McGee and Call — Loss of Des Moines, Iowa. 



-Identical with base of No. 3. 

 -A band of fine, massive, homogeneous marl. 

 -A distinct line of separation, somewhat ferruginous. 

 —Loss, bluish for one-half foot from the summit, light 

 brownish-buff below, yielding a calcareous 



•yliudneal ferruginous concretions (most abund- 

 ant in the blue portion), loss-kindchen and tubelets, and 

 affording the following fauna : 

 Succinea obliqua Sar. Stenotrema monodon Rack. 



Succinea avara Say. Helicodiseus lineatus Say. 



L<mm>j,lnjm desidiosa Say. Mesodon clausa Say. 



,.-<.f l,. i,, .His Say. Jfrsodon undtilti icata Say. 



*Helicina occxdta Say. Pupa corticaria Say. 



JIi/it/iiHi (irborea Say. *Pupa muscontm Linn. 



Pttuh, xtriatella Anth. Pupa armifera Say. 



*Patula strigosa Gould. Strobila labyrinthica Say. 



* Vallonia pulchella Mull. 

 Though the section was not fresh at the time of exan 



tie obscured by weathering or talus and exhibited the 

 details very clearly. A syenite bowlder nearly three feet in 

 diameter was partially imbedded in the drift within a few feet 



rownish-yellow drift clay containing erratic pebbles and 

 bowlders up to four feet, yielding S,i,-.-h,m obliqua and 

 Lhn,n>i>In/*<i hmuilis toward the base, where it passes into 

 number 2 by both interstratification and insensible grada- 

 tion. About fifteen feet. 



ving fossds 

 "Helich 

 ' Vallonia pulchella I 



'inea obliqua Sar. *H<dicina occult" Say. 



'inea avara Say. * Vallon'm j>ufcb> [hi M all. 



>opht/8a hum Ms Say. Helicodiseus lineatus Say. 



Hijuliriu << irborea Say. " Mesodon clausa Say. 



Hyalina minitscula Bin. Mesodon multilineatu Say. 



*Patula strigosa Gould. * Mesodon thyroides (?) Say. 



Pi tula sfri'ftelta Anth. Strobila labyrinthica Say. 



/',itulo ultimata Sav. Conulus f ulcus Drap. 



*/V" muscontm Linn. Fe^V/o ou «ta Say. 



-ffypa corticaria Say. Carychium exiguum Say. 



The section was much obscured by a heavy talus and by 

 debris from near the surface at the time of examination. 



Like phenomena were observed in a number of sections not 

 here described ; and over the entire plateau lying between the 



