78 
The bifurcate rostrum and the incomplete segmentation of the swimming feet, indicate 
that the ‘Siboga’ specimen belongs to the genus Vaddzviella. The specimen was evidently a 
female, and no doubt the rudimentary fifth pair of feet would disappear at the final ecdysis. 
2. Valdiviella > brevicornis Sars. Plate XXII, fig. 27—35. 
Valdiviella brevicornis Sars, 1905 (a), p. 17. 
A single male specimen belonging to the genus Vaddiveel/a, and doubtfully included 
under Sars’ species Valdiviella brevicornis, was obtained from the plankton collected with the 
HENSEN vertical net at Station 230, 2000 metres to the surface. 
The rostrum is small and distinctly bifurcate. The fourth and fifth thoracic segments are 
completely fused. The posterior margins of the last thoracic segment are narrowly rounded. 
The antennules are twenty-three-jointed and are well furnished with sensory organs. 
The antennae, mandibles, maxillae and maxillipedes are of the normal male Paraeuchaeta 
type. The mandibles have no toothed biting edge. The maxillae and maxillipedes are much reduced. 
The exopodite of the first pair of feet is distinctly three-jointed. Each joint is furnished 
with an outer-edge spine. 
The exopodites and endopodites of the second, third and fourth pairs of swimming feet 
are similar to those of Valdiwiella gigas. 
The fifth pair of feet is well developed and prehensile. The basiopodite is two-jointed. 
The second joint of the right basiopodite is much inflated at its proximal end. The distal 
portion of the joint is long and narrow. The joints of the basiopodite of the left foot are 
moderately long and cylindrical. The exopodite of the right foot is apparently only one-jointed. 
The joint is moderately long and has a lamelliform apex. The exopodite of the left foot is 
composed of three, short, subequal joints. The last joint is spiniform. The endopodites are 
one-jointed. The right endopodite is long and slender with a distinctly inflated apex. The +igcht 
endopodite is very short and is somewhat club-shaped. 
The abdomen is composed of five segments. The first, second, third and fourth segments 
are all of about equal length. The fifth segment is very small. 
Length — 5 mm. 
The specimen is clearly a Valdiviella by its bifurcate rostrum and by the incomplete 
segmentation of the second, third and fourth pairs of feet. It is not unusual to find the exopodite 
of the first pair of feet of the males of some of the Calanoids to be slightly different in the 
jointing from the females. From its size, the specimen may be the male of Sars’ Valdiviella 
brevicornis, but as no figures of Sars’ species have yet been published its relationship must 
be regarded as doubtful. The specimen is proportionally much smaller than either Vadldzviella 
- oligarthra Steuer, or Valdiviella insignis Farran. 
Genus Chiridiella Sars, 1907 (a). 
This genus was established by G. O. Sars in 1907 for an aberrant Calanoid form, 
which Farran suggests may lead a semi-parasitic mode of existence. Only the female is known, 
78 
left 
