9' 



sharp and even strong specific differences, proving that the fóur species are quite valid-, in 

 reality the males are very easy to determine by looking on the organs named with the aid of 

 a dissecting microscope magnifying 30 times. I have not yet examined my entire vast material 

 of the gióóa-group from the Atlantic and the Pacific, but the "Siboga" collection contains three 

 species, two of which I know from the North Atlantic, while of the real E. gibba G. O. Sars 

 I have only seen specimens from the Pacific. 



At present the genus Euphausia comprises the following 19 valid species hitherto 

 established : E. Krohnii Brandt (= E. Mulleri Claus + E. bidentata G. O. Sars), E. diomedece 

 Ortm., E. mutica H. J. H., E. recurva H. J. H., E. brevis H. J. H., E. superba Dana, G. O. Sars 

 (= E. Murrayi G. O. Sars + E. antarctica G. O. Sars + E. glacialis Hodgson -f- E. australis 

 Hodgson), E. similis G. O. Sars, E. crystallorophias Holt & Tatt., E. lucens H. J. H. (= E. 

 splendens Dana sens. G. O. Sars), E. tcnera H. J. H. (= E. gracilis Dana sens. Sars), E. Val- 

 Icntini Stebb., E. gibba G. O. Sars, E. pseudogibba Ortm., E. gibboides Ortm., E. Siboga H. J. H., 

 E. mucronata G. O. Sars, E. triacantha Holt & Tatt., E. spinifcra G. O. Sars and E. longi- 

 rostris H. J. H. The "Siboga" collection contains 8 species, 2 of which are new. 



a. Species with two pairs of lateral denticles on the carapace. 



6. Euphausia diomedece Ortm. PI. XIII, figs. 40 — 4e?. 



1894. Euphausia diomedece Ortmann, Buil. Mus. Comp. Zool. Vol. XXV, N" 8, p. 102, Plate, fig. 3. 

 1905. Eupliausia mutica H. J. Hansen, Buil. Mus. Océan. Monaco, N° 42, p. 14 (partim). 



Stat. 66. May 7/8. Bank between islands of Bahuluwang and Tambolungan, south of Saleyer. 



8 — 10 m. Plankton. Very large number of specimens, nearly all small or very 



small or larvae. 

 Stat. 75. June 8. Lat. 4°57'.4S., long. ii9°2'.8E. 18 m. HENSEN vertical net, with electric 



light, from 1 1 m. to surface. About 20 specimens, in all ages. 

 Stat. 99. June 28/29/30. Lat. 6° 7'. 5 N., long. 120° 26' E. Anchorage off North-Ubian. 16 — 23 m. 



Surface. 1 specimen. 

 Stat. ii 8. July 13. Lat. i° 38' N., long. I24°28'.2E. HENSEN vertical net, from 900 m. to 



surface. 14 specimens, in all ages. 

 Stat. 141. August 5. Lat. i°o'4S., long. I27°25'.3E. 1950 m. HENSEN vertical net, from 



1500 m. to surface. Very large number of specimens, in all ages. 

 Stat. 143. August 7. Lat. i°4'.5 S., long. 127 52'. 6 E. 1454 m. HENSEN vertical net, from 



1000 m. to surface. Many specimens, of various size. 

 Stat. 144. August 7/9. Anchorage North of Salomakiëe-(Damar-)island. 45 m. Townet. 4 specimens. 

 Stat. 146. August 9. Lat. o° 36' S., long. I28°32'.7E. 512 m. Surface. 26 somewhat small 



specimens. 

 Stat. 148. August 10. Lat. o°i7'.6S., long. 129 14'.5 E. 1855 m. Hexsen vertical net, from 



1000 m. to surface. Many specimens, more than half-grown to adult. 

 Stat. 177*. September 1. Lat. 2°3o'S., long. 129° 28' E. Townet. Many specimens, the majority 



very small. 

 Stat. 185. September 12. Lat. 3 20' S., long. I27°22'.9E. Manipa-strait. HENSEN vertical net, 



from 1536 m. to surface. Large number of specimens, of every size. 

 Stat. 189 1 . September 12. Lat. 2°22'S., long. [2Ó°46'E. Townet. Large number of specimens, 



of every size (many larvae). 

 Stat. 203. September 19. Lat. 3°32 : .5 S., long. I24°I5'.5 E. HENSEN vertical net, from 1500 m. 



to surface. Large number of specimens, of every size. 



