54 BULLETIN 201, UNITED STATES NATIONAL MUSEUM 



The telson (fig. 10, /) is about three times as long as broad at its 

 base and the cleft is about one-sixth of the total length. The proximal 

 third of each lateral margin is unarmed. The distal two-thirds of the 

 lateral margins are armed with from 30 to 32 spines, which show a 

 suggestion of an arrangement into short series of one, two, or three 

 smaller spines between larger spines. The larger spines are, however, 

 not very much larger than the smaller spines and the arrangement into 

 series is not nearly so well marked as in B. rostrata, where the large 

 spines are considerably larger than the small spines between them and 

 the arrangement into series much more pronounced. Each apical lobe 

 of the telson has three moderately large spines on its border. The 

 cleft is armed with teeth and there is no "dilation" such as is seen in 

 B. rostrata. 



The outer uropod (fig. 10, e) has the proximal sixth of the outer 

 margin unarmed and terminating in a single spine. 



Length of adult specimens 19 mm. 



Occurrence. — California: Albatross stations 4406, 3 males and 3 

 females; 4407, 1 male; 4415, 1 male; 4427, 1 female; 4429, 1 male; 

 4461, 1 male ; 4493, 1 male ; 4513, 1 male and 1 female ; 4529, 1 immature 

 male; 4536, 1 male; 4541, 1 male and 2 females; 4544, 1 specimen. 

 British Columbia: Albatross station 4759, 1 female. Bering Sea: 

 Albatross stations 3307, 2 females: 4763, 3 males and 6 females; 4765, 

 8 females and 5 males ; 4766, 7 females and 4 males ; 4775, 2 females ; 

 4785, 1 female; 4793, 5 females and 1 male. Sea of Okhotsk: Alba- 

 tross station 4800, 11 males and 9 females, none fully mature. South 

 of Guaymas, Gulf of California, types*, identified by A. E. Ortmann 

 (1894). Off Peru: Albatross stations 4652*, 4675*, identified as B. 

 media by Hansen. 



Distribution. — Ortmann's specimens were collected off the coast 

 of California and Hansen's a little farther to the south off the coasts 

 of South America. The extensive list of records given here shows 

 that the species is widely distributed in the Pacific from latitude 13° 

 S. to latitude 55° N. and from longitude 79° W. to longitude 153° E., 

 off Peru to British Columbia and the Bering Sea. It is a bathypelagic 

 species and most of the specimens here recorded were caught in tow- 

 nets working at 200 to 400 fathoms. Illig has recorded B. media from 

 the Indian Ocean and from the Atlantic. 



Remarks. — From an examination of these specimens I have come 

 to the conclusion that there is no really valid character by which 

 to separate B. calif ornica Ortmann and B. media Hansen. A com- 

 parison of the figures given herewith with those illustrating B. media 

 shows the closest agreement between them and leaves no doubt that 

 the identity of my specimens with B. media is complete. Hansen 

 (1910, p. 24) had already dismissed B. calif ornica Ortmann as be- 

 ing too inadequately described to be recognizable, so that when, in 



