﻿45^^ SOLENAIA 



burrowed in the mud. As Mycetopoda has a similar foot and 

 habit, the great savant concluded that the Asiatic and South 

 American forms were closely related and placed all of them in 

 d'(.)rbigny"s genus Mycctupns. 



Nearly all the shells 1 have seen of the Asiatic group have 

 feeble, elongated lateral teeth and this fact was so apparent 

 to Dr. Lea that he placed the .Inodonta soleniforniis of JJcn- 

 son in the genus Unio. Sometimes there are vestiges of 

 pseudocardinals in these forms as well as of laterals. The 

 true Mycetopodas are edentulous, or in some cases, when ex- 

 amined with a glass under a good light, the\ show traces of a 

 row' of denticles such as are exhibited by many members of 

 the family Mutelid<c. The animal of the South American forms 

 is mutelid. I know nothing of that of Solenaia beyond the 

 statement of Fischer regarding its greatly develo])e(l, mush- 

 room shaped foot and its burrowing habit. It is. I am satis- 

 fied, an unionoid animal and the fact that there is a decided 

 posterior pallial sinus to the shell leads me to believe that it 

 has two si])hons. 



The shell of Solenaia is of duller texture than that of 

 Mycetopoda, it is not so smooth and shining: wherever the 

 beaks have been preserved they are sculptured, whereas those 

 of Mycetopoda are smooth. 



KkY to SrFXIKS O'F S<1I.KX.\TA. 



Anterior end much produced and drawn out ai ihe anterior 

 base. 

 Shell almost squarely truncate behind. 5". emarginata^ 



Obliquely truncated behind, pointed below. 5. falcata. 



Anterior end scarcely or not at all produced. 

 Shell much elongated. 



Laterals partly develojied. posterior slope having a 



furrow. S. soleniformis. 



Laterals scarcely dcveloj)ed. epidermi.=; light colored. 



S. olcifora- 

 T^osterior ridge high. e])idermis dark. S. iridinea. 



Shell moderately elongated. 



Much wider behind. S. rk-ularis. 



Not greatly widened behind, beaks high and full. 



S. nigata. 

 Shell short, with low. sharp beaks. 5. triangularis.- 



