CONTENTS 
PAGE 
PI SRORMmOMIHCESTECIOS Seay ec anton 2 tine yams coal oS ole cress sratahecal cal orataoaea ee oon oa es 561 
Distribution and range in Ithaca and vicinity...............0 00. e ccc eee 561 
ehysicaleceavures:olesalt POOlS-csren cian al ie eckson cic ee ees ube 563 
Sle co.cc oad ARES ee oe Ios eee AR RR a ee Me A At aah oe eee 563 
Wie Lenape sense cer eis NPCS en Beanie, Ree Re ate Eid ok St oe 563 
DinlaptcatecontentiOlsalt: POOR s, <6. < Giatese ss renee i 565 
Life history........ #00 0 ai SOOO Gan Ome ee SU cee coche ke, PED TER eGR ade op ee 567 
TINS: LEIA. oc 6 26-0) Hie eer ere i i ere Fie hese cnc ee eee 567 
NUGTTEI NG) CRY 6 & So oe SIRO eee I eee Ae ee ae ON Be peer 567 
Bxtermalestructures: ne: ois scone se Se oe or ee ee 567 
Generalefeaturessnssi eee ee eee 567 
Wbhewintegumentss. sc Nae see Seen Oe Bas RR a ieee LN ede 568 
Phe RAPE agesn tice: Mewes ice teren eee ceric solic tn nL rence gm Toate 568 
AMNLEENAIEStRUCL ULES ar meer fey Bin, Mates atte patient em means ee ae eRe 569 
pluhegtrachealisy stem ters. wc sore cai Sie ee Ee ee 569 
PERNT V.OUSISY SLE ter pian ope ie oo eee Re eee eee 572 
pihesmuscularisysStemman swe ccrcincer hem ees aoe eee 573 
pRhegalimentaryasystem core. 2c ene cies era dela eee eto eee 575 
wthemvascularisystemien sacg--s conte ees oe ok imei nr ee 577 
uihe;reproductiversystems.\5.= 2.45.65. oes ace ec is ee oe 578 
hhepimacinaltdiskstee acct tin eee heme eco a weer eet ny caer a 578 
(GERD. 6.a-c-0 nse Behe Cope Die SMAI rio fierce eear co a SP ae 579 
Wioltingmpwetre eer eenttct ns dapsone eager s Oe she RE ae oes 579 
TSEDIED 5 6 a1 0G Bis Rents RE ER RO ene Stat oe Ca Pe a ree apd 580 
Observations on growth in salt and fresh water......................-. 581 
TS EPID. 6 6:c:0:G Ba OSD ER Ee Me UTR Rete ET ite ena tw Tor a etree 582 
GO CONVO GOT PTE Sse Pake ee CATES Oe eer EE oe nee 582 
TREBO TINE, 5's a eles eee OG CER nS Bicitot eel Bei ne iairen Shine mu ent irre ee ore 584 
TERES PL evil OT ee eeceetm yer Steen Me aca = a caw coin. ce eh eB gly meen Sn in fa cae 586 
Preference for stagnant and shallow water........................--.- 588 
IBreferences OMSalls wate nc on fe on toa ree Os ees 589 
iHactorssiniuencin sha bits .<yo osha ees ea) eS oie ee eae 591 
PAIDSEN CER OMy alse vw tes Ee elroy Sieeee eee 591 
PETIOLATE es tetter to tec ete Te tee ws SHRI ay eect ra wees Oa IP eee EE 593 
1 LAS OV cae eR ER NEN a a ae Re cE Par 594 
ESIC CE GION sects Aeoicee ce sie bap cea cy) ep WREST ES 594 
GE VEL Yr ROT teh Oe econ STIS ETS ni MUI ES ub Tors nee enc etme phn 595 
Wechanicaleinjuryprcse eon eer Co ae Pea ge 596 
MEG TOWGED ao d:n.5 Gc SSeS a ea eae CT Satis eh cs crn oe Ares Tae naa me iy Paine 596 
upationsand sperchingshabithy. ceases oe ice oe a enero eircom ee 596 
ene theotgpupalgperiod tess. vps sista oo teva ane aah Seine Cy easy oe eons tacts 597 
FRELAONREOLCIUVITON MED biche cict vee sies Cie acr eire wee Case ere ep ee er ie oahoue cs 598 
Inkdifferent kinds of¢solutionss.,.te esa in eo oie rosie cee eines a: 598 
WINETIREXPOSCC NEON AIT prada penn Ausra tycueensysWerey ATA uae) oh AAS ret akc Siac 598 
HifleCtTOMeXCESSIVeMNCat nai rc Sale ees) ee eiOee See Ors G Ree Scien 598 
TENS SORTS! 55 ae ad coe aE ett a Ub evoke On ge PSEC tek Oe ee 599 
IDITPGRRS TO as o Wipto a0 etl Citi Cibts Bro GNIS DOLORES RO on Cra OMIT LOIEG Oot 599 
Hootandsteedin guna bitsy verses cicter cecie hey aersier eh oyey sich avayaieie oilaye alien shove vara coke lay ayeve 599 
