THE LEECHES OF JAPAN. 387 
folds to which they belong (fig. 63, Pl. XXI), showing abso- 
lutely no trace of denticles or rudimentary plates. 
Nephridia seventeen pairs; first pair in the 15th, last pair 
in the 95th annulus. Four pairs in front of male orifice. 
Segmental papille in six dorsal and six ventral rows. 
The papillate annuli have the same number as in the preceding 
species. 
Colour.—The ground colour of the dorsal side is in the 
majority of cases a rich chrome green, sometimes exhibiting 
an exquisite shade of dark blue (fig. 28), more rarely inclining 
to the dull olive hue of fig. 39. There are five longitudinal 
stripes, one median and on each side two lateral. The median 
stripe is the broadest and most conspicuous, and is continuous 
from the first pair of eyes to the hind edge of the acetabulum. 
It is usually a brilliant chrome yellow, sometimes a gamboge 
yellow, or a bright golden yellow. It is bordered on each side 
by a narrow line of black, which is not sharply outlined. 
The lateral stripes are always narrower, generally duller ; 
and sometimes one or both of them (more frequently the inner 
one alone) are obsolete or obsolescent. As a rule, the lateral 
stripes, when present, are interrupted on every 5th annulus by 
the approximation of the black borders (figs. 33 and 37); and 
when absent are replaced by a black stripe, which represents 
the two borders united. These stripes are partially 
obliterated in fig. 28, wholly so in figs. 31 d, 32 d, and 34. 
The narrow margins are yellow, generally paler than the 
median stripe. 
The ventral side exhibits various shades of green and olive, 
more or less thickly sprinkled with black flecks. Alongside 
the yellow margins these flecks are so numerous that they 
might almost be said to form broad black borders. 
A specimen from Aomori, the only one found in this locality, 
was very dark green, with a bright median yellow stripe and 
black lateral stripes (fig. 31). 
Habitat.—Found in shallow pools in the rice fields around 
Tokio. Only one specimen found in Aomori, and none in 
Yezo. Comparatively rare. 
