56 PROF. G. 0. SARS ON THE COPEPODA [Jan. 12 
structure to that in C. cunningtoni, except that the spines on both 
rami of the 4th pair (fig. 154) are shorter and blunt at the tip. 
Last pair of legs (fig. 155) exhibiting the same rudimentary 
structure as in that species. 
Length of adult female 0°62 mm. 
Remarks.—Though closely allied to the preceding species, this 
form is at once distinguished by the less expanded anterior 
division of the body, the different shape of the cephalic segment, 
the more slender caudal sete, and finally by the shorter and 
thicker anterior antennee, which moreover are only 11-articulate, 
and have the sete of the anterior edge and upper face remarkably 
coarse. The specific name here proposed is derived from this 
last character. 
Occurrence.—Some few female specimens of this form were 
found in two of the samples from Tanganyika, the one taken 
28/9/04 at Mbete, south end of the lake, the other 13/10/04 at 
Sumbu, south- weston shore. 
25, CYCLOPS SEMISERRATUS, sp. n. (Plate XVIII. figs. 157- 
169.) 
Specific Characters. — Frmaur. Body (fig. 157) moderately 
slender, with the anterior division regularly oval in form, the 
greatest width occurring about in the middle. Cephalic segment 
lar ge and obtusely truncated in front. Last pedigerous segment 
with the lateral parts shghtly expanded and clothed w ith fine 
hairs. Urosome somewhat exceeding half the length of the 
anterior division; genital segment “comparatively caltont and 
distinctly dilated ‘at the base, carrying on each side a slender 
bristle (see fig. 167). Caudal rami (fig. 169) long and slender, 
considerably exceeding in length the last three segments com- 
bined, and of narrow linear form, slightly widening at the tip; 
outer edge armed for about half its length with a row of very 
small denticles, seta of this edge small and attached close to the 
end somewhat dorsally, innermost apical seta only shightly longer 
and much thinner than the outermost ; middle sete rather slender 
with the cilia of uniform appearance throughout, the inner one 
exceeding the outer by rather more than one-thir d of its length 
and abruptly bent outwards at the middle, Anterior antenne 
(fig. 158) comparatively slender, considerably exceeding the 
cephalic segment in length, and composed of 12 articulations. 
Posterior antenne (fig. 159) of moderate length, and having the 
seta of the basal joint well developed. Oral parts (figs. 160-163) 
and natatory legs (figs. 164-166) built on the same type as in 
C. serrulatus Fischer. Last pair of legs (figs. 167, 168) as in that 
Species, each composed of a single small, somewhat lamelliform 
joint, trilobate at the end and carrying two slender bristles and 
at the inner corner a ciliated spine, the latter, however, much 
smaller than in C. serrulatus. Ovisacs regulaxly oval in form and 
only very slightly divergent. 
Length of adult female 0:86 mm. 
