitella diphylla, 5, 7. Mites, 441, 445. Mitura, 84. damon, 85. . Mnemonica auricyanea, 35, 37. Mnium sp., 5. Momine, 108, 116. Momphide, 106. Monarda fistulosa, 5. Monardia sp., 296. Monima, 110, 111. alia, 112. Mosquitoes, 167, 356, 411, 416, 440, 445. Mosses, 3, 4, 7, 211. ‘Musca clavatus, 372. fenestralis, 399. illucens, 323. polita, 334. Muscide, 166, 168, 172, 178, 302. Mushrooms, 254, 259. Mycetobia, 191, 241, 242, 243, 244, 248. divergens, 241, 244-245, 284. marginalis, 244. sordida, 244. Mycetobiine, 247. Mycetophila, 252, 253, 260 . persice, 244. signata, 252. Mycetophilide, 166, 170, 173, 174, 182, 184, 185, 186, 189, 191, 241, 245, 246, 247, 248-258, 259, 260, 261. Mycetophiline, 249, 251-255, 256, 258, 259. Mycetophiloidea, 167, 182, 190, 191, 245, 246-262. Mycoma brevivittata, 257-258. Mydaide, 175, 307, 308, 310, 311, 313, 369, 370-373. Mydas clavatus, 371, 372-373. fulvipes, 372. N Nacophora, 129. queruaria, 131. Nehalennia, 427, 465, 499, 500, 559. irene, 465, 559-561. Nematocera, 17, 167, 168, 169, 170, 171, 172, 173-174, 177-178, 180, 181, 182-307, 308, 440, 445. Nematode parasites, 242, 363, 366. Nemestrinide, 173, 308, 309, 313, 368, 373. Nemotelus, 322, 324. pantherinus, 324 (seo Errata). uliginosus, 324. Neoceratopogon, 283. 602 INDEX Neopachygaster, 335, 340. maculicornis, 335, 336, 340. Nepticula nyssefoliella, 62. platanella, 62. Nepticulide, 26, 29, 41, 48, 53, 59, 60, 61-62, 65. Neuroptera, 20. Noctua, 110, 391. clandestina, 110. Noctuide, 107-119. Noctuoidea, 26, 33, 96, 107-123. Notodontide, 125, 132-134. Notodontine, 134. Notodontoidea, 34, 76, 125-134. Notonecta, 441. Nycteolide, 119. Nymphalide, 78, 79, 87, 88-95, 148. Nymphaline, 89, 90-93, 94. O Ocydromia, 400. Odonata, 411, 423, 428, 438, 441, 446, 448, 449, 451, 454, 457. Odontomyia, 317, 318, 320-321, 325. cincta, 321, 322. extremis, 321. vertebrata, 321-322. Odynerus, 391. Gcophoride, 98, 99, 104-105. Gineine, 32, 90, 95. Gineis, 78, 95. semidea, 95. Gostride, 167. Oiketicus, 40. abbotii, 40. Olbiogaster, 241, 242. ‘Olene, 122. manto, 122. Olethreutes, 55, 56. malachitana, 56. niveiguttana, 56. Olethreutide, 51, 52, 54-56. Oligoneura, 167, 169, 182, 245, 291-305. Ophion, 391. Ornix, 59, 66. conspicuella, 68. crategifoliella, 68. prunivorella, 68. Orphnephila, 290. testacea, 290, 291. Orphnephilide, 170, 173, 182, 189, 280, 281, 290-291. : Orthocladius, 289, 290. Orthogenya, 307, 308, 314, 339-407 Orthoptera, 456. Orthorrhapha, 167, 169, 170, 171, 172, 173-175, 177-178, 179, 180-407. ‘Osmia, 391. Osmorhiza longistylis, 4, 5, 7, 10. Ostrya virginiana, 5. Oxycera, 322, 324-325, 329. . albovittata, 325, 330, 331. aldrichi, 325, 329-330. approximata, 325, 326-327. centralis, 325, 326, 327. crotchi, 325, 328-329. maculata, 331. picta, 325, 331. trilineata, 324. unifasciata, 327, 328. variegata, 325, 327-328, 329, 330. Oxyptilus, 70, 71. tenuidactylus, 71. P Pachygaster maculicornis, 336. pulcher, 339. | Pachygasterine, 317, 318, 334-340, 344 Pachyrrhina, 196, 207. ferruginea, 198, 199, 202, 206. Paleoplatyura, 247, 248. aldrichi, 248. johnsoni, 248. Paleacrita, 131 (see Errata and Ad- denda). vernata, 127, 131. Paleodictyoptera, 446 447, 448, 449. Paleophlebia, 446. Palpomyia, 283, 284. Panolis, 391. INDEX Pantagrapha, 77. limata, 77. Paonias, 135, 138. Papilio, 20, 86. brevicauda, 86. daunus, 86. eurymedon, 86. glaucus, 86. machaon, 86. polyxenes, 86. rutulus, 86. thoas, 86. zolicaon, 86. Papilionide, 78, 79, 85-86, 87. 