SCHIZOPODA. 1 1 



apex of the tcLsoii aud l)earing a few minute spinules on tlieir 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 crystalloropliias approaches most nearly among the species of the 

 genus to E. similis, G. 0. Sars, Ijut differs (l) in the different shape of the rostral 

 projection, (2) in the shape of the epimeral plates of the fourtli aud fifth segments 

 of the pleon, (3) in the absence of antennular lobes and lappets. 



From E. spleiidens, 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. sphmdem, G. 0. Sars, Ijeing possessed of a small 

 l)ut distinct antennular lobe. E. crystallorophias is an enormously abundant species 

 under the ice, some ten thousand specimens having been taken. None, however, 

 wore met with in any other locality except Winter Quarters. 



Larva) of E. crystallorophias. 



The collection contains individuals in all stages of development from the 

 Metanauplius to the adult condition. 



The Calyptopis larvae (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 jMarch. 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 Calyj^topis Iarva3. 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 larvje (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, l)ut 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 1 1 mm. the telson assumes its adult shape, but the pair of sj^ines 

 immediately anterioi' in the sul)-apical spines are still long and plumose. They 

 linallv become reduced to adult size when a leng;th of 13 mm. is reached. At this 



