EUPHAUSIA MTTTCA. 237 



the oonnnon form as the nonuaL And a simihir instance in another species 

 may be mentioned for comparison. Among a good luinihrr of Euphausia 

 triacaniha Holt and Tattersall secured by the Swedish Antarctic Expedition I 

 have found a single specimen, an adult female, ha\'ing the frontal plate much 

 longer and very considerably broader and the rostrum muc h shorter than in the 

 other specimens, excepting one which shows in a feeble degree the development 

 mentioned. 



The keel on the upper side of third antennular joint is moderately high, 

 rounded above on the highest point towards the distal end, and rarely with a 

 trace of the anterior incision found in the two preceding species. 



A single specimen (from Sta. 4713) is somewhat larger than all others, 



18 mm. long; many specimens measure 13-14 mm. in length, but the majority 



of the adults only 10-12 mm. 



* 



Distribution. — The species is unknown from the Atlantic. The Copen- 

 hagen Museum possesses specimens from a dozen locahties, viz. : — The Red Sea, 

 from Lat. 8° 1' S., long. 83° 51' E.; West of Cape Comorin; the Bay of Bengal, 

 and in the South Chinese Sea eastwards and northwards to Lat. 19° 14' N., 

 long. 116° IG' E.; it is common in the East Indian .Archipelago ("Siboga"). 

 Ortmann's tjrpes were taken at the Bindloe Island, Galapagos. The list shows 

 that the species is very common in the area explored in 1904-1905 excepting in 

 the southeastern part (from Sta. 4666 to Sta. 4705) and the southwestern part 

 (from Sta. 4733 to Sta. 4741) where it was entirely absent. 



The very long list of localities from the Agassiz Expedition shows that this 

 species has frequently been taken at the sm-face, sometimes even in large num- 

 bers. The Copenhagen material has certainly all been taken near the surface. 



15. Euphausia mutica H. J. Hansen. 



1905. Euphausia mulica H. J. Han.sen, Bull. Mus. Oc^an. Monaco, no. 42, p. 14 (partim). 

 1910. Euphausia mutica H. J. Hansen, Siboga-Exp., 37, p. 93, pi. 19, figs. la-Id. 



Sta. 4678. Dec. 6, 1904. Lat. 16° 31.2' S., long. 85° 3.8' W. Surface. 1 specimen. 



Sta. 4679. Dec. 7, 1904. Lat. 17° 26.4' S., long. 86° 46.5' W. 300 fms. to surface. 3 specimens. 



Sta. 4681. Dec. 8,1904. Lat. 18° 47.1' S., long. 89° 26' W. 300 fms. to surface. 21 specimens. 



Sta. 4682. Dec. 8,1904. Lat. 19° 7.6' S., long. 90° 10.6' W. Surface. 11 specimens. 



Sta. 4683. Dec. 9, 1904. Lat. 20° 2.4' S., long. 91° 52.5' W. 300 fms. to surface. 5 specimens. 



Sta. 4700. Dec. 25, 1904. Lat. 20° 28.8' S., long. 103° 26.3' W. Surface. 1 specimen. 



Sta. 4701. Dec. 26, 1904. Lat. 19° 11.5' S., long. 102° 24' W. 300 fms. to surface. 1 specimen. 



Sta. 4702. Dec. 26, 1904. Lat. 18° 39.5' S., long. 102° W. Surface. 2 specimens. 



Sta. 4703. Dec. 27, 1904. Lat. 17° 18.6' S., long. 100° 52.3' W. 300 fms. to surface. 2 specimens. 



Sta. 4704. Dec. 27, 1904. Lat. 16° 55.3' S., long. 100° 24.6' W. Surface. 28 specimens. 



Sta. 4705. Dec. 28, 1904. Lat. 15° 5.3' S., long. 99° 19' W. 300 fms. to surface. 8 specimens. 



Sta. 4706. Dec. 28, 1904. Lat. 14° 18.7' S., long. 98° 45.8' W. Surface. 13 specimens. 



Sta. 4723. Jan. 16, 1905. Lat. 10° 14.3' S., long. 107° 45.5' W. Surface. 2 specimens. 