90, 106. Papilionoidea, 23, 24, 27, 32, 65, 69, 76, 78-96, 147, 148, 151. Parabezzia, 284. Paralogide, 448, 449. Paramecium, 440, 441. Parasites of Coleoptera, 368, 391. of Diptera, 242, 254, 255, 304, 355, 357, 363, 366, 391. of Hymenoptera, 391, 394, 395. of Lepidoptera, 191. of spiders, 368, 369. of Zygoptera, 441, 442, 445. Parsnip, wild, 319, 320. Parectopa, 66. : lespedezefoliella, 68. Salicifoliella, 68. Parharmonia, 50. Pini, 51. : Pedicia, 216, 217, 218, 219. albivitta, 218. rivosa, 217. Pediciine, 208, 209, 210, 216-220, 227. 237, 306. Pedicularis canadensis, 5. Pelopzus, 391. cementarius, 395. Penthoptera, 222, 233. Perca flavescens, 441. Perch, common, 441. Pirate, 441. yellow, 441. Pericoma, 264, 265, 266, 267. californica, 266. californiensis, 265, 266. canescens, 270. townsvillensis, 265. Peronea, 56, 57. logiana viburnana, 57. minuta, 57. sp., 57. Phecasiophora, 57, 58. confixana, 58. Phalacrocera, 211. Pheocyma, 118. lunifera, 118. Philobia, 129. enotata, 131. Philosamia, 146. cynthia, 146. Phlebotomus, 265. Phlegethontius, 136. quinquemaculata, 140. sexta, 140. Phlyctenia, 77. ferrugalis, 77. Pholisora, 82. catullus, 82. Pholus, 139. achemon, 140. pandorus, 140. Phoride, 166, 175, 176, 178. Phryganidia californica, 134. Phthorimeza, 103. sp., 104. Phyciodes, 92. tharos, 93. Phycitine, 71, 72, 73, 74, 75-76. Phyllocnistide, 60, 61, 65, 68-69. Phyllocnistis, 68, 69. ampelopsisella, 69. insignis, 69. Physostegania, 130. pustularia, 131. Phytometra, 115. brassice, 116. Phytometrine, 108, 115-116 Pickerel, grass, 441. 603 604 INDEX Pieride, 78, 7%, 87-88. Pinipestis, 75, 76. zimmermani, 76. Pipunculide, 167, 172, 175. Plathypena, 116, 117. seabra, 117. Platygenya, 307, 308, 314-399. Platynota, 57, 58. flavedana, 57, 58. Platypezide, 166, 172, 175, 176. Platyptilia, 70, 71. _ earduidactyla, 71. Platyuride, 166, 170, 182, 185, 186, 190, 246, 247, 260-262. Plecia, 299. Plecoptera, 415, 426, 456, 458. Plodia, 74, 75. interpunctella, 76. Plusiodonta, 107, 114, 115. compressipalpis, 115. Plutella, 97. maculipennis, 98. Podosesia, 50. _ syringe, 29, 51. Polia, 112. meditata, 112. picta, 112. renigera, 112. Polychrosis, 55, 56. botrana, 56. slingerlandana, 56. viteana, 56. Polygala senega, 5. Polygonatum commutatum, 5. Polygonia, 91. comma, 91. faunus, 91. interrogationis, 91. progne, 91. Polylepta, 256, 258. leptogaster, 256, 257, 258. Polynema needhami, 442. ovulorum, 442. Polyneura, 169, 182, 190-245, 291. Polypori, 221, 226, 250. Polytoma, 396. Polytrichum commune, 5. Pomoxis annularis, 441. Pontia, 88. protodice, 88. rape, 88. Populus grandidentata, 5. Porthetria, 121, 122. dispar, 123. Potatoes, 324. Prionoxystus, 41. robinie, 40, 41. Probezzia, 284. Proctacanthus, 385. milberti, 374, 377, 385. philadelphicus, 377, 385. Proctotrypid, 357. Prodenia, 111. ornithogalli, 