1416 



P 



leuroumnaea 



Acella 



Pars21 



1867 Lininaea tenuicostata, Meek and Haydcn, (57b) Proa Acad Nat 



Sci. Philadelphia VIII, (1856), p. 278. 

 1861 Limnaea (Acella) tonuicostata, Meek and ffayden, (61a) Proc 



Acad. Nat. Sci. Philadelphia XII, (1800), p. 431. 



1807 Limnaea (Acella) tenuicostata, Conrad, (67a) Smithaonian Miac 



Coll. VII. No. (i, p, !). 

 1870 Limnaea (Fleurolimnaea) tenuicostata, Meck. (70a) Reporl U. S 



Gool. Survey of the Territ. IX. p. 584, tab. XXXXIV. 6« 



13a— c. 

 1877 Limnaea (Pleurolimnaea) tenuicostata, White, (77c) Bull. U. S. 



Geol. and Geogr. Survey of the Territ. III, p. 613. 

 1880 Liinnoa tenuicosta, S. A. Millor, (79a) Tho Joum of the Gincin- 



naty Soc. of Nat. Hist. III, 1880, p, 21. 

 1880 Limnaea (Plourolinmaea) tonuicostata, Whito. (80a) Tho Aino- 



rican Journ. of Sci. Ser. 3, vol. XX (CXX). p. 45. 

 L883 Limnaea tenuicostata. White, (83a) Report U. S. (lool Surve. 



III, (1882). p. 445. tab. XXIII, fig. 24. 

 1883 Limnaea (Pleuroliinuaoa) tonuicostata. White, (83c) L2th Ann. 



Roport U S. Geol. and Geogr. Survey of the Territ. I. p. s:; 

 1900 Limnaoa (Pleurolimnaea) tenuicostata, Graban and Shimer, 



(OOa) North American Lndex FossUs. tnvertebrates I i> 817 



Textfig. 1203 j. k. 

 1911 Pleurolimnaea tenuicostata, Baker, (lla) The Chicago 



Sci. Spooial Publ. No. .;, p. 96, tah. XVI. fig. 9—11. 

 Vorkom mc ii : l. Paleociin, Thanetien: Forl l^nicn 



F o r t U n i o n. 



Acad. 



sds; 



Zeitliche Verbreitung der tertiaren Species des Genus Acella 



SPECIES 



Pa" 



c 

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e 



eo< 



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8 



ea 



a 



a. 



:an 



a 



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Eoci 



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bon 



a 

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 u a 

 T2 o 



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a «3 



— 03 



in 



ia- 

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a 

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a 

 — 



Oli 



= 



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a 

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 t- 



gO( 



a 



4> 



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D- 



3 

 DS 



e 

 « 



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o- 



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o 

 « 



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3 



oa 



iociin 



(Vindo- 

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S J 



■~ a 



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2. ■ r 



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i 



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Pliocan 



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= a 



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o 5 » 

 £ 1 K 1 < 



Subgen. Acell;i 

 micronema 





__ 

































gracillima 













— 



— 











— 



— 





— 



- 



acuaria 











cosensis 













longa 







megarensis 



trans- 

 sylvanica 



^* 



Subgen. Pleu- 

 rolimnuea 



tenuicostata 





• 

















