MUSEUM OF COMPARATIVE ZOOLOGY. 105 



Hyd. 2628. Surface to 200 fathoms. (Between Cape San Francisco and 

 Galapagos, about 250 miles from the Galapagos.) 

 3414. Surface to 300 fathoms. (Between Galapagos and Acapulco, 

 350 miles from land.) 



12° 34' N. 97° 21' W. (Between Galapagos and Acapulco, about 300 miles 

 S. E. of Acapulco). 



Geographical Distribution. Central Atlantic, Pacific; New Guinea and 

 Philippine Islands. Surface and 1,300-1,500 meters. 



Stylocheiron flexipes Ortmank. 



Plankton Exp. 1893, p. 18, PI. I. fig. 7. 



Stations of the "Albatross": — 



3382. 200 fathoms. t (Gulf of Panama, about 60 miles from the 



100 fm. line.) 

 Hyd. 2627. Surface to 1,770 fathoms (open part of net). (Between Cape 



San Francisco aftd Galapagos.) 



Geographical Distribution. Central Atlantic, between surface and 500 m. 



MYSIDACEA. 



BOREOMYSIS G. 0. Sars. 



Sijnopsis of the known Species. 



nj Eyes of the usual structure, with visual elements. 



I'l Eye-peduncles conical or fusiform, cornea moderately or not at all 

 expanded, not projecting laterally beyond the carapace. 

 Cj Frontal margin produced to a sharp rostrum or pointed in the middle, 

 dj No lateral frontal spines over the eyes. 



e^ Eye-peduncle conical, cornea somewhat expanded. Rostrum well 

 developed. 

 fj Eye-peduncle not prolonged as a tubercle over the cornea, 

 gi Rostrum lient upwards. 



1. B. arriicn (Kroyer). Greenland, Norway, 200-400 fathoms. 



(Cf. r;. 0. Sars, Monogr. Norg. Mys. 3, 1879, p. 10, 

 PI. XI.-XIII. 



gg Rostrum perfectly horizontal. 



2. B. nnhills G. O Sars. Spitzbergen Sea, 459 fathoms. (Den 



Norske Nordhavs Exp. Zool. Crust. 1885, p. 54, PI. V. 

 figs. 22-28.) 



fj Eye-peduncle prolonged to a sharp tubercle over the cornea. 



3. B. ni/if'iirnic'i n. sp. Gulf of California. 



