the; naiades of MISSOURI 



123 



its breeding season for August through to December, a sufficient 

 record to know that it is a long period breeder (bradytictic.) 



Genus, Strophitus Rafinesque. 



1820 — Strophitus Rafinesque, Ann. Gen. Sci. Phys. Brux., p. 316 

 1852 — Uniopsis Agassiz, Arch, fur Naturg., p. 49. 



(Type, Anodonta undulata Say). 



Animal Characters: — Branchial opening densely papillose; 

 anal papillose or crenulate; mantle connection between anal and 

 supra-anal not long and bordered by square, black spots; inner 

 gills larger, inner laminae free from, or united to, the viscera) 

 mass; palpi united antero-dorsal for most of their length; color 

 of soft parts variable but with the tendency to have certain parts 

 (such as foot, adductors, mantle edge at branchial opening) orange 

 in color; marsupium peculiar, consisting of ovisacs divided into 

 many compartments at right angles to the laminae; conglutinates 

 short, solid cords, (termed placeniulae by Ortmann.) 



Shell Characters: — Shell, subrhomboid to subelliptical, 

 subsolid, inflated, with low post-umbonai ridge; disk smooth; 

 beaks rather full, sculptured with rather heavy concentric bars 

 upcurved behind; epidermis rayed or rayless, polished; hinge 

 teeth mere rudiments, sometimes entirely absent. 



Because of the great specialization in marsupial structure, 

 the tendency of the inner lamina of the inner gill to become con- 

 nected to the visceral mass and also because of a more developed 

 hinge, this genus is the highest of the Anodontinae . It is represented 

 in this State only by 5. edentulus. 



Strophitus edentulus (Say.) 

 ("Squaw-Foot," "Creeper.") 

 PL XXIV, Figs. 8u A~D. 



1820 — Alasmodonta edentula Say, New Harm Diss., II, No. 22, p. 340. 



1888 Anodonta shafferiana B. W. Wright, Check List. 



1900b — Strophitus edentulus (Say) Simpson, U. S. Proc. Nat. Mus., 

 XXII, pp. 616-618. 



ANIMAL CHARACTERS. 



Nutritive Structures: — Branchial opening doubly papil- 

 lose; anal with inner edge crenulated, supra-anal moderately 



