390 C. O. WHITMAN. 
Buccal Annuli=5th and 6th, united at the middle of 
ventral side, but distinct towards the margins. 
Post-buccal Annuli=/7th and 8th, fully united below. 
Genital Apertures.,—Male orifice near the middle of the 
34th annulus (4th of the 10th somite), three and a half annuli 
behind the fourth pair of nephridial pores. Female orifice in 
the 39th annulus (4th of the 11th somite). 
Clitellum.—Limits not determined. 
Anus behind the 104th annulus; sometimes cuts deeply 
into the hind edge of this annulus. 
Ocelli, five pairs, as in Hirudo. 
(sophagus has six folds. 
Maxille, three, on alternate folds, furnished with from ten 
to fifteen pairs of rudimentary denticular roots (fig. 45). In 
some cases the roots are united, the pair forming then a single 
transverse plate. In some individuals I found either no traces 
of rudiments or only a few scattered fragmentary remnants. 
Nephridia, seventeen pairs, beginning in the 15th and 
ending in the 95th annulus; located nearer the middle than 
the hind edge of the annulus. 
Segmental papille, in six dorsal and six ventral rows. 
The papillate annuli have the same number up to the 96th as 
in L. pigrum; the remaining three are the 100th, 102nd, and 
104th, instead of 101st, 103rd, and 105th. This is accounted 
for by the coalescence of the 2nd and 3rd annuli of the 23rd 
somite (fig. 53). These two annuli are still distinct in L. eden- 
tulum, but they are not so strongly divided as the following 
annuli. The papille are extremely small (figs. 41 and 42) as in 
the two preceding species. 
Colour.—The ground colour of the dorsal side is olive or 
olivaceous brown. There are five stripes, one median and four 
lateral. The broad median stripe is constant and often very 
conspicuous, owing to the metameric broadening of its black 
borders (fig. 41). This stripe is a pale olive or brownish olive, 
usually a lighter shade of the ground-colour itself. Its dark 
borders generally swell at regular intervals, as shown in 
Pl. XIX, fig. 41; but this peculiar pattern is often imperfectly 
