I* ..MUM.) 



, ,/, Milling, and 7'n//.//.//i<// f.>ni-nm Whitficld. but neither of 



th.-M- -p.vi.'- h.i> tin- ant.Ti.'r llopi -harply rMiiii-l."l .1- in 8, 'i'Jini< an. I J, OPMpWM, 



\\-\n- which we regard as a true Scwlln. seems to be more closely 



an.l X. l,,!,,it,'n<i.< Mian to N. MIH/;V.//-WI.V. The latter, judging 



snlfly fr.uii Hilling-' liu'iiiv- ami de-ci iption (.y.. - /'/. I, appears to diller from all the 

 specie- mentioned in having a UK ire attenuate apex and the whole anterior outline 

 ciincuve in a -id.- \ i.-\\. 



l'.,'Mde> tin- typical specimens of X. ,///////* we have before us six others from 

 tin- ::< -logical 1\ higher 'litamlM.mtc- ami KnM-pira lied-. In these the anterior 



cal ridge is less developed and the outline of the aperture more regularly 

 elliptical. The shell also seems to have been thinner and smoother externally. If 

 a Mil.unlinate name i- d.-in-d for this later form of the species it might l>e called 

 var. 



Formation antl Ir<tlitf. H\w\i Ulv.-r Kn-up. Clnn-lnnta Usl, and Tri'iiUm k'riiiip. Clitaiiit.nlUM 

 bed, ;,..- 1!, u.- <-.>unly, MlnnetwiU: I mil WykulT, HlnnctHita. 



UoM. Geolofflcal and Natural lli-i..ry Sur\.-> ..f MlnnenoU; K. <>. llri.-h; \V. II >.-..ileld. 



Mtuenm Kr,j> 



i I. A UHTI-A 

 I'l.ATK I.XXMI. 110. 10. 



OmctofMitw oMma SARDEKOM, 182, Bull. Minn. Acad. Nat. 8cL, vol. Ill, p. 338. 



Having seen no specimens which we could refer to this species, we reproduce 

 the original figure and description without expressing any positive opinion as to its 

 validity. So far as Mr. Sardeson's figure of the specimen upon which he founds the 

 species permits of judgment, it seems to us to be a Scenella in which the apex is 

 farther removed from the center and the apical angle wider than usual. 



/inal description: "Shell large, patelliform, or subconical, apex excentric, 

 apical angle 110 degrees. Aperture subcircular, about three times as wide as the 

 shell is high. Cast marked by four or five concentric furrows and by numerous 

 elevated radiating lint'-, from \'> to ~2^ in one centimeter." 



nation and ioeaKty. Black Uivcr Knuip. Uhinldlclya bed, Minneapolis. Minn.- 



* 



M H.I. A KAIMAI.I-. H. Sp. 

 ri.A I I I.M. I l..- 31 and 8. 



Shell large, depressed conical, hight slightly greater than one-third of the 



diameter; apex subcentral, obtuse; aperture almo-t circular, the margin apparently 



a little irregular though nearly hori/.ontal. Surface with di-tmct lines radiating 



from the apex, five or six in ' nun. These show through the outer parts of the 



