SYSTEMATIC REPORT 49 



St. 2059. 30. iv. 37 (day). North-north-east of St Helena, 1900-1400 m., 1 <J, 50 mm. 



St. 2061. 1. v. 37 (day). North-east of Ascension L, 1900-1500 m., 1 juv. $, 30 mm. 



St. 2063. 2.v.37(day). North-east of Ascension I., 2 hauls: (1)600-0 m., 1 imm. $, 41 mm.; (ii) 1150-600 m., i juv. 



St. 2064. 3. v. 37 (day). North-north-east of Ascension I., 1600-1050 m., 1 juv. 30 mm. 



St. 2065. 4. v. 37 (day). N. of Ascension I., 1600-1400 m. 1 adult ?, 45 mm. 



St. 2066. 5. v. 37 (day). South of Sierra Leone, 1950-1550 m., 1 juv. 



Remarks. Dana's original description of E. australis is short and not at all precise and his figures 

 are small and lacking in detail. 



I have given on p. 47 the main characters by which E. australis may be distinguished from E. ungui- 

 culata and E. grimaldii, but it must be stressed that the antennal scale is one of the most useful guides 

 in the determination of the species. In australis it is relatively very broad, only twice as long as broad 

 and is shorter than in the other species, extending forward for only about one-seventh of its length 

 beyond the anterior margin of the antennular peduncle, while in unguiculata and grimaldii it is more 

 than twice as long as broad and extends beyond the antennular peduncle for more than one-fourth 

 of its length. The sexual dimorphism, shown in the sinuous curve of the outer margin of the scale in 

 the male only and in the relative size of the antennular peduncle, does not occur in the other species 

 (Fig. 4C). In some specimens of australis the dividing line between the cornea and the eyestalk is 

 somewhat oblique, but never to the same extent as in the other two species. The specimens are very 

 fragile; the eyes in particular are very liable to distortion and in a surprising number of individuals 

 the cornea and distal end of the eyestalk are actually invaginated. 



The antennular peduncle is much more robust than in unguiculata and its third segment is arti- 

 culated very obliquely with the second. The inner margin of this segment is considerably longer than 

 the distal margin and is produced at its distal end into a strong setiferous lobe, as in grimaldii. 



The armature of the telson in the great majority of the specimens which I have here referred to 

 australis is shown in Fig. 4D, and resembles that of unguiculata in having a large number of spines in 

 the space between the distal large marginal spine and the apical spine. There are, however, some few 

 specimens which agree with australis in all other points but have these spines arranged more as in 

 grimaldii. 



Distribution. This species is, like unguiculata and grimaldii, a bathypelagic form, widely distributed 

 in nearly all the oceans of the world. It was first recorded from the Antarctic and was for a long time 

 regarded as essentially a southern form, but it has now been recorded, either as australis or as major, 

 from all the oceans of the world except the North Atlantic, the Arctic Ocean and the Mediterranean. 

 It has most frequently been recorded from the tropical and sub-tropical waters of the Atlantic and 

 Pacific, but also as far north as the Behring Sea, the coasts of Japan and the coasts of California 

 (Ortmann, 1906), and as far south as Graham Land and the Ice Edge in the Bellingshausen Sea. 



Of the thirty-two stations at which it occurs in the Discovery Collection, ten are in the South 

 Atlantic or the Antarctic, fifteen are in the tropical waters of the Atlantic (one of them in the West 

 Atlantic off Pernambuco) and four from the Atlantic near Cape Town. Three stations occur in the 

 Indian Ocean, off Madagascar. The greatest depth at which it was captured in this collection was 

 between 2480 m. and 2580 m. at station 101 and the least at station 2063 between 600 m. and the 

 surface. It has been recorded in very great depths in the western Pacific and was taken by ' Dana ' 

 at depths of over 6000 m. to the west of New Guinea. 



