apex of the telsou and hearing a few minute spinules on their inner margins ; dorsal 

 denticles usually in two pairs, the first aliout half-way towards, tin- second at the 

 base of, the sub-apical spines. 



Uropixh reaching to the level of the insertion of the sub-apical spines, (lie inner 

 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. 



Eupliiiuxin crystollorophios approaches most nearly among the species uf the 

 genus to E. 'x'nniti*, 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 se^mem.- 

 of the pleou, (3) in the absence of antenuular lobes and lappets. 



From E. spti-inli'iift. G. < >. Sars (E. Inci'iis, Hausen) the present species is dis- 

 tinguished by the greater length of the rostrum and by the absence of antenuular 

 lobes and leaflets, the types of E. splendens, G. 0. Sars, being possessed of a small 

 but distinct antenuular lobe. E. crystallorophios 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. 



Larva; of E. CRYSTALLOROPHIAS. 



The collection contains individuals in all stages of development from the 

 M<-liiiiniil>rms to the adult condition. 



The Calyptopi* larvze (Plate II., Fig. 8) first appear at the beginning of January 



and continue in the tow-nettings till nearly the end of February. The 1 1 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 .".<) mm. 



The Furi-Hiii stages (Plate II., Km. '.0 first appear during the last week of Fehruarv 

 and are abundant all through March. Thev cease after the (\\-^\ week in April. 

 The emaruinatioii of the apex of the telson is most marked during this stage and 

 serves readily to connect it with the early CW/// "'"/"''' larva-. The .-pine on the 

 lateral margin of the carapace is now well developed. The size of the Furciim larva- 

 Is from 4 - 5 mm. to 8 mm. 



The Cyrtopin larva- (Plate II.. Kig. LO) first occur about the last week in March, 

 and late post-larval stage- are still to be had at the beginning of August. The size of 

 this stage is from 8 to II mm. The rostral projection is now an acutely pointed 

 triangular plate, but the sides are still bin 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 -till lon^ ami plumose. Tliev 

 linallv become reduced to adult size when a length of I:; mm. i> readied. At this 



