bo 
~I 
TS 
ANNALS OF THE CARNEGIE MUSEUM. 
Unio pictorum (Linnzus) 1758. 
See also Ortmann, I9QIICc, p. 21. 
A large number of specimens, both males and females, are at hand, 
from various parts of Germany and Hungary, received from W. 
Israél. 
Fic. 11. Unio pictorum (Linneus). Male, from Saale River, Rudolstadt, 
Germany. (Carn. Mus., No. 61, 4,934.) 
Branchial opening separated from the anal by a complete diaphragm 
formed only by the gills. Anal opening closed above by the union 
of the margins of the mantle, forming a supra-anal; this mantle-con- 
nection is rather long, slightly longer than the anal, and about as long 
as the supra-anal. Inner edge of bran- 
chial with distinct papilla, that of the 
anal almost smooth, or with very minute 
crenulations. In front of the branchial 
the inner edge of the mantle is practically 
smooth. Palpi subfalciform, their pos- 
terior, margins united for about one-third 
of their length, or slightly more. 
Gills (corresponding to the shape of the 
shell) rather long and narrow, the inner 
the wider, chiefly so anteriorly. Anterior 
end of the gills as usual, that of the inner 
widely distant from the palpi. Outer 
lamina of outer gill entirely connected 
mis ria Mere pillsiok aisreriic with the mantle; inner lamina of inner 
female, same locality. gill free from abdominal sac, with excep- 
tion of its anterior end. 
Both gills with well-developed water-tubes and continuous septa. 
The septa of the inner gill of the male (see Plate XVIII, fig. 3) and 
