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 <>f 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, II. J. Ilansen. 

 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. xj>I< //</< //*, G. 0. Sars. I may, perhaps, lie allowed to ijuote Dr. 

 Ilansen'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 Ilansen'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. />/<>//* 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 7v >;</> .-/'" (labelled E. xpli'ml, us, 

 G. 0. Sars) in the small collection of Antarctic Schizopods kindly lent me by Prof. 



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