1034 NODULARTA 
higher. Posterior muscular impressions faint, round; anterior 
large, deep; pallial impression visible the whole length of the 
shell, but not strong. 
Shell light, thin, fragile; epidermis of a deep brown and not 
very bright, more or less eroded towards the beaks; lines of 
growth quite fine and regular. Nacre bluish, slightly irides- 
cent, lead-color under the beaks. 
The young have the posterior region more expanded, owing 
to the ventral margin being more constricted in the middle, 
and the posterior extremity is nearer the median line. The 
shell is brighter and the lines of growth are very regular. 
Length 54, height at 18 mm. from the beaks 30, length of 
anterior region 14.5, of posterior region 41, diam. 17 mm.” 
(Germain). 
Type locality, Madagascar. 
Unio (Nodularia) geayi GERMAIN, Bull. Mus. Hist. Nat., 1911, 
DP: 137. Pl. T, MISS. AO, 7 
“The Unio geayi Germain has affinities on one hand with the 
species of India belonging to the subgenus Lamellidens and, 
on the other, with the African species of Nodularia. Compar- 
ed with the Lamellidens it reminds one, by its thin shell and 
hinge characters of Unio (Lamellidens) marginalis Lamarck 
from India and Cevlon; Unio (Lamellidens) thwaitesti Lea of 
Ceylon, etc. 
Compared with the African species, it is closely related 
to the Nodularie of the equatorial regions, (Unio (Nodularia) 
equatorialis Morelet; gaillardi Germain, etc.), by reason of 
thin, light shell, character of the nacre and reduction of the 
hinge.” 
NopULARIA HOREI (E. A. Smith). 
Shell subrhomboid, slightly inequilateral, rather thin, com- 
pressed; beaks full and high, with zigzag corrugations, and 
having radial plications in front of and behind them, the rest 
of the surface concentrically striate ; posterior ridge low, round- 
ed or semi-double, ending bluntly behind below the median 
line; base curved; anterior end rounded; dorsal slope almost 
