3] 4 ORTMANN — DISTRIBUTION OF DECAPODS [Aprils, 



North American Geographic Development" {Amer. Jotirn. Sci., Vol. xlv, 



1893)- 

 Hill, R. T. " The Geological History of the Isthmus of Panama and Portions 



of Costa Rica" (Bu//. Mus. Harvard, Yo\. xxviii, 1898). 

 KoKEN, E, Die Vorwelt t*nd ihre Entwicklungsgesc/iichtey l?>g-^. 

 KossMAT, F. " Die Bedeutung der suedindischen Kreideformation fuer die 

 Beurteilung der geographischen Verhaeltnisse waehrend der spaeteren 

 Kreidezeit" {Jahrb. k. k. Geol. Reichanst., Vol. xliv, 1895). 

 Meddlicott, H. B,, and Blandford, W. T. A Manual of the Geology of 



India, Vol. i, 1879, 

 Neumayr, M. Erdgeschichte, 1890. 

 SUESS, E. Das Antlitz der Erde, Vol. i, 1883- 1885 5 Vol. ii, 1888. 



"Beitraege zur Stratigraphie Central- Asiens " {Denksckr. Akad. Wiss. 



Wien,Vo\. Ixi, 1894). 



In the following we shall endeavor to answer the questions : 

 What con7tections are suggested by the distribution of the freshwater 

 Decapods^ and Is there any other evidence, in the first place, of a 

 geological character to support them ? The solution of these ques- 

 tions will furnish us the key for the reconstruction of the old geo- 

 graphic conditions. 



If we recall the connections suggested by the distribution of the 

 freshwater Crustaceans, we can collect them in the following list : 



1. Connection of nortlieast Asia with 7iorthwest America across 

 Bering Sea (see pp. 290, "291, 295). 



2. Connection of east Asia with Australia (see pp. 295, 305). 



3. Connection of south Asia with Madagascar a?id Africa (see 

 pp. 295, 305, 306). 



4. Connection of New Zealand with Australia (see p. 295). 



5. Connection of Australia {resp. New Zealand^ with South 

 Ai7ierica (see p, 295). 



6. Connectioti of the West Lidies with Ce?itral, resp. South 

 America (see pp. 295, 309). 



7. Connection of South America witli Africa (see p. 310). 

 Other important questions arose out of the distributional facts, 



which may be classified under the following heads : 



8. General relations of North, Central and South America (see 

 pp. 295, 309). 



9. Relations of Africa to the rest of the world (see pp. 303, 304). 



10. Relations of Europe to Asia {and Africa) (see pp. 291, 



295. 304). 

 We shall take up these different items in the order here indi- 



