Opisthoteuthis calif orniana — Pereyra 
bottom and settles down again, are supporting 
evidence. 
Although the animal is primarily a bottom 
dweller, it is doubtful that it burrows in the 
mud. The locomotory behavior of specimens 
in an aquarium, the capture of one specimen 
just off the bottom, and the lack of mud and 
infauna in the gut imply epibenthic existence. 
Although most of the food organisms recovered 
from the gut were not epi- or infauna, indicat- 
ing a truly benthic feeding habit, none ap- 
peared morphologically to be pelagic. 
Hydrographic data have been taken coinci- 
dent with some of the captures of O. calif orni- 
ana. Bottom water temperature ranged from 
4.6 to 5.8° C, and salinity was approximately 
34.1 %c, and bottom type consisted primarily 
of greenish silt, occasionally mixed with small 
amounts of sand and clay. Since this bottom 
type is associated with a smooth bottom which 
is, therefore, more conducive to trawling, flap- 
jack devilfish may inhabit rocky areas which 
have not as yet been sampled. 
Authors in the past have classified Opistho- 
teuthis as an abyssal animal ( Dollo, 1912 and 
Meyer, 1906). According to Hedgpeth (1957: 
21) the limits of the abyssal region are from 
2000 or 3000 m (1092-1622 fathoms) down- 
ward to about 6000 m (3241 fathoms). The 
upper limit may better be defined as the region 
in which the temperature never exceeds 4° C. 
Bruun (1957:643) remarks that in the Atlan- 
tic Ocean this temperature is not reached until 
about 2000 m (1082 fathoms), whereas in the 
Indian and Pacific oceans it is as high as 1500 
or 1000 m (811 or 541 fathoms). If we note 
the upper limit of the abyssal region in the 
areas of capture, then we must conclude that 
Opisthoteuthis has not been taken in the abys- 
sal zone. With few exceptions, captures of 
Opisthoteuthis have been reported from the 
continental slope. These exceptions were a few 
specimens of O. depressa taken on the conti- 
nental shelf off Japan at the higher latitudinal 
limits of this species’ range (Sasaki, 1920: 
170) where bottom temperatures are lower 
(Dr. Felix Favorite, personal communication); 
and one specimen of O. calif orniana captured 
off Alaska. 
439 
Evolutionary Considerations 
From what is known of the morphology and 
habits of Opisthoteuthis, most authors have felt 
that members of this group are highly evolved, 
exhibiting numerous degenerate conditions 
(Berry, 1952; Dollo, 1912; Meyer, 1906; Rob- 
son, 1925 and 1929; and Verrill, 1896). The 
evolutionary significance of some of these con- 
ditions is not thoroughly understood and is 
questioned by Robson (1929). 
The following observations are further addi- 
tions to the concept of specialization and de- 
generation for Opisthoteuthis: (1) the pres- 
ence of large suckers which are ineffective for 
holding on, and (2) a pulsating swimming 
motion through use of the web, together with 
highly coordinated fin movement. 
The adaptive significance of the deepening 
of the web convergently in many of the Octo- 
podidae is suggested by the locomotory pattern 
exhibited by Opisthoteuthis and others ( Bathy - 
polypus arcticus, Eledone moschata, E. cirrosa, 
Cirroteuthis, and Cirrothauma ) . All have an 
extended web and use it in some phase of 
swimming. When the behavior patterns of 
more deep-webbed species are known, we prob- 
ably will find that the extension of the web is 
primarily a locomotory adaption. 
SUMMARY 
1. Thirty-nine records of the flapjack devil- 
fish, Opisthoteuthis calif orniana, from off the 
coasts of Oregon, Washington, and Alaska are 
reported. 
2. The known geographic range of this spe- 
cies is extended from northern California to 
the Aleutian Islands, Alaska, and the known 
bathymetric range is now defined from 68 to 
450 fathoms (124-823 m). 
3. Males occur in shallower water than fe- 
males, and there is an indication that the males 
move seasonally, being found in shallower 
water during the summer. The overall sex ratio 
appears to be close to 1:1. 
4. At the depths of greatest availability 
(375 and 450 fathoms [686 and 823 m]) off 
northern Oregon a catch rate of one specimen 
per one-hour drag was recorded. 
5. Observations on living animals revealed 
that the general appearance was more nearly a 
bell-shape than a plano-convex disc, with the 
