IO16 NODULARIA 
related to N. dautsenbergi and possibly only an old state ot 
that species. The posterior end is somewhat drawn out and 
curved downward and the shel! is said to be wedge-shaped 
viewed from above. It is rather more elongated than the 
single specimen of dautzenbergi, which belongs in the National 
Museum. By a typographical error this name was spelled 
sobolus in the Synopsis. 
NCDULARIA VERBECKI ( Bottger). 
Shell subrhomboid, somewhat inflated, inequilateral, sub- 
solid; beaks only moderately full and high; anterior end nar- 
rowly rounded; base line curved; dorsal line curved ; posterior 
ridge full, double, ending at and below the median line in a 
biangulation; dorsal slope obliquely truncated; surface sculp- 
tured with coarse, irregular folds or undulations; the teeth 
compressed, curved. 
Length 47, height 26, diam. 18 mm. 
Length 41, height 25, diam. 15.5 mm. 
Singkarah Lake, Sumatra. 
Unio verbecki Bortcrr, Zool. Erg. Nied. Ost. Ind., IV, 1897, 
p. 80, pl. v, figs. 1, 2, 4, 5. 
Nodularia verbecki SIMPSON, Syn., 1900, p. 810. 
Contradens verbecki Haas, Conch. Cab., Unio, 1912, pl. 22, 
figs. 1-4. 
Von Martens credits this to Bottger manuscript. He does 
not give the color of the epidermis or nacre in his description. 
The species is close to N. dautzenbergi but is less inflated and 
does not have so strong a posterior ridge. It seems to be a 
little longer in proportion to its height. 
Section Rapratura Simpson. 
Radiatula Simpson, Syn., 1900, p. 820. 
Shell rather solid, triangular oval, with high beaks, which 
are but little inflated, not very full at post-base, and bluntly 
pointed behind, the beaks and entire surface covered with radi- 
ating, occasionally slightly zigzag or divaricate ridges, which 
are cut more or less into nodules or cancellations by concen- 
