SCHIZOPODA. 11 



apex of the telson 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 



