MYCTOPHIDAE 321 



lower part of pectoral base, forming a straight line with the two PVO, which lie close 

 together and side by side. 5 PO (6 on one side in the ' Southern Cross' specimen), all 

 level. VLO much nearer pelvic fin than lateral line. 4 VO, all level. No SAO. AO 

 14-1 1^, the first 2 elevated, the remainder forming a more or less straight line, 4 behind 

 the last anal ray. Pre close together, second scarcely elevated. 



Described from three specimens, 18 to 55 mm. in length. 



Hab. South Atlantic; Antarctic (Victoria Land). 



The types of this species, 22 and 60 mm. in length, were in poor condition, and the 

 SAO photophores were described as missing, but their absence in all the specimens 

 described above suggests that this is the normal condition. It is possible, however, that 

 the so-called anterior AO, which are elevated above the level of the remainder, should 

 be regarded as belonging to the SAO series. 



Myctophum tenisoni, n.sp. 



St. 36. 18. iii. 26. 38 miles N 39° E of Jason Light, South Georgia, i m. tow-net, horizontal, 

 90 (-0) m. : I specimen, 65 mm. 



St. 44. 3. iv. 26. 32 miles N 51° E of Jason Light, South Georgia, i m. tow-net, horizontal, 

 170 (-0) m. : 2 specimens, 64-69 mm. 



St. 65. 22. V. 26. 48° 18' 00" S, 53° 09' 00" W. 2 m. tow-net, horizontal, 120 (-0) m. : i specimen, 

 32 mm. 



St. 72. I. vi. 26. 41° 43' 20" S, 42° 20' 40" W. 4I m. net, horizontal, 2000 (-0) m. : 3 specimens, 

 36-46 mm. 



St. 107. 4. xi. 26. 45° 03' 00" S, 17° 03' 00" E. 4J m. net, horizontal, 850-950 m. : i specimen, 

 50 mm. 



St. 109. 5. xi. 26. 46° 25' 00" S, 15° 13' 00" E. I m. tow-net, horizontal, 96 m.: 3 specimens, 

 42-47 mm. (Largest selected as the holotype.) 



St. 114. 12. xi. 26. 52° 25' 00" S, 9° 50' 00" E. 4^ m. net, horizontal, 650-700 (-0) m. : 2 

 specimens, 43-60 mm. 



St. 217. 18. iv. 27. Drake Strait, 58° 27' 30" S, 67° 55' 00" W. i m. tow-net, horizontal, 77 m. : 

 2 specimens, 35-36 mm. 



St. 239. 2. vi. 27. 46° 56' 00" S, 46° 03' 00" W. 4I m. net, horizontal, 1050-1350 (-0) m.: 2 

 specimens, 25-27 mm. 



Depth of body 3!- to 4j in the length, length of head 3 to 3^ . Snout much shorter 

 than eye, diameter of which is 2f to 3 in length of head and much greater than the inter- 

 orbital width. Angle of praeoperculum nearly vertical. Maxillary expanded behind, 

 extending to a little beyond posterior margin of eye; lower jaw a little projecting. 

 Dorsal 11-13; origin sHghtly behind root of pelvic; longest rays about | head. Anal 

 22-24; origin just behind last dorsal ray. Pectoral 14-15 ; |- to f length of head. Pelvic 

 8. About 42 scales in the lateral Hne. A very small antorbital luminous organ above the 

 nostril and a somewhat larger one below the anterior part of the eye ; 2 on the prae- 

 operculum, the upper larger and level with the upper edge of the maxillary; 3 below 

 the lower jaw, the middle one the largest. PLO on lower part of pectoral base. 2 PVO, 

 close together and side by side. 5 PO, all level. VLO much nearer pelvic fin than 

 lateral line. 4 VO, the second scarcely elevated. 3 SAO, all close together and nearly 



