232 EXPEDITION OF THE "ALBATROSS," 1899-1900. 



opposite first caudal ray ; the fourth on the lateral line, well behind and 

 above the third, and separated from it by a wide interval. Luminous patch 

 on imderside of caudal peduncle involving rudimentary caudal rays and 

 extending forwards to below first postero-anal photophore ; that on back 

 of caudal peduncle short, extending but little in advance of the rudimentary 

 caudal rays, which it covers. Integument of body rubbed so that complete 

 distribution of luminous patches cannot be given, but a series is evident 

 along base of .anal fin, and another of four or five luminous scales on median 

 line between ventral and anal fins. 



General color blackish, the mouth and gill cavities, including gills and 

 gill-arches and gill-rakers, jet black. 



The Ceratoscopelus section of Lampanyctus, to which this species belongs, 

 contains also L. maderensis and L. ivanningi, and is characterized as follows : 

 (1) thoracic and ventral photophores each five in number, none of them 

 elevated ; (2) middle pectoral photophore in front of base of pectoral fin ; 

 (3) antero-anals forming an ^Xy-shaped curve, the first are nearest the 

 anal base, the last one or two elevated, forming a curve which includes the 

 single postero-lateral ; (4) precaudals 4 in number, sharply distinguished 

 from pcstero-anals ; (5) dorsal and anal short, about equal in length; 

 (G) luminous patches following a definite arrangement which is similar in 

 all the species. 



Most nearly related to L. icaniniir/i Liitken from the Atlantic, the latter 

 having a])parently a much blunter, more rounded snout, but the description 

 inadequate for detailed comparison. 



Lampanyctus omostigma, sp. nov. 



Plate 5. 



Type 62 mm. long, from the surface at 10° 57' 35" N. Lat., 137° 35' 25" 

 W. Long., in the open Pacific about 1000 miles north of the Marquesas 

 Island.s. 



Very closely allied to L.macropierm Brauer (Zoul. Anz., 1904. 28, pp. 397, 

 404, fig. 5, p. 381), from the Indian Ocean, apparently differing in the 

 following respects: 



