

266 LIFE OF THE PLEISTOCENE 



ever, include also the Illinoian advance and the Sangamon interval, particularly 

 if the Iowan was not contemporaneous with the Illinoian. 



6. MISSOURI 



No records of aquatic life referable to the Yarmouth interval in Missouri 

 have been observed. Loess deposits are common along the Missouri and Miss- 

 issippi rivers, but the exact horizons from which the recorded fossils were 

 obtained are not stated. Many doubtless belong to a later period, and the pub- 

 lished lists are not available for the study of the Yarmouth fauna on account 

 of their ambiguity. A few of these are here recorded for the sake of complete- 

 ness. 



Swallow 74 and Hambach 75 both list a number or species from the loess of 

 the Missouri River, but no definite clue is given as to their being of post-Kansan 

 or later age. The species with their localities are indicated below. 76 The 

 acquatic species are probably not from true loess deposits. 



Mouth of Little Nemaha River. 

 Polygyra profunda Polygyra muitilineata Physa heterostropha 



Near mouth of Big Nemaha River. 



Polygyra muitilineata Galba elodes 



Pyramidida cronkkitei anthonfi Planorbis trivolvis 



Helicodiscus parallelus 



Half mile below Great Nemaha River. 

 Polygyra albolabris 



Near mouth of Wolf River. 

 Sphaerium species Physa plicata ( = heterostropha) 



Planorbis species Lymnaea, 5-6 species 



Segmentina armigera Pyramidida altemata 



Bellevue, Iron County. 

 Pyramidula altemata Galba fragilis ( = palustris) 



Bluff City Landing. 



Pyramidula altemata Succinea campestris 



Helicodiscus parallelus (=lineatus) Valvata tticarinata 



Vallonia pulchella (=gracilicosta?) Galba palmlris (=jragilis) 



Bifidaria armifcra " reflexa 



Circinaria concava " 5-6 species 



Polygyra thyroides Physa heterostropha (= plicata) 



profunda " gyrina 



Succinea ovalis (=obliqua) Planorbis trivalvis 



u Proc. Amer. Assoc. Ad. Sci., XI, pp. 21-39, 1858. 



'* Bull. Geol. Surv. Missouri, p. 82. 



78 The recent nomenclature is used in these lists. 



