Figs. 3l and 32. 
31. 
32. 
Figs. 33 and 34. 
Figs. 35 to 37. 
35 and 36. 
37. 
Fig. 38. 
Fig. 39. 
Figs. 40 and 41. 
Figs. 42 and 43. 
42. 
43. 
Figs. 44 and 45. 
Figs. 46 and 47. 
PLATH XXXVI.—Oontinued. 
PSILOCONCHA- MINNESOTENSIS, Ms/SP>s.c ot ove.c's sicieiajs </e-sfoie wlslelore sicialasctaictefelele clecstelosie/-Ieia ie 
The right side of a cast of thefinterior, which has been shortened by pressure no 
less than is indicated by the outline restorations. 
Dorsal outlines of same. Middle Galena, near Pleasant Grove, Minnesota. 
HIN DODESMAMC UNDA UNTs 21 SPs ees c: srctersicinyals wtelialal er ofeverere| piciaeialolcicdelercleteseiet shalalalafniel setae siete 
Dorsai and lateral views of an excellent cast of the interior. Middle Galena, 
near Wykoff, Minnesota. 
END ODESITAl COMPRESSUM (INS Pisis'o'sie oz 07s osoiw arstoia,ajeiefaier asia fe oiviniotel <daaeetstelateleisieveieleyeiere 
Dorsal and lateral views of a cast of a left valve. Middle Galena. near Wykoff, 
Minnesota. 
Sectional view across the shell a short distance behind the beaks, showing the 
inbending of the hinge plate. 
ENDODESMAN UND OSUM EIS iS Die civecs cise crcitininversysicice etele dversinieieie scierohe oLetehe totale elalcisiciaiejaaie 
Cast of the interior of both valves. ‘‘Upper Buff” beds of the Trenton formation, 
near Beloit, Wisconsin. Geol. Sur. Mus. Reg. No. 8344. 
CUNEANGYACTR UNG ATA SINGS IN aicle wis iolnistolere aelaletelejo\niate ei olaTerotetalereisiayeloharapsIeve(ro etal tensteteysralar 
Cast of the interior of a right valve. Middle Galena, near Wykoff, Minnesota. 
CUNEAMY-AT OBLONG Abney SP cietieierctacietaclactotsielsicie sisermouaisiele alt iereieloteiemsisinctete ataieterstatalsterats 
Lateral and dorsal views of the specimen described. The imperfect posterior 
end is restored in the figure. Upper Galena, Dixon, Illinois. 
SPHENOLEU MG PAR AT MCT DMs olla (SP. ime cioteie vials cle taiztaretesereieratelsimierekeiers teeters cieyafohaiel one toreianerelarate 
Cast of the interior of a right valve, imperfect at the anterior end, but otherwise 
in an excellent state of preservation. 
Cardinal view of the same, with the left valve restored in outline. 
Blue” beds of the Trenton formation, Mineral Point, Wisconsin. 
Mus. Reg. No. 8346. 
SPHENOLIUMSTRIATUMs | SPiyess nies nieiciole eis crete cinysjerajahe| eels eleistelsjo<folels clsietwisja]oieteie(elteleials 
Lateral and dorsal views of a nearly complete cast of the interior. Middle 
Galena, Goodhue county, Minnesota. 
“Lower 
Geol. Sur. 
REY TIMYA SINUATA, 1 SP oiseec cc cece scenes cr edesccinsne vices ccesesse eres csasensccnss 
Lateral and dorsal views of an internal cast of a left valve. Middle Galena near 
Wykoff, Minnesota. 
529 
529 
624 
624 
619 
