28 BULLETIN 150, UNITED STATES NATIONAL MUSEUM 



Bathymetrical distribution. — The Liparidae are found at all depths 

 from the tide pools down to 1,973 fathoms. The species are quite 

 common in the tide pools and down to 800 fathoms. Only 15 of the 

 114 species are recorded from below 800 fathoms, and 10 below 1,000 

 fathoms. Perhaps the number of species taken below 1 ,000 fathoms 

 bears the same relation to the number taken above this level as the 

 number of dredge hauls below 1,000 fathoms bears to the number 

 above. Doubtless the proportionate number of deep-sea forms will 

 be greatly increased. 



The three large genersi—Liparis , Careproctus, and Paraliparis — 

 while overlapping in their vertical distribution, are confined mainly 

 to different depths. The genus Liparis is represented down to 250 

 fathoms, but it is typically a tide-pool genus. Careproctus is typically 

 a genus of the dimly lighted regions. It is represented at all depths 

 from 30 or less to 1,823 fathoms, but half the species are found above 

 and half below the 300-fathom level. For convenience we have 

 designated this level as the center of population for the genus. Para- 

 liparis is typically a deep-water genus. It is represented at all 

 depths from 30 to 1,793 fathoms, but the center of population is at 

 about 500 fathoms, or 200 fathoms below that for Careproctus. 

 Poly per a is closely related to Liparis and is confined to the same region. 

 Temnocora, CrystallicTitJiys, Crystallias, and GyrinichtJiys are confined 

 to the same general region as Careproctus. Elassodiscus is confined 

 to greater depths. Acantholiparis and RJiinoliparis inhabit the same 

 depths as Paraliparis. 



The bathymetrical distribution of the species varies widely. The 

 tide-pool species have a vertical distribution of a few feet or fathoms, 

 while the bathybial species range through several hundred fathoms. 

 The maximum vertical distribution for species of several of the 

 genera is as follows : 



Range 

 fathoms Depth 



Liiparis dennyi 123 0- 123 



Liparis fucensis 213 0- 213 



Careproctus cypselur us 377 510- 887 



Careproctus mollis 347 135- 482 



Careproctus gilberti 380 102- 482 



Careproctus colletti 341 284- 625 



Careproctus melanurus 592 284- 876 



Acantholiparis opercularis 1, 291 682-1, 973 



Paraliparis ulochir 599 406-1, 005 



Paraliparis holomelas 1, 219 406-1, 625 



Rhinoliparis barbulifer 359 192- 551 



The vertical distribution of these species is of interest in connection 

 with the region between 250 and 500 fathoms. Somewhere within 

 this region is supposed to be the indefinite borderland between two 

 differently colored faunas. The red light rays fail to penetrate 

 below 273 fathoms. Whether this level or some other is the most 