112. Prodoxide, 44, 45-46. Prodoxus quinquepunctella, 46. Proleucoptera, 65. smilaciella, 65. Prolimacodes, 43. scapha, 44. Promachus, 376, 383, 384. fitchii, 374, 375, 376, 383-384. sp., 376. vertebratus, 374, 375, 376, 383, 384. Protagrionide, 448, 449. Protodonata, 446, 447, 448, 449, 464. Protoparce carolina, 20. Protozoa, 440, 441. Prunus serotina, 5. Psedera quinquefolia, 5. Pseudanaphora, 46. arcanella, 47. Pseudobezzia, 284. Pseudoculicoides, 282, 233, 284. Pseudohazis, 142. eglanterina, 143. Pseudosphinx, 139. . tetrio, 140. Psilocephala, 397, 398. hemorrhoidalis, 397-398. melampodia, 398. Psilocorsis, 104, 105. obsoletella, 105. quercicella, 105. INDEX 605 Psilopus, 404. Psorosina, 76. hammondi, 76. Psychide, 39-40. Psychoda, 264, 265, 266, 267-268. albimaculata, 267, 268, 272. alternata, 267, 268. cinerea, 268, 271-272. domestica, 271, 272. floridica, 267. minuta, 267, 268-269, 272. nocturnala, 267. schizura, 267. 8p., 272. Superba, 268, 269-271, 272. Psychodide, 170, 182, 184, 187, 189, 263, 264-274. Psychomorpha, 113. epimenis, 113. Pteris, 325. Pterophoridz, 28, 69, 70-71. Pterophorus, 70, 71. Paleaceus, 71. Ptychoptera, 239, 240. sp., 240. Ptychopteride, 170, 182, 184, 188, 190, 191, 234, 238-241. Punkies, 282. Pygerine, 134. Pyralidide, 69, 70, 71, 72-78, 127, 135. Pyralidoidea, 24, 32, 69-78, 96, 147, 148. Pyraline, 73, 74, 75. Pyralis, 74. farinalis, 74. Pyrausta, 76, 77. fissalis, 76, 77. futilalis, 76, 77. illibalis, 76, 77. insequalis, 76, 77. Pyraustide, 23. Pyraustine, 73, 76-77. Pyromorphide, 42 (see also Errata), 44. Pyrrhia, 112. umbra, 112. Q Quercus alba, 5, 7. macrocarpa, 5. rubra, 5. velutina, 5. R Ranatra, 441. Rat, cactus, 345. Recurvaria, 102, 103. apicitripunctella, 104. variella, 101, 104. Reptiles, 265. Retinodiplosis, 295. Pini-inops, 295. Rhabdophaga podagre, 296. sp., 296. Rhacicerus, 346, 347. Rhagio punctatus, 243. Rhamphidia longirostris, 226. Rhamphidiine, 208, 209, 210, 226-227. Rhamphomyia dimidiata, 386, 401-402, 403. Rhaphidolabis, 217, 219, 220. tenuipes, 220. Rhegmoclema, 302. atrata, 301-302. Rhodophora, 111. florida, 112. gaure, 112. Rhus toxicodendron, 5. Rhyphide, 170, 182, 185, 188, 189, 190, 191, 234, 235, 241-245, 248. Rhyphus, 234, 235, 241, 242, 244, 245 alternatus, 243 (see Errata). punctatus, 235, 241, 243. Ribes cynosbati, 5. Robber-flies, 359. Rodents, 316. Rope-worm, 259. Rothschildia, 146. jorulla, 146. orizaba, 146. Rudbeckia hirta, 5. Rusticus, 84. scudderi, 85. 606 INDEX Sabulodes, 129. lorata, 131. transversata, 131. Salix glaucophylia, 5. Samia, 146. cecropla, 146. columbia, 146. gloveri, 146. rubra, 146. Sand-flies, 302. Sanguinaria canadensis, 5. Sanicula marilandica, 5. Sanninoidea, 50. exitiosa, 51. Saperda tridentata, 350. Saponaria officinalis, 5. Saprolegniales, 442. Sarcophagide, 166. Sargus, 332. viridis, 333. Sarrothripine, 109, 118-119. Sarrothripus proteella, 119. revayana, 119: Saturniide, 25, 27, 28, 128, 125, 135, 140, 141, 142, 144-146. Saturnioidea, 22, 34, 96, 123, 1385, 140- 146, 149. Satyrine, 78, 90, 94-95. Satyrodes, 95. canthus, 95. Scatopse atrata, 301. fuscipes, 301. recurva, 301. Scatopside, 167, 170, 174, 