WlTl KR-OBSIRVATIONS ON l.d-.SS IN AND ABOUT MUSCATINI.. 4.") 



SOME ADDITIONAL OBSERVATIONS ON THE 

 LCESS IN AND ABOUT MUSCATINi:. 



\:\. I'ROF F. M. \V! r-n.K 



Tho un<'Ous()li(lated material restiiia" on the drift in and 

 about Muscatine poss>es.se.s many of the rharaeter.s of the loess 

 and since it passes by insensil)le uradations into the latter it 

 seems rather to belong to the loess than to the drift. 



The lower ]i)ortion is generally most perfectly and beau- 

 tifully stratifi;'d, the strata consisting of sand, clay, and 

 occasloually some gravel, with small boulders of the granitic- 

 series, fragments of bituminous coal, etc. A very few cal- 

 careous concretions are found in t!ie stratifir'd basal l)eds and 

 at one point i^ood specimens of these concretions have 

 imbedded pebbles. In the less evidently stratifi.'d [jortions 

 abound several species of land s!i"lls and the eggs of one 

 species are found. But little saud and this of the finest grain 

 isfouud in the unstratifi'd higher portions. lu this have been 

 found the teeth and largely the bones of two examples of 

 liangifer caribou and the greater portion of the antler of the 

 same species most probably. Two or three species of fresh 

 water mollusks have been found in wh.it appears to l)e loess. 



THE PARVUS GROUP OF UNIONID/E, 



BY PROF. R. KLLi>\VORTH CALL 



This paper i^ave a resume of the known facts iu the geo- 

 graphical distribution of these small Um'os and proposed the 

 reduction of a number of forms to synonymy. The relation 

 of the assumed specifi-' differences to conditiiuis clearly con- 

 nected with environment was pointed out and a somewhat 

 close relationship of forms hitherto supposed to be very 

 distiu'.-t was evid.'nced by the specimens exhil>ited. The dis- 



[Pk.k. I. A. S.. 1SS7-9.] 45 [February la. 1890.I 



