SCHIZOPODA. 
11 
apex of the tclson and bearing a few minute spinules on their inner margins ; dorsal 
denticles usually in two pairs, the first about half-way towards, the second at the 
base of, the sub-apical spines. 
Uropods reaching to the level of the insertion of the sub-apical spines, the outer 
very slightly longer than the inner, with a prominent denticle at its outer extremity. 
Length of the largest adult specimens of both sexes, 32 mm. 
Euphausia crystallorophias approaches most nearly among the species of the 
genus to E. similis, G. 0. Sars, but differs (1) in the different shape of the rostral 
projection, (2) in the shape of the epimeral plates of the fourth and fifth segments 
of the pleon, (3) in the absence of antennular lobes and lappets. 
From E. splendens, G. 0. Sars (E. lucens, Hansen) the present species is dis¬ 
tinguished by the greater length of the rostrum and by the absence of antennular 
lobes and leaflets, the types of E. splendens , G. 0. Sars, being possessed of a small 
but distinct antennular lobe. E. crystallorophias is an enormously abundant species 
under the ice, some ten thousand specimens having been taken. None, however, 
were met with in any other locality except Winter Quarters. 
Larvae of E. crystallorophias. 
The collection contains individuals in all stages of development from the 
Metanauplius to the adult condition. 
The Calyptopis larvse (Plate II., Fig. 8) first appear at the beginning of January 
and continue in the tow-nettings till nearly the end of February. The hood of the 
carapace is very obtusely pointed in front and has the margins quite smooth. There 
is no posterior median spine on the carapace, while the telson has the apical margin 
lightly emarginate. I can see the beginning of the lateral spine of the carapace at 
this stage. The largest Calyptopis larva measures 3 * 9 mm. 
The Furcilia stages (Plate II., Fig. 9) first appear during the last week of February 
and are abundant all through March. They cease. after the first week in April. 
The emargination of the apex of the telson is most marked during this stage and 
serves readily to connect it with the early Calyptopis larvse. The spine on the 
lateral margin of the carapace is now well developed. The size of the Furcilia larvse 
is from 4 • 5 mm. to 8 mm. 
The Cyrtopia larvse (Plate II., Fig. 10) first occur about the last week in March, 
and late post-larval stages are still to be had at the beginning of August. The size of 
this stage is from 8 to 11 mm. The rostral projection is now an acutely pointed 
triangular plate, but the sides are still but little concave. The final shape of the 
rostrum is not assumed till the animal is in all other respects like the adult. 
At a size of 11 mm. the telson assumes its adult shape, but the pair of spines 
immediately anterior to the sub-apical spines are still long and plumose. They 
finally become reduced to adult size when a length of 13 mm. is reached. At this 
