32 Alf Wollebæk. No. 12 
that, as KorrLser had already discovered, the young do live for å 
time with the mother after they have left the shell and do not 
become independent, *pelagic”, at once like many other of the Carid 
genera, some of which belong even to the same family as Selero- 
erangon. The vitellus was actually not vet absorbed in the larvae 
thus found under the mother. 
The larvae mentioned by KorrserL in his work would seem 
to have belonged to a later stage than those found during the 
expedition of s/s *Michael Sars”. And as KozrseL moreover has 
only briefly mentioned the larvae and even then confines himself ehiefly 
to the appearance of their limbs, I have given å fuller and more 
explieit description of them in the Bergens Museum's Aarbog for 
1906. [fLe développement du genre Seleroerangon” (G. OQ. SARrs)|. 
The small larvae therein described had a total length of 11 mm. and 
were thus of the same size as the Sc. boreas depicted by G. Q. Sars 
in his Metamorphosis of Deeapods: the latter however, even though 
only of this size, has quite the appearance of the full-grown animal 
not merely in limbs but also in armature of carapace. In larvae 
of Sec. ferox of the same size the vitellus is not yet absorbed, and 
there is no indieation of armature on the carapace. As far as limbs 
were concerned these were, owing to the clinging habits of the 
larvae, of quite a different character from those of older animals 
living on the bottom. The difference is chiefly noticeable in the 
case of the pereiopods, and above all of the 4th and 5th pairs which 
are relatively the most stoutly developed and are furnished with large 
curved claws of a size and shape that show clear indications of the 
*parasitic” existence the small larvae pass through immediately after 
leaving the ovum. In the full-grown animal the elaws on the 
corresponding pereiopods are comparatively much shorter, and are 
narrower and only slightly eurved, constituting the true ambulatory 
limbs. With them the large highly-curved elaws of the clinging 
larvae have become shorter and straighter and are now more adapted 
to ambulation. In Pl. IX we have shown for purposes of comparison — 
5 pereiopods of å larva (fig. 5) and å corresponding number belonging 
to å full-grown animal (fig. 6). The limbs of the larva have of course 
been more enlarged than the others. 
The cehelae on the Ist pair of pereiopods act as prehensile 
organs in the full-grown animal (defensive organs?), whereas in 
the small larvae which live protected beneath the body of the mother 
they are not adapted for use. The digitus cannot be bent down and 
