vi 
PAGE. 
IN yO PB S's. 'c10 crn ec eleie oie oie cieieiei s.c101n) olsinip inicio) sininisialensisieis lelria\cin\e)«|ejolsl= timninie Be 4 
TMABOSs 4 nie stores eisiece clalsicps sists ererara eeeasle pie etare tetera gee tetisets siete efstanatato ete 26 
Family PetaQlurtd 2... ccve ven cece cca cnee ence ses cen e cece snes cece eees 27 
Family ALSCHNIAE....00. coc 00a vet wens nese cone cece sone eces cot nicinoe aes0e 27 
Key to Genera... 2... 222. cece cone cee cone tone cece cers cons cane aerers 30 
Ibtty sie JegrriAdba HOpo ron pOlaeboa Ao Oncpdn nootsrncc sei Heos Coe yob9 Hook 30 
NES bese thee ener eeMnMne GRUB cad crabibcn bAtsanasdouumdnoqabSnoentct 656 33 
IDyosek{el vee WARN A BaeeMAHn Oberon OObabooa O00 6 9s anor edhe dodn Obovedecoo. 35 
Oy erence ocapaietain levels =Heretslaavatels felelsiofaiete atc tsretauieals top otetebtiehet iets) = keto tekae cateae 36 
Basizeschma: te lictea cesses pavlneesncteoeposseaye ater rene oiay fetes eta cach ea ere 38 
PO dE nee, Ha ee a Ga Ace oo anon doo qurcinmgacen iden sno ap syoo kN je 39 
Key: tOlmy Maps ie aie spsre wieetete wlryetr) a rmcete ene re tine fof vcle cn ote gkn oi) chad taeoS 40 
it qe ee ae IN RnR 26) Sin dcr orange MR e ne He ERO OOO ROG oc 46 
1h) (COVA LUCE ARADO AOU AD OI5 40 cone meOsdOccenaBsoareomagernooouL: 50 
Ne yGiite) CeOegdecanersvaacvac coodonssoneamacenesdeaseeedome sesuessh 52 
Drea OSisyztere seve te 1cse/ ayers teyerete tetedate meee matee esata eye te pete) tape tetee te Nolete ee Tela ee 52 
Ni gidlol eons Abdocano aso sbancoononsdese sonar adaadoatoaegansbed 70 53 
Noy AlE@enenenpcenoeuenan woo dosh on adapcotneobasnonodosesbesder laces 54 
Isdopdonja| Niewmrenosantos ondosnwosapochpogooSpgmovseccduacanseb one Boe, ys 
Diastatatomma and Herpetogomphus.............-..-.----.0-++ee0e 57 
AA fehl kiganosaguadoausay conc sot soo SDen ru cdAnaBdbeAaosoHIAGS 58 
LSEY tran ANA SnOSo BOE OUnne sohogundoDbasoouedany cogs ede aeabwIG - 60 
LEE held Nu ee EAE nom OiaeG gitid pemconoc ac Ududcancomcmageno Gan bocssc 62 
ID} Roh enloy-Kojono)UChAe soem nrAssAdgoorNcodadhodosGe 4” Aboonsnwnycnadosse 4 64 
Gon p Buss score ersinrevete sa) atcicen)s ele sreteratiintor stoke ate le tei Fase fe ister sietiets tye eteretat tee siete 65 
Key to) amy map ls p- reser erento misters ete neste eter eee eek erate 66 
Sto paamenonada donoosdd qcudcccnnbs ovsbduocodsenbosteenanndaoc: 68 
PET ih) ga PRG AO OSD OOO ED OA Onan TOD Ae AOR OTA DOE Os. go 
ARTICLE II._PLANKTON STUDIES. IV. THE PLANKTON OF 
THE ILLINOIS RIVER, 1894-1899, WITH INTRODUCTORY 
NOTES UPON THE HYDROGRAPHY OF THE ILLINOIS 
RIVER AND ITS BASIN. PART I. QUANTITATIVE INVES- PAGE 
TIGATIONS AND GENERAL RESULTS. BY C.A.KOFOID.... 95 629 
INTRODUCTION 
PNA aon Aso fpelAeicinnda eh sugc oni daoonagoddoon tbo otAnea Aes med HAN eS ne 96 
THE GEOLOGICAL AND HYDROGRAPHIC FEATURES OF THE ILLINOIS 
RIVER BASIN 
Somer Maca G aie. sah Gen einer Cone ROME o Rau ACNE 6 98-251 
TRE OMUCLOTY Vira seicteteie cx, aloe eat ee a TEE RUTH erectete oes cee 98 
LOC ALON. or5 ee Sr eis tases eee HR Re EL IEE ee BO Re eee feniete certo iere revere 99 
Geological Features of the Illinois River Bastn.... +... cece cece ce ccc renee 99 
FCT @ Via tL oi 5 :ch5.4 5 Sec kotare eas cto lee ote HAT one a elon oe eee emratetereisien cierer were terane 99 
GlacialsandivalleysD rite: cece rer ieee eieete etait ieee re een 100 
ING RAGES BEMA Dene np rmperand Goeswontiooooanod eb aTaDResaeseunSosasT 101 
Lite LUMO RAVER SY SLEML detain 20 eae ne ee ee err 102 
Length and area 
