108 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.48. 



organs and found that they agree with one another and with my 

 figure quoted. The differences pointed out between the copulatory 

 organs of N. megalops from the North Atlantic and N. diffidlis from 

 the northeast Pacific are very easily seen and certainly so sharp, so 

 important, and so constant that they are sufficient for separating 

 N. diffidlis from N. megalops. I have hitherto been unable to find 

 any other character by which to distinguish the two species, and 

 consequently I am unable to separate their females, but it may be 

 possible that more detailed investigation of rich and well-preserved 

 material will show small differences between the females. 



The male from survey 541 has no rostrum and is 16.5 mm. long; 

 the male from survey 540 has a long female rostrum and is 18 mm. 

 The male from station 4407 has no rostrum and is about 19 mm.; 

 the male from station 4757 has the rostrum rudimentary and is 19 

 mm. long. The largest female, from off Guaymas, is 22 mm. long. 



Distribution. — Hitherto known only from the six stations recorded, 

 all situated in the northeast Pacific, between lat. 39 J ° N. and 26° N. 



37. NEMATOSCELIS ATLANTICA H. J. Hansen (1910). 



1910. Nematoscelis atlantica H. J. Hansen, Siboga Exp., vol. 37, p. 107. 



Occurrence. — Material from only two places in the northwest 

 Atlantic is at hand : 



Sta. 2210. August 21, 1884. Lat. 39° 37' 45" N.; long. 71° 18' 

 45" W. 2 specimens. 



Sta. 2565. August 28, 1885. Lat. 38° 19' 20" N.; long. 60° 02' 

 30" W. 3 specimens. 



Remarks. — This species, established on material taken by the Prince 

 of Monaco, will be described and figured in the report on that fine 

 collection. 



Distribution. — Previously known only from the warmer temperate 

 area of the eastern North Atlantic. 



38. NEMATOSCELIS MICROPS G. O. Sara (1883). 



1910. Nematoscelis microps H. J. Hansen, Siboga Exp., vol. 37, p. 107, pi. 15, 



figs. 2a-2k. 

 1912. Nematoscelis microps H. J. Hansen, Mem. Mus. Comp. Zool., vol. 35, No. 4, 



p. 259, pi. 9, figs. Aa-Ad; pi. 10, figs, la-16. 



Occurrence. — It has been taken at five places in the northwest 

 Atlantic : 



Sta. 2045. July 31, 1883. Lat. 40° 04' 20" N.; long. 68° 43' 50" 

 W. 1 specimen ( adult male) . 



Sta. 2195. August 5, 1884. Lat. 39° 44' N.; long. 70° 03' W. 

 1 specimen ( adult male) . 



Sta. 2230. September 12, 1884. Lat. 38° 27' N.; long. 73° 02' 

 W. 1 specimen. 



Sta. 2172. July 20, 1884. Lat. 38° 01' 15" N.; long. 73° 44' W. 

 1 specimen. 



