^- 



1 88 THE NAIADES OF MISSOURI 



spawning, at which time the mother buries her shell in the sand 

 up to the siphonal openings, the flaps are waved to and fro exposing 

 the ventral edges of the ovisacs through the branchial opening 

 while ever now and then sole-shaped conglutinates emerge from 

 the anal opening by convulsive jerks. With the eye spots showing 

 at the base and the fringed flaps rhythmatically waving one is 

 fascinated. Veniricosa is found to be typically bradytictic. The 

 geographic distribution for Missouri is wide; however, it is of 

 rare occurrence in the streams of North Missouri — never found in 

 Northwest Missouri. vSouth of the Missouri it is one of the com- 

 monest of shells. 



' Lampsilis ventricosa satura (Lea). 

 ("Plain Pocket Book.") 

 PL XXVIII, Figs. loy A—B. 



1852 — Unto satur Lea, Pr. Am. Phil. Soc, V., p. 252; Tr. Am. Phil. 



Soc, X. 1852, p. 205, pi. XXVII, fig. 19. 

 1900b — Lampsilis ventricosits satur (Lea) Simpson, Pr. U. S. Nat. Mus. 



XXII, p. 527. 



Animal Characters: — Identical in every way to the parent 

 species. 



Shell Characters : — Also identical to the species except in 

 its uni-coloration of epidermis which is rather a dark-brownish. 

 All shells collected by the writer for this State are also smaller 

 when mature. 



Sex Length Height Diameter Locality 



9 88 X 55 X 45mm — (Black R., Williamsville) 

 cf 75 X 54 X 42mm — (White R., HoUister) 



Miscellaneous Remarks: — This subspecies is only found 

 in the Southwest. For this State it is definitely reported by Mr. 

 Walker for the Black River., Popular Blufl". The writer collected 

 some of these forms of ventricosa from the same stream a few miles 

 north. The Black is a metropolis for veniricosa where it is found 

 in all forms, since this species is liable to intergrading — satura 

 being one of these intergradations. Yet its rayless character (like 

 that of capax) would make it worthy of a name. 



