THE LEECHES OF JAPAN. 325 
teen pairs located in the following rings :—12, 17, 22, 27, 82, 
37, 42, 47, 52, 57, 62, 67, 72, 77, 82, 87, and 93. Their posi- 
tion is in the hind edge of the ring which precedes the ring 
bearing the segmental papille, as will be seen from fig. 7. 
The successive pairs are thus five rings apart, with the excep- 
tion of the last pair. The last pair le under the anterior of 
three peculiar lobe-like extensions of rings 93, 94, and 95. 
These marginal lobes, of which the middle pair are the 
smaller, are flattened, project obliquely backwards, and rest 
on the upper surface of the acetabulum. The area imme- 
diately surrounding them, as well as the lobes themselves, is 
paler than the rest of the body. 
Segmental Papillew.—There are twenty rings which, 
with the exception of the first and the last, project slightly 
beyond the others (figs. 3, 5, 6, 7) ; and as each (first and last 
excepted) bears six dorsal and six ventral papille, they may be 
called the papillate rmgs. The order of these rings, which 
begin with the 4th and end with the 93rd ring, is as follows :— 
4, 7,10, 13, 18, 23, 28, 33, 38, 48, 48, 53, 58, 63, 68, 73, 78, 
83, 88, 93. The papille are thus borne by every fifth ring 
except in the anterior portion of the body, where, owing to a 
reduction in the number of rings to a somite, they occur on 
every third ring. 
Colour.—The dorsal surface is divided into three longi- 
tudinal areas, a median and two lateral. The median area is 
always lighter in colour, and slightly wider than the lateral 
areas. Two dark brown stripes form the boundary lines 
between the median area and the lateral areas, and a third 
dark brown median stripe divides the median area into two 
halves. The median and wider stripe usually extends from 
between the first pair of eyes to the anus, and is of nearly 
uniform width throughout ; but in some cases (figs. 6 and 7) 
it vanishes, or nearly so, on the cephalic end and on a few of 
the posterior rigs. The lateral stripes usually vanish four to 
six rings behind the fifth pair of eyes, and seldom reach quite 
back to the posterior sucker. They are besides somewhat 
more irregular in outline than the median stripe. 
