1909.] OF THE THIRD TANGANYIKA EXPEDITION. 35 
and elongated, when reflexed exceeding the body by the last three 
joints. Last pair of legs (fig. 12) rather short and stout; inner 
ramus about half the length of the proximal joimt of the outer ; 
claw of the latter ramus smooth inside ; terminal joint very small, 
with the inner apical seta not extended beyond the tip of the 
claw. 
Mate (fig. 13) with the lateral corners of last segment of 
metasome produced backwards and each tipped with a well 
defined mucro, the right one more prominent than left. Uvro- 
some very slender and more or less turned to right side. Right 
anterior antenna (fig. 14) with the middle section rather dilated ; 
terminal section, as usual, composed of four joints, the ante- 
penultimate one produced at the end anteriorly to arather strong 
hook-like projection (fig. 15) considerably exceeding half the 
length of the penultimate jot. Last pai: of legs (fig. 16) rather 
strongly built ; right leg with the 2nd basal joint produced at the 
end, on the posterior face, to a short and broad, securiform plate 
projecting into three angular corners (fig. 17); inner ramus 
extremely small and rudimentary ; outer ramus with the proximal 
joint short and obtusely produced outside ; distal joint very large, 
oblong, pyriform in shape, and so attached that it forms nearly a 
right angle with the axis of the leg; scale-like projection of 
posterior face occurring just inside the lateral spine, the latter 
rather slender and attached close to the base; apical claw strong 
and much curved. Left leg of a similar structure to that in 
D. galeboides. 
Length of adult female 1°55 mm. 
Remarks.—In the general appearance, the distinctly developed 
mucros on the last segment of the metasome, and the con- 
spicuously asymmetrical urosome, this form much more resembles 
D. galebi than does the preceding species. Yetitis quite certainly 
distinct from both these species, as proved by the rather different 
structure of the last pair of legs, especially in the male. The 
somewhat mixed characters of this species have given rise to the 
specific name here proposed. 
Occurrence.—A single adult female and some few male speci- 
mens of this form were picked up from a sample taken 13/6/04 
in Anchorage Bay, southern end of Lake Nyasa. The sample 
contained a considerable quantity of a dark muddy deposit, and 
thus has apparently been taken from very shallow water. A few 
not fully adult. specimens of the same species occurred also in 
another sample taken 11/6/04 in that bay. 
3. DIAProMUS STUHLMANNI Mrazek. (Plate VIII. figs. 18-24.) 
Diaptomus stuhlmanni Mrazek, Die Copepoden Ost-Afrikas, 
p. 7, pl. iii. figs. 1-3, 6, 7. 
Specific Characters.—Frmaue. Body (figs. 18 & 19) compara- 
tively short and stout, with the anterior division somewhat 
dilated in front, the greatest width occurring across the cephalic 
segment. Last segment of metasome, as in the two preceding 
3% 
