XVI THE CHICAGO ACADEMY OF SCIENCES. 
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Gaatkaensis: (Wall) k.o.ckeka eo CRR eRe: eee 457 
Subeenus Potyertvitts MieGk: ck ceuseneereke oncamcn onenen 458 
Ge atahensis: Call) caccncc se hte OE OR er Oe 458 
Subgenus LEPTOLIMNAEA SwaAinsOn .........0ccceeeecceeeece 460 
Spurious and Unidentifiable» Species... ...:2:c5. chi. 2 .0nptin<iks able eile eee 462 
BDO SAD AY. | a0 xs cersraiw walede dares, seleia'e a place BbRalsN/s oRoleeR te ts totale eels ihe eee 468 
Description. Of Plates sq, tace. foe aye custo. sreysi svar vhclohataBeletewadobeteretetakeWs .ateheyuctel oe Taare Salil 
MARTE BA. 5g os cea never Snwvarrarar oka Fasarapavetoverade/lelcfler ssy'arsy otsteranstaledeye: sis R) or NeNe tole EPS ol rn ERC TCE 533 
MATES {b 5iisc asccnaracicn geawaneletevsislrcivon onctcad steven abe te fotate tate Raa catanomewe sete sowie fatto tc kodeiiowaelleraveyerelta ailaten et siete 534 
