S02 C. O. WHITMAN. 
Anteriorly as well as posteriorly these pigment circles become 
obscure. They are just distinguishable on the 5th and 8th 
rings, a little more distinct on the 11th, and well defined from 
the 14th to the 94th. They are small on the 97th, faintly 
marked on the 99th, and reduced to the merest rudiments on 
the 101st. 
The median spots are arranged along each side the median 
yellow stripe, projecting somewhat into it and thus causing it 
to appear contracted or narrowed at regular intervals. The 
lateral spots are placed along the middle of the narrow dark 
brown stripes on either side (figs. 10, 18, and 21). The inner 
rows of lateral spots are directly in line with the eyes, and 
hence the most anterior of these spots are found on the 11th 
ring. 
Six rows of segmental papille occur also on the ventral side, 
and these are arranged as seen in fig. 13. Here we find two 
median rows, two lateral, and two marginal. The marginal 
rows are in the marginal yellow stripe, very near the edge; the 
lateral rows are a little farther removed from the median 
ventral line than the nephridial pores, and are about equidis- 
tant from the median and marginal rows. These papille are 
considerably smaller than those of the dorsal side, and on this 
account were for some time entirely overlooked. 
Colour.—This species exhibits great variability in colour 
and markings—so great that when the extremes are placed 
before us we find it easy to distinguish at least twenty or 
thirty different patterns. A ‘careful study of these forms has 
led me to the conclusion that they all belong to the same 
species, and that their differences are purely individual, and 
not such as to authorise even the distinction of “ varieties.” 
All the figures seen in P]. X VIII, except 15 and 16, which repre- 
sent individuals from Aomori, were drawn from living speci- 
mens obtained from streams and ponds in and around Tokio. 
Fig. 19 represents the more common colour and marking, and 
may be regarded as a typical example of the species; while 
figs. 14 and 18 show two very wide departures in respect to 
colour. 
