/loll- 



MEMOIRS 



OF THE 



CAENEGIE MUSEUM 



Vol. VIII. No. 3. 



SOUTH AMERICAN NAIADES; A CONTRIBUTION TO THE 

 • KNOWLEDGE OF THE FRESHWATER MUSSELS 

 OF SOUTH AMERICA. 



By Dr. A. E. Ortmann. 



DMrim Of Biftvke 



(Plates XXXIV-XLVIII) 'Sscficnal Uhmty 



Introductory. 



During the expedition of the Carnegie Museum to central South America, 

 from 1907 to 1909, Mr. J. D. Haseman had as his prime object the collection of 

 Fishes (Haseman, 1911)'. At the request of the present writer he, however, took 

 particular pains to collect and preserve freshwater mussels. The result was one 

 of the finest and largest collections of South American Naiades ever secured. The 

 value of this collection is enhanced by the fact that a great numbei- of specimens 

 were preserved in alcoliol with the soft parts, and the study of their anatomy has 

 thus been made possible. Preliminary notes concerning the most important points 

 of structure have been previously published (Ortmann, 1911a), chiefly in order to 

 set forth the affinities of the South American forms with those of the restof the 

 world. Only a few typical forms were selected and discussed for this purpose. 

 Further examination of the material has revealed a number of additional and highly 

 interesting facts with regard to the anatomy, which throw light on the taxonomy 

 and i^hylogeny of this group. * 



' The references in parentheses are to the papers fouinl in tiie liilili(ia,rapliy at the end of tlii? 



4.51 



JAN 09 1987 



