1909. | OF THE THIRD TANGANYIKA EXPEDITION. 33 
I. CALANOIDA. 
Of this division five species have been found in the collection, 
all of which belong to a single genus 
Genus Diapromus Westwood, 
Of this genus, as is well known, a very great number of species 
have been described, chiefly distributed in the lakes of the 
northern hemisphere. South of the equator the genus Loeckella 
seems to replace Diaptomus, only a very limited number of species 
of the latter genus having hitherto been recorded, viz., 2 from 
Victoria Nyanza, 2 from “the Cape Colony, 2 from Australia, 
and 6 from South America. Of the five species here recorded, 
two have been previously, though rather imperfectly, described, 
whereas the other three species are new to science. I give below 
short diagnoses of all the five species, and on the accompanying 
plates car refully- drawn. habitus- and detail- figures of each. 
1, DIAPTOMUS GALEBOIDES, nom. nov. (Plate VI. figs. 1-8.) 
Syn.: Diaptomus galebi Mrazek (not Barrois). 
Specific Characters.—Frmaur. Body (figs. 1 & 2) moderately 
slender, with the anterior division oblong in form, slightly 
narrowed both in front and behind, the greatest width occurring 
anterior to the middle. Last segment of metasome not defined 
from the preceding one, except by a very slight notch on each 
side, lateral corners scarcely at all projecting, nearly rectangular, 
with a very small and delicate mucroat the tip (see figs. 3 & 4) ; 
inner part rounded off, without any mucro. Urosome (fig. 3) 
almost quite symmetrical, with the genital segment only very 
slightly dilated in front, and carrying on each side an extremely 
small and delicate, hair-like point. Last two segments imper- 
fectly defined, and combined about half the length of the genital 
segment. Caudal rami comparatively short, with the marginal 
sete of quite normal appearance. Anterior antenne slender and 
elongated, when reflexed exceeding the body by the last 2 or 3 
joints (see fig. 2). Last pair of legs (fig. 5) with the inner 
ramus quite short, not attaining half the length of the proximal 
joint of the outer ; claw of the latter ramus of moderate size and 
finely ciliated inside; ; terminal joint only faintly defined at the 
base; inner apical seta extending beyond the tip of the claw. 
Ovisac (see fig. 1) comparatively small, and containing, as a rule, 
only four ova arranged regularly in pairs. 
Matz (fig. 6) somewhat smaller than female and of more slender 
form. Last segment of metasome with the lateral corners simple, 
scarcely produced behind. Urosome narrow cylindric in form, 
5-articulate. Right anterior antenna with the projection of the 
antepenultimate joint (see fig. 7) very small, not nearly attain- 
ing half the length of the penultimate joint, and scarcely at 
all curved at the tip; last jomt without any hook at the end. 
Last pair of legs (fig. 8) somewhat resembling in structure those 
Proc. Zoou. Soc.—1909, No. ITT. 3 
