100 MEMOIRS OF THE CARNEGIE MUSEUM 



scales have been mistaken for photophores in some instances. Thus the lower 

 of the pectoral series, two in the thoracic series and one of the supraventrals 

 belong in this category and are redundant. If the number of gill-rakers is 

 correctly given as 9 + 13, this may serve to distinguish this species, as in 

 several specimens of L. elongatus from the Atlantic, there are constantly eighteen 

 to twenty rakers on the anterior portion of the outer arch. 



26. Lampanyctus nannochir (Gilbert). 

 Myciophuni nannochir Gilbert, Proc. U. S. Nat. Mus., XIII, p. 51; Pacific 



coast, U. S. 



A single specimen was secured at Albatross Station 5030, in the southern 

 part of the Okhotsk Sea, southeast of Cape Patience, Sagalin; hitherto unre- 

 corded in the western Pacific south of Bering Sea. The specimen has all the 

 characters which serve to distinguish this form from L. leucopsarum; the larger 

 photophores, the smaller number of luminous scales on caudal peduncle, the 

 somewhat lower position of the upper series of photophores on the sides, and 

 the presence of three instead of four precaudals. Occasionally a specimen of L. 

 nannochir has a fourth precaudal on one side, but no case has come under our 

 notice in which L. leucopsarum has but three precaudals. In addition to these 

 characters, it was ascertained during the cruise of 1906 that in life the photo- 

 phores of nannochir are constantly a bright ruby-red, whereas in leucopsarum 

 they are golden-yellow. No trace of this difference persists in preserved mate- 

 rial. The two species are extremely closely related; occasionally a young speci- 

 men is difficult to determine. Furthermore, they accompany each other 

 throughout their range. But a number of minor characters have thus far 

 shown a constant correlation which makes it impossible to ignore them. 



27. Lampanyctus niger (Giinther). 

 Nannobrachium nigrum Giinther, Deep Sea Fishes Challenger, 1887, p. 199, 



PL LII, fig. B. 



A single specimen 71 mm. long, from Albatross Station 4958, in the Bungo 

 Channel, depth 405 fathoms. The present status of the species is very unsatis- 

 factory, as the original description and figure have no reliable indication of the 

 distribution of the photophores. Our specimen is much slenderer than is 

 indicated in the figure by Brauer (Die Tiefseefische, 1906, p. 242, fig. 159), 

 agreeing in this respect and in general appearance with Glinther's figure above 

 cited. The position of the photophores agrees in most details with that shown 

 by Brauer. 



