22 



PEOCEEDINGS OF THE N-A.TIONAL MUSEUM 



Ttemarks. — This species is the rarest of the members of the genus 

 captured by the Bache. The numbers are too few to enable any 

 generalizations to be made, but it is significant that no specimens 

 were taken at the surface. The species appears to be most fre- 

 quently caught between 75 and 150 meters and none were caught at 

 a greater depth than 700 meters. 



Genus THYSANOESSA Brandt 



26. THYSANOESSA GREGARIA G. O. Sars 



Occurrence 



Remarks. — This species appears to be widely and generally dis- 

 tributed throughout the tropical oceanic area, but is a deeper water 

 form than any of the species of EupJiausia, and, accordingly, was 

 captured in fewer hauls. It occurred in only 6 out of 46 hauls made 

 at depths of less than 200 meters, but in 9 out of 23 hauls at depths 

 from 200 to 1,800 meters. It is interesting to note that it was caught 

 at the surface on two occasions. 



Genus NEMATOSCELIS G. O. Sars 



27. NEMATOSCEUS MEGALOPS G. O. Sars 



Occurrence. — Station 10158, 600-0 m., 500 specimens; station 

 10160, 100-0 m., 4 specimens. 



RemarJcs. — This species again is a northern or boreal species and 

 was not taken in the tropical oceanic area. It occurred with Meganyc- 

 tiplianes norvegica and EupJiausia Icrohnii and this distribution in the 

 waters of the western Atlantic agrees well with previous observation 

 (Bigelow, 1914 (2) and 1917). Its relative abundance to E. Tcrohnii 

 at the two depths at which these species occurred is indicative of its 

 greater abundance in deeper water. At 100 meters only four speci- 

 mens were found among several hundreds of E. Tcrohnii, while at 600 

 meters 500 specimens were caught with about 2,000 of E. Jcrohnii. 

 This bears out the relative vertical distribution of the two species 

 noted by Bigelow (1917) from station 10233 over the continental 

 slope off Nova Scotia. 



