SCHIZOPODA. 
15 
was therefore in error when he described the antennular peduncle of his E. splendens 
as “ more particularly distinguished by the total absence of any dorsal leaflet or lobe.” 
Moreover, it is apparent from what has already been written above in dealing with 
Euphausia vallentini that Sars confused at least two distinct species under the name 
E. splendens. It was subsequent to the publication of the preliminary notice of the 
‘ Discovery ’ collection that the present specimens came to hand. I therefore appealed 
to Dr. Caiman for further information with regard to the ‘ Challenger ’ species, and he 
very kindly sent me a sketch of the dorsal aspect of the anterior end of both types. 
From these sketches and Sars’ description in the ‘Challenger’ report I identified the 
‘ Discovery ’ specimens as Euphausia splendens, G. 0. Sars = E. lucens, H. J. Hansen. 
Wishing, however, to have confirmation of my identification, I submitted the 
specimens to Dr. Hansen, who at first was inclined to agree with me that they 
belonged to E. splendens, G. 0. Sars. I may, perhaps, be allowed to quote Dr. 
Hansen’s remarks. They read as follows : “ E. lucens (splendens ).—I have specimens 
from the southern Atlantic and the southern Pacific, and in all these the leaflet from 
first antennular joint is easily seen, triangular, but not acuminate, with the end often 
a little obtuse. In the material from the Swedish Antarctic expedition I have a large 
number of specimens which differ only from the Copenhagen specimens in the feature 
that the. antennular leaflet is extremely small (visible as a very small triangular 
distally obtuse plate when seen from in front . . . .) or rudimentary, but I find it 
necessary to consider this difference only as a variation ” (Hansen, in litt.). Then, 
after some remarks in which he noted that my specimens agree with the latter 
condition, he concludes by saying that he considers them to belong to the more 
Antarctic variety of E. lucens. In a later communication Dr. Hansen kindly informed 
me that, after an elaborate study of the copulatory organs on the first pleopods of the 
males of the genus Euphausia, he had found that these two varieties were readily 
distinguishable in the characters of the male pleopods, and that he proposed to 
consider them as two species. At the same time he was good enough to send me 
sketches of the first pleopods of both species for comparison with my own specimens. 
The largest ‘Discovery’ specimen is a male 18 mm. in length, and as far as I can 
judge, it appears to be quite adult. The copulatory apparatus on the first pleopods 
agrees exactly with the sketch which Dr. Hansen sent me of the same apparatus in his 
Antarctic form. It would therefore appear that these specimens belong to Hansen’s 
new Antarctic species. I have not attempted to give a detailed description with 
figures of this form, since it is quite evident that an accurate diagnosis can only be 
drawn up from a close study of this species and the true E. lucens side by side, and 
a careful comparison, character by character. There are no specimens of the true 
E. lucens in the ‘ Discovery ’ collection, so I leave the descriptions of the two species 
to Dr. Hansen, who has abundant material for the purpose. 
I may mention here that some specimens of an Euphausia (labelled E. splendens, 
G. 0. Sars) in the small collection of Antarctic Schizopods kindly lent me by Prof. 
