no. 2065. THE CRUSTACEA EUPHAUSIACE A— HANSEN. 83 



Sur. 543. January 14, 1892. Lat. 35° 36' 30" N.; long. 124° 45' 

 30" W. Surface. 9.28 p. m. Surf. temp. 56°. 9 specimens. 



Sur. 542. January 14, 1892. Lat. 35° 31' N.; long. 124° 57' 30" 

 W. Surface. 7.19 p. m. Surf. temp. 56°. Many specimens. 



Sur. 541. January 14, 1892. Lat. 35° 25' 30" N.; long. 125° 09' 

 30" W. 5.17 p. m. 300-0 fathoms. 4 specimens. 



Sur. 540. January 14, 1892. Lat. 35° 19' 30" N.; long. 125° 21' 

 30" W. 1.58 p. m. 300-0 fathoms. 5 specimens. 



Description. — The front margin of the carapace, seen from above 

 (fig. 2a), in the main is transverse, yet having each half of the margin 

 distinctly concave, as the median half is produced a little forward, 

 forming a very short frontal plate, with the end rounded or angular, 

 but without any rostral process. The gastric area without median 

 keel; the lateral margin of the carapace with a well-developed den- 

 ticle a little before the middle. The eyes very large. 



Antennulse (figs. 2a-2d), with the first joint at the upper, inner 

 distal angle a little protruding and produced into a very small acute 

 triangle (fig. 2b), longer than broad, and directed forward somewhat 

 or slightly outward and much upward (figs. 2c-2d). Second and 

 third joints distinctly more slender than in E. lucens; second joint 

 above at the inner angle distally produced in a small or very small 

 spine; second joint longer than the third, which is thicker in the 

 male (fig. 2c) than in the female (fig. 2d). The dorsal carina, on third 

 joint, is moderately developed, with its front margin very oblique 

 and frequently a little concave beyond the upper angle. 



The copulatory organs (figs. 2e-2g) afford excellent characters 

 The terminal process (p 2 ) is moderately short and somewhat thick, 

 a little thicker than in E. lucens and E. frigida; the foot (/) is rather 

 long and the heel (h) somewhat short, with the end angular; seen 

 from behind (fig. 2f) the process has its most distal part a little 

 broader than beyond the middle, with the end seemingly flatly 

 rounded, but seen from the inner side (fig. 2g) the distal part of the 

 process shows itself to be much larger, but bent nearly angularly for- 

 ward, as a very oblong, distally obtuse, irregularly shaped plate. 

 The proximal process (p 3 ) is somewhat longer than the terminal (fig. 

 2f), but far from reaching its end. It has no secondary branch on 

 the outer side; its distal part is, seen from behind (fig. 2f), gradually 

 much compressed; seen from the inner side (fig. 2g) this part shows 

 itself to be a large, very oblong, distally rounded plate bent very 

 strongly backward, thus forming a nearly right angle with the 

 remainder of the process. On the distal margin of this plate, near 

 its base, an incision is seen, and a comparison with the structure in 

 E. frigida and E. lucens shows that the plate is the extremely elon- 

 gate posterior (or right) wing of the terminal expansion found in 

 these two species. The lateral process (p 4 ) is long, distally much 



