PARRFA'SDV I I 29 



l^ength 33-35, height 21-24, diam. 15-14 mm." (Germain). 



Type locaHty, Bngala Island, Sesse Archipelago, Victoria- 

 Nyanza. 

 Unio rucUani var. bayoni Grrmain, Bull. Mtis. Hist. Nat., 



K>09. p. 275, pi. Ill, fig. 36. 



Parrcysia multicolor (von Martens). 



Shell oval rhomboid, moderately solid, inflated, inequilater- 

 al ; beaks rather full and high, with zigzag sculpture, which 

 does not extend far out over the disk ; anterior end rounded, 

 cut away somewhat below ; dorsal and basal outlines arcuate ; 

 dorsal slope obliquely subtruncate ; posterior ridge full, round- 

 ed, ending in a rounded point at the base ; epidermis shining, 

 dirty greenish-yellow or brownish-green with many narrow, 

 grass-green rays ; pseudocardinals thick, lamelliform with a 

 few strong furrows and notches ; laterals arched ; nacre rose 

 or purplish-red. 



Lake Victoria Nyanza. 

 Unio multicolor von Martens, Besch. Deuts. Ost-Af., 1897, 



p. 236, pi. VIT, fig. 4. 

 Parreysia multicolor Simpson, Syn,, 1900, p. 847. 



This species may be distinguished by the fine, bright rays 

 on the smoother part of the shell and the rich, purplish rose- 

 colored nacre. 



Parreysia ngesiana (von Martens). 



Shell subsolid, subinflated, rhomboid oval, inequilateral ; 

 beaks full and high, with strong, zigzag sculpture, which ex- 

 tends about half way over the disk with two radial rows of 

 tubercles, the rest of the surface nearly smooth ; anterior 

 end narrowly rounded ; base arcuate, full at the middle ; hinge 

 line curved ; dorsal slope obliquely truncate ; posterior ridge 

 rather high, narrowly roimded, ending just below the median 

 line in a blunt point ; epidermis light brown ; nacre silvery with 

 bluish or rose-red tints ; pseudocardinals lamellifomi, notched ; 

 laterals moderately arched. 



Length 33-35.5, height 24-24.5, diam. 16-17 mm. 



I^ake Albert Edward Nyanza. 



