394 C. O. WHITMAN. 
than in any of the aquatic Leeches. In other Land Leeches 
they are also very strongly developed, though somewhat less 
prominent than in the Japanese species. In the Medicinal 
Leeches of Saigon, Singapore, Java, and Ceylon, they are 
much larger than in the European Hirudo, and their homo- 
logy with the eyes is here clear and unmistakable. 
The large Medicinal Leech of Saigon, which I shall call 
Hirudo saigonensis, is one of the most favorable objects 
for the study of the topographical relations of the segmental 
papille, and from it the accompanying diagram (fig. 1) has been 
constructed. The papillz are indicated by black dots, and the 
eyes by larger dots. On the 11th, the 14th, and the 19th 
rings there are eight dorsal papille, and on the 8th only six ; 
but here it is plain that the fifth pair of eyes (oc 5) occupy 
the places of two inner lateral papillze (7d). 
OC 
t 
Fic, 1.—Diagram of first seven Somites of Hirudo saigonensis.— 
The figures at left of diagram indicate the somites ; those at the right 
mark the first ring of each somite. oc 1—5. Five pairs of eyes. m. 
Median papille. 7.7. Inner lateral papille. 0. 7. Outer lateral papilla. 
mg. Marginal papille. 
