THE LEEOHES OF JAPAN. 379 
Buccal Annuli= 5th and 6th; distinct on the ventral 
side, but not so deeply divided as the following annuli. 
Post-buccal annuli = 7th and 8th, distinct below. 
Genital Apertures.—The male orifice is in the middle 
of the 82nd annulus (4th annulus of 10th somite); the 
female orifice lies between the 34th and 35th (lst and 
2nd of 11th somite), separated from the male by two and a 
half annuli. 
Clitellum embraces 9th, 10th, and 11th somites. 
Copulatory Glands. (‘¢ mucous glands,” Brooks).1—A 
quadrangular swollen area occupies nearly the median third of 
the 41st, 42nd, and 48rd annuli, on the ventral side. This 
area is divided into an anterior and a posterior half by a groove 
running along the middle line of the 42nd annulus, so that 
each half occupies the width of one annulus and a half (fig. 
57, Pl. XX). In each half is a row of six small oval areas, 
pale or flesh coloured, side by side; and in each of these two 
gland pores. Thus there are twenty-four pores in four parallel 
rows, as shown in the figure. The anterior row of oval areas 
stretch across the groove dividing the 41st and 42nd annuli ; 
the posterior row, across the groove dividing the 42nd and 43rd 
annuli; so that two rows of pores are associated with the 
42nd annulus, while the 41st and 43rd have each one row of 
pores. Six annuli intervene between the female orifice and the 
glandular area. 
Leidy? has suggested that the glands opening through these 
pores are “ provided for the adherence of individuals in sexual 
intercourse,” and their position favours this view. 
Ocelli.—Five pairs ; arranged precisely as in Hirudo. 
(isophagus=about one sixth of the length of the Leech. 
The number and arrangement of the folds, so far as I could 
learn from the specimen examined, agreed very nearly with 
Leidy’s description. 
Maxille.—tThree, large; armed with thirty-nine to forty- 
six acute and slightly curved deuticles. 
| V. K. Brooks, ‘Handbook of Invertebrate Zoology,’ Boston, 1882, 
2 Leidy, ‘Proc. Phil. Acad, Nat. Sci.,’ 1868, p. 230, 
