66 U.S. NATIONAL MUSEUM BULLETIN 291 



No difference in the leng:tlis of the arms occurs between the two 

 species (figs. 10-13). The predominant arm formula in each species is 

 4.3.2.1. In abyssicola of 37 mm ML the fourth arms average about 

 15.5% longer than the first arms; in hacidifera of the same size the 

 fourth arms are 16% longer than the first arms. 



Figure 10. — Balhytevlhis abyssicola, B. bacidifera: scatter diagram of mantle length vs. 



Arm I length. 



DL, 



^, 



o. .^l o o 



.'^ .o.%o. % 

 • , ^•^ o rf>o o 

 •f • o 



0«9 *0*»0 



%• oooo° 



OMol* 

 OF«mol« 

 ,g? ">, t B.bocidif.ro 



Figure 1L — Bathyteuthis abyssicola, B. bacidifera: scatter diagram of mantle length vs. 

 , Arm II length. 



