Lava-Flow Fishes — G osline 
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TABLE 1 
Differences Between Ophidioid Families Noted by Regan ( 1912 : 277 - 280 ) 
BROTULIDAE 
OPHIDIIDAE 
1. Pelvic fins, when present, jugular 
2. Vent remote from head 
3. Gill openings wide, with gill 
membranes separate and free 
from isthmus (except in Derma- 
topsis ) 
4. Mouth protractile 
5 . Pterygoid and mesopterygoid sep- 
arate 
6. Parietals separated by supraocci- 
pital 
7. Supraoccipital forms, with exoc- 
cipitals, a strong median crest 
which does not project above 
upper surface of skull 
8. Opisthotic is not enlarged, 
though basioccipital and prootic 
form a rather prominent auditory 
bulla 
9. Lower fork of posttemporal is 
directly attached to opisthotic 
10. Coracoid and scapula are sepa- 
rated by cartilage 
11. Cleithra normal 
12. Vertebrae (in Brotula multibar- 
bata) 15 + 40 
13. First 5 vertebrae with sessile ribs, 
3rd and 4th pairs being ex- 
panded 
14. Strong transverse processes on 
vertebrae 6-15 
Pelvic fins inserted between rami of 
lower jaw 
Gill membranes attached to isthmus 
behind pelvics 
Pterygoid and mesopterygoid anky- 
losed 
Lower fork of posttemporal is 
shortened and attached to opis- 
thotic by ligament 
Coracoid and scapula are in contact 
Cleithra prolonged within isthmus 
as a pair of slender processes, 
with pelvic bones attached to 
their extremities 
Vertebrae (in Genypterus blacodes ) 
20 + 52 
First 5 vertebrae with sessile ribs, 
but only 3rd expanded 
Parapophyses on vertebrae 6-11 are 
strong and broad, much as in 
Merluccius; rest are normal 
CARAPIDAE 
Pelvics absent 
Vent placed at throat 
Mouth nonprotractile 
Parietals meet above supraoccipital 
Occipital crest is weak, and exocci- 
pitals do not take part in its for- 
mation 
Enlarged opisthotic reaches basioc- 
cipital, sharing with that bone 
and prootic in formation of audi- 
tory bulla 
Lower fork of posttemporal is re- 
duced to a little knob 
Coracoid and scapula are in contact 
Vertebrae (in Carapus acus, fide 
Emery) 125-144, of which 17 or 
18 are precaudal; 26 precaudal 
vertebrae in Carapus dentatus 
separated by the supraoccipital in the brotulids 
but meet above in the carapids. I have already 
shown (1953: 232) that Dinematichthys, among 
three brotulids examined, had the parietals meet- 
ing above. In Otophidium as well as in "Ophi- 
dium Rochet ” (Emery, 1880, pi. 3, fig. 26) the 
parietals are separated by the supraoccipital. In 
Pyramodon (acc. Regan, 1914) they are sepa- 
rated, but in Snyderidia and the two carapids 
figured by Emery ( 1880, pi. 3, figs. 18, 23 ) they 
meet. Whether the parietals are separated or 
meet is correlated with the size of the occipital 
crest (Table 1, no. 7); among the skeletons 
available it would seem that the supraoccipital 
is best developed in the narrow, highheaded 
forms, e.g., Otophidium (Fig. 1 c), and least de- 
veloped in the broad, flatheaded species, e.g., 
Dinematichthys. That the size and extent of the 
supraoccipital have any great systematic value 
in this suborder seems questionable. 
The relative size of the opisthotic (Table 1, 
no. 8) is another feature variable within the 
