ilt 
some of them were broken, and I could therefore draw only their 
basal part. 
Fifth thoracic Segment. As mentioned above this segment 
constitutes the anterior part of the abdomen (fg. 15 and 16, a), 
being even a little narrower than its first segment (6). The legs 
(fig. 17) are rudimentary, each consisting of an oblique plate with 
one setåa on its outer edge and one very small ramus, which is 
obløng and rounded without any seta. This branch is certainly the 
outer one. 
Abdomen. It consists only of two segments and the cerci 
(figs. 15 and 16). The genital segment (6) is somewhat broader 
than long and considerably broader than thick; the genital apertures 
are lateral, oblique fissures. The second segment is a little more 
than half as long as the preceding one and a little more narrow; 
in my specimen its basal part is a little withdrawn in the genital 
segment, but it was impossible to discover any vestige of an inter- 
mediate segment, The cerci are slightly longer than broad, one of 
them with six setæ, of which four are short, the two others long; 
the longest seta is as long as the distance from the base of the 
second thoracic segment to the end of the cerci and one third longer 
than the other seta. On the left cercus only five setæ could be 
discovered, of which two are short, one is somewhat longer than 
the genital segment,- while the two long setæ had been broken off 
near the base. 
Measurements. The specimen examined measures about 0.54 mm. 
in length from the anterior end of the globular head to the tip of 
cerci, 0.44 mm. in breadth and 0.44 mm. in thickness; as shown in 
fig. 3 the ventral side of the head is bent strongly downwards, and 
the distance from the rostrum to the end of the cerci is slightly 
more than 0.3 mm. 
Ovisacs. In the specimen examined they measured about 
0.28 mm. in length and 0.16 mm. in breadth. It has been impossible 
to me to form a real conception of the number of the eggs, the 
