12 AURIVILLIUS, A NEW GENUS OF HARPACTICIDA. 
the limbs of the larva fully indicates that they are no swim- 
ming-organs, or very little so, but that, instead of this, 
they serve to attach the animal to the baleen-plates by 
their sharp claws. If the larva now described be compared 
with the figure of the larva of Dactylopus Strömii BAIRD, 
given by CLAus,”) it is found that there are also the same parts in 
its pairs of feet, although they appear in a quite different form. 
One specimen alone of the larva in this stage of develop- 
ment, among many hundreds that I have had occasion to observe, 
was a little more elongated behind, so that the body was as 
long as broad, but otherwise it completely resembled the 
larva described here. This specimen may possibly be a 
transition to the first Cyclops-stadium which differs other- 
wise very much from the Nauplius. 
The larva in the first Cyclops-stage (P1. IV. Fig. 1.) has 
five-jointed body, exclusive of the furca; first segment half 
as long as the whole body. Furca (Pl. IV. Fig..6.) having on 
each side two sete, the outer of these short and ciliated. 
Two tail-sete being the ordinary number in the other Harpac- 
ticida, the larva thus resembles them in this more than does the 
adult animal. Anterior antenne (P1. IV. Fig. 2.) consisting of 
three or four joints, the basal piece being indistincetly divided 
into two parts. Posterior antenne (Pl. IV. Fig. 3.) two-jointed, 
having three spines at the outer margin, but only two geni- 
culate sete at the apex, the third still having the indifferent 
form of a simple seta, shorter and stouter than both the 
others. Secondary branch of a strange appearance, being very 
short and broad, with irregular small tubercular processes on 
the sides and three setx at the apex. Mouth-organs and 
foot-jaws having already received a form differing in m»po 
essentials from that of the full-grown animal. First pair of 
feet, (P1. IV. Fig. 4.) having the basal part two-jointed, but 
the branches one-jointed and of almost equal length. Outer 
branch bearing two sharp claws and two fine, curved set; 
the inner having at the apex a very small spine and a lar- 
ger one, the apex of which is produced in a fine seta. One 
might say that this seta, as to its lower part, is transformed 
into.a claw, although it cannot act as such till the upper part 
has disappeared. Hence it seems that there is not so great 
+) CO. CLAUS. Die freilebenden Copepoden. Leipzig 1863. Tab. XVI fig. 2. 