182, 184, 188, 189, 292, 297, 298, 299, 300-302. Scenopinide, 175, 307, 308, 310, 311, 313, 370, 371, 396, 398-399. Scenopinus, 398. fenestralis, 398, 399. Schizophora, 175, 176-177, 178. Schizura, 132, 133. concinna, 134. ipomes, 134. unicornis, 134. Sciara, 258, 260, 302. prolifica, 259. Sciaride, 166, 170, 173, 182, 184, 186, 190, 245, 246, 258-260, 294. Sciomyzide, 167. Sciophila, 251, 256, 257. brevivittata, 257. Sciophilingz, 249, 251, 252, 255-258. Screw-worm fly, 166. Scythridxz, 96, 98, 99, 100-101. Scythris eboracencis, 101. impositella, 101. Seaweed, 404. ’ Serromyia, 284. Shepherdia canadensis, 5 (see Er- rata). ; Sibine, 43. stimulea, 44. Simuliide, 170, 173, 174, 182, 184, 186, 189, -233, 279, 292, 297, 298, 302— 305. 4 Sitotroga, 103. ‘cerealella, 104. Smerinthus, 135, 1388. cerysii, 140. jamaicensis, 140. Smilax herbacea, 5, 7. Snake-worm, 259. Solidago canadensis, 5. Solva, 340. Sparganothide, 51, 52, 57-58. Sparnopolius fulvus, 391, 393. Sphecodina, 139. abbotti, 140. - Sphingide, 23, 24, 25, 29, 76, 135, 149, pie Sphingoidea, 34, 96, 135-140. Sphinx, 25, 137. ; chersis, 140. drupiferarum, 140. eremitus, 140. gordius, 140. kalmie, 140. lucitiosa, 140. ° Spiders, parasites of, 368, 369. Spogostylum, 391, 392. albofasciatum, 392, 395. anale, 392. simson, 392, 393-394, 395. INDEX 607 Steleopteride, 447. Stellaria, 211. Stenoma, 105. schlegeri, 106. Stenomide, 98, 99, 104, 105-106. Sterrhine, 127. Sthenopis thule, 38. Stratiomyia, 318, 320, 321 (see Er. rata), 325. marginalis, 320. meigeni, 319, 320. norma, 319-320, 321. Stratiomyiide, 167, 170 (see Errata), 175, 178, 180, 308, 309, 310, 312, 314, 315-346, 347, 354. Stratiomyiine, 316, 317-322. Stratiomyioidea, 308, 314-354. Strawberry, 7. Subula, 346. pallipes, 342. parens, 343. tenthredinoides, 344. Sunfish, 441. Symmerista, 133. albifrons, 134. Symmerus, 247, 248. Sympetrum striolatum, 439. Symphoromyia, 363, 364. Synanthedon, 50. acerni, 51. pictipes, 51. pyri, 51. scitula, 51. tipuliformis, 51. Synchloe, 88. genutia, 88. Syngrapha, 115. faleigera, 116. Syntomide, 107, 119. Syrphide, 164, 167, 175, 176, 178. Syssphinx, 143. Systenus, 405, 406. Systechus, 391. oreas, 393. Ay Tabanide, 167, 175, 231, 308, 309, 311, 312, 354, 355-361, 362. Tabanoidea, 308, 354-367. Tabanus, 356, 358-361. atratus, 359, 360. carolinensis, 360. costalis, 359, 360. epistates, 360. lasiophthalmus, 360. lineola, 359, 360. nigrescens, 359, 361. spp., 359. stygius, 359, 361. Tachinide, 167. Tachydromia, 401. Tanypine, 173, 281, 284, 285, 286, 287. Tanytarsus, 288, 289. Telea, 27, 145. polyphemus, 146. Telphusa, 102. palliderosacella, 103. quercinigracella, 103. Tenebrionide, 374, 386. Tephroclystis, 128. absinthiata, 131. interruptofasciata, 131. Thalassomyia, 289. Thalictrum dioicum, 5. Thanaos, 82. brizo, 82. lucilius, 82. Thecla, 84. acadica, 85. calanus, 85. liparops, 85. Theretra, 138. tersa, 140. Thereva hemorrhoidalis, 397. Therevide, 175, 307, 308, 310, 311, 313, 371, 396-398. Therevoidea, 308, 370, 396-399. Thiodia, 54. signatana, 54. Tholeria, 77. reversalis, 77. 