8CH 1 7.0PO D.V 1 1 



.i|H'\ df the tclsoti and learing a few minute spinuK>s un their inner margins : <l-.r-Ml 

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

 base of, the sub-apical spines. 



Uropod* 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. 



Euphaiuia crystallorophins approaches most nearly among the species of the 

 genus to E. similif, G. 0. Sars, but differs ( 1 ) in the different shape of the rostral 

 projection, (2) in the shape of the cpimeral platen of the fourth and fifth segment* 

 of the plcon, (3) in the absence of antennular lobes and lappet*. 



From K. uplenden*, G. O. Sars (E. lucent, Hanson) the present specie* is dis- 

 tinguished by the greater length of the rostrum and by the a!>sence of antennular 

 loin-* and leaflets, the types of E. splendent, G. 0. Sars, In-ing possessed of a small 

 but distinct nntennular lobe. E. crystallorophiit* is an enormously abundant species 

 under the ice, some ten thousand specimens having l>een taken. None, however, 

 were met with in any other locality except Winter Quarters. 



Larvae of E. CRYSTALLOKOPHIAM. 



The collection contains individuals in all stages of development from the 

 Mttiniiin/iliuM to the adult condition. 



The Calyptopis Inrnr (Plate II., Fig. 8) first appear at the l>cginning of January 

 and continue in the tow-nettings till nearly the end of February. The IH..H! 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 Itegiuuing of the lateral spine of the carapace at 

 this stage. The largest Calyptopi* 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 Calyptopi* larva;. The spine on the 

 lateral margin of .the carapace is now well developed. The size of the FurcUia larva; 

 is from 4 5 mm. to 8 mm. 



The Cyrtopia larvae (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 1 1 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 1 1 mm. the telson assumes its adult shape, but the pair of spines 

 immediately anterior to the sub-apical spines arc still long and plumose. They 

 finally become reduced to adult size when a length of 13 mm. is reached. At this 



