EUPHAUSIA MUTICA. 237 
the common form as the normal. And a similar instance in another species 
may be mentioned for comparison. Among a good number of Huphausia 
triacantha Holt and Tattersall secured by the Swedish Antarctic Expedition I 
have found a single specimen, an adult female, having the frontal plate much 
longer and very considerably broader and the rostrum much 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 localities, 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° 16’ E.; it is common in the East Indian Archipelago (‘‘Siboga’’). 
Ortmann’s types 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 surface, 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 mutica H. J. HaNseN, Bull. Mus. Océan. Monaco, no. 42, p. 14 (partim). 
1910. Euphausia mutica H. J. Hansen, Siboga-Exp., 37, p. 93, pl. 19, figs. la-ld. 
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. tosurface. 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. tosurface. 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. tosurface. 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. 
