540 REV. T. R. U. STEBBING ON CRUSTACEANS [May 22, 



did, though it was on his part done in a somewhat tentative 

 manner. On the whole, the identification of the ' Challenger ' 

 specimens with Dana's E. splendens seems to rest on a rather 

 insecure foundation. 



A third form is described by Sars as without doubt the Euphausia 

 gracilis of Dana, a decision for which tliere is strong support in 

 the figure given by Dana of his single, somewhat damaged, spe- 

 cimen. Still, even here there is room for remark. Sars says : 

 " Antennular peduncle without any dorsal lappet, basal joiut 

 shorter than the other two taken together;" but Dana says: 

 " First joint of inner antennae sparingly produced and acute at 

 apex," and figures it as decidedly longer than the t\\o other taken 

 together. Sars says that the inner plate of the uropods is much 

 longer than the outer. Dana, in a detail-figure, represents the 

 outer fully as long as, if not slightly longer than, the inner. Dana 

 says: " Feet very slender, last three joints subequal, and together 

 but little shorter than preceding joint." As already intimated, 

 Dana carelessly speaks of these proportions as though they applied 

 to all the feet indiscriminately, instead of varying in each pair. 

 There is, however, reason to believe that he bases his statements 

 on the last (developed) pair. In his lateral view of the animal 

 the three terminal joints of the last leg appear in fact subequal, 

 but together much longer than the preceding joint. As there is 

 no detail-figure of the limb, there is no need to insist on the 

 inconsistency between the figure and the description. But in the 

 lateral view given by Sai's the last three joints of the undescribed 

 last leg are very unequal. Also the detail-figure of the gill of the 

 last (rudimentary) leg, which is given by both authors, may 

 possibly represent the same structure, but twins would never be 

 confused if they were as little alike as these two drawings. 



Of the large and splendid Euphausia superba Dana, Sars, like 

 Dana, had but a single specimen. The agreement between the 

 figures and between the two accounts where they touch one 

 another, though not absolute, is sufficient to make it probable that 

 both authors are treating of the same species. 



Next after the four forms originally included in the genus comes 

 Euphausia miilleri Claus, 1863, from Messina. In regard to this 

 it is curious and perplexing that, while Sars deems it unquestion- 

 ably identical with what he considers to be Euphausia pellucida 

 Dana, Claus himself declares that it stands nearest to, without 

 being the same as Dana's, Euphausia splendens. In one notable 

 particular it agrees better with jjelJucida, both of Sars and Dana, 

 than with the splendens of either of these authors — namely, judging 

 by the detail-figure, it has the inner branch of the uropods reaching 

 decidedly beyond the outer. Claus, however, in the text makes no 

 mention of this character. On the other hand, he distinguishes 

 his own species from spUwlens as being longer (16-18 mm.), as 

 having a longer rostral projection, and the sixth pleon-seginent 

 relatively much shorter. The two latter distinctions are not borne 

 out by his figure as compared with Dana's. From E. pellucida of 

 Sars one might sav tliat E. miilleri is distinguished by a shorter 

 [24] 