608 INDEX Thorybes, 82. daunus, 82. Thrips, 404. Thrypticus, 404, 405. muhlenbergie, 404, 405. smaragdinus, 404, 405. Thuja occidentalis, 5. Thyridopteryx, 40. ephemereformis, 40. Tilia americana, 5. Tinea pellionella, 47. tapetzella, 399. Tineide, 45, 47, 106. Tineoidea, 28, 31, 44-48, 59, 60. Tiphia, 370, 391. Tipula, 191, 192, 193, 194, 195, 196, 207, 220. abdominalis, 197, 200. bicornis, 198, 199, 204, 205-206. clavipes, 239. cunctans, 197, 198, 204. eluta, 197, 198, 201, 203, 204. ferruginea, 206. serta, 198, 205. spp., 197, 198, 199, 200, 201-208, 218. trivittata, 198, 204-205. Tipulide, 170, 174, 180, 182, 183, 188, 190, 191-207, 208, 210, 238, 240, 264, 279, 299, 355. Tipuline, 191, 193, 194, 195-206. Tipuloidea, 182, 190-245. Tischeria, 63, 64. senea, 63, 64. heliopsisella, 63, 64. malifoliella, 63, 64. Tischeriide, 61, 63-64. Tmetocera, 54. ocellana, 54. Tolype 124. velleda, 124. Tomato-worm, 20. Tortricide, 47, 51, 52, 56-57, 148. Tortricoidea, 28, 29, 31, 44, 45, 48, 49, 51-58, 59, 147. Toxophora, 391. virgata, 390, 393. Trichocera, 234. spp., 234, 306. Trichocerine, 207, 208, 210, 234-235, 306-807. -Trichoptera, 20, 26, 34, 35, 148. Trichotaphe, 102. flavocostella, 103. Trillium declinatum, 5. Trimicra, 227. pilipes, 237. Triogma, 211. Tropea, 27, 145. luna, 146. Trupanea apivora, 383. Trypanisma, 103. prudens, 104. Trypetide, 166. Trypoxylon, 391. Tubifex rivulorum, 220. Turnips, 332. U Ula, 221, 224, 225. elegans, 225-226. Umbellifere, 316, 318. Uranotes, 84. melinus, 84. Utetheisa, 120. bella, 121. Uvularia grandiflora, 5. V Vanessa, 91. atalanta, 91. cardui, 91. huntera, 91. Vanessini, 90. Vertebrata, 441. Viburnum opulus, 5. Viola, 211. cucullata, 5. WwW Wasps, 375, 381, 391. White-grubs, 259, 352, 353, 354, 361, 370, 374, 384, 385, 388, 389, 391. INDEX 609 Willow, 225. Winter-gnats, 234. Wireworms, 397. Worms, 217. x Xanthotype, 129. erocataria, 131. Xiphura, 192, 194-195. fumipennis, 195. Xylocopa, 391. opifex, 394. virginica, 394. Xylomyia, 340-342, 346. americana, 341, 343, 344. aterrima, 341, 343. maculata, 340. pallidifemur, 341, 343-344. pallipes, 341, 342-343. parens, 341, 343. tenthredinoides, 342, 344. Xylomyiine, 317, 340-344. Xylophagide, 164, 175, 308, 309, 311, 313, 314, 341, 346-351, 352. Xylophagus, 347-348. abdominalis, 347, 348, 351. americanus, 343. decorus, 348. fasciatus, 348. gracilis, 348. longicornis, 348. lugens, 347, 348, 349-351. Xylophagus—Continued. persequus, 348. reflectens, 348. rufipes, 348. triangularis, 348. Xylorictide, 105. Y; Yponomeuta, 97. malinellus, 98. padellus, 98. Yponomeutide, 69, 71, 96, 97-98, 99, 100, 106. i Yponomeutoidea, 148. Ypsolophus, 102. citrifoliellus, 103. eupatoriellus, 103. 26, 32, 96-98, 147, Z Zabrachia, 335, 340. polita, 340. Zale, 118. calycanthata, 118. lunata, 118. Zelleria, 97. celastrusella, 98. Zeuzera, 41. pyrina, 41. Zeuzerine, 41. Zygoptera, 411-587. ’ i Ni \ J q 65 Ne , PS ON —~ Pe TE a3) ON UE 3 ~ D. =%, aN - 2, & w 1 # a> wr ~ x» => » ~ \S \ ‘ wi he es 7, ses SWS aN, WSOC wr xe See ee user Wy. , OF | oem wy a << ath iN = < cones Set a Se “ < SU) We Sm, | oo) “ x , a Ries ena ae eee Ss te ¢ B* \ oe PS a3 aL ss BAL ANS Yee SAS I a > Le hr Sey | ‘ Nat SW XO. Se VM wh Se EK Fy ee SK