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PACIFIC SCIENCE, Vol. XIV, October I960 
B. Dorsal origin opposite anal origin and 
vent, all far forward, at level of or not far 
behind pectoral origin. No scales. Denti- 
tion powerful, large canines. No opercu- 
lar armature. Hind preopercle margin 
entirely below skin Pyramodontidae 
II. Parietals moderate, meet on midline. Max- 
illa not or barely expanded posteriorly. 
Pelvics absent. Scales absent. Vent and anal 
origin usually anterior to dorsal origin. 
Pectorals with less than 20 rays Carapidae 
Arnold’s (1956) revision of the Carapidae 
contains no mention of either Snyderidia or 
Pyramodon. 
In sum then, Snyderidia has been placed in 
the Lycodapidae, Carapidae, Brotulidae, and ten- 
tatively in the Pyramodontidae. As the first of 
these allocations is almost certainly erroneous, 
the problem that remains is to determine the 
relationship of Snyderidia to other ophidioid 
groups. 
Aside from Smith’s recent erection of the 
Pyramodontidae and the synonymizing of the 
Disparichthyidae with the Carapidae (see de 
Beaufort, 1951: 449; Arnold, 1956: 260, 261), 
the classification of the ophidioid fishes stems 
directly from Regan (1912). Three ophidioid 
families, distinguished by the characters listed 
in Table 1, were there recognized. So far as can 
be determined from Regan’s paper, the internal 
features recorded are based on skeletons of a 
single species from each family: "Brotula ja- 
yakari” of the Brotulidae, "Genypterus blacodes” 
of the Ophidiidae, and "Fierasfer acus” of the 
Carapidae. 
If these were small and uniform families one 
might allocate Snyderidia by simple reference to 
Table 1. However, the possibility of both in- 
ternal and external diversity exists in all three 
and has been abundantly verified in the Brotuli- 
dae (cf. Norman, 1939: 83, 84; Gosline, 1953: 
220-225). In view of this, it seems advisable to 
use a much broader base than Regan’s for the 
establishment of family definitions among the 
ophidioid fishes. Unfortunately such a base is 
only partly available. 
So far as the external features generally used 
are concerned, some members of the tremendous 
family Brotulidae nearly overlap the Ophidiidae, 
whereas others grade almost imperceptibly by 
way of Smith’s Pyramodontidae into the Cara- 
pidae. Whether external characters exist in these 
families that would provide better definitions 
remains unknown to this author, for only a few 
forms are available for examination. 
The present paper therefore will be con- 
cerned primarily with osteological features. Skel- 
etons that have been used here are those of 
Microbrotula, Dinematichthys, and Brotula pre- 
viously prepared (Gosline, 1953 ) , of Snyderidia, 
and of a specimen of (presumably) Otophidium 4 
(without data) received from the U. S. National 
Museum. The following literature on inter- 
nal features has also been referred to: Emery 
(1880), Regan (1912), and Arnold (1956). 
Cranium : Unlike the other crania at hand, that 
of Snyderidia is thin walled and rather fragile. 
The sutures in many instances — e.g., on the back 
of the skull, between the lower portion of the 
sphenotic and pterotic, and in the alisphenoid 
area — are difficult to make out, and in Fig. la 
and b some of these have been drawn with con- 
siderable misgiving. 
Regan (1912) made use of three cranial 
characters in separating the Brotulidae from the 
Carapidae (Table 1, nos. 6-8). Two of these 
concern the development of the supraoccipital. 
According to Regan (1912) the parietals are 
4 In view of the varied interpretations of ophidiid 
genera (cf. Harry, 1951; Norman, ms., 1957) it seems 
advisable to give a brief description of the specimen 
skeletonized. 
Total length 185 mm. Pelvics inserted about below 
the anterior border of the pupil, the outer filaments a 
little over twice as long as the inner. Gill membranes 
attached to the isthmus below rear border of eye. Four 
developed gill rakers. Pseudobranch consisting of 
about five short filaments. Head scaleless. No spine on 
snout tip. Opercle ending in a strong, concealed, little 
flattened spine. Anterior nostril on snout rim; poste- 
rior about midway between snout rim and anterior 
border of eye. Teeth many-rowed on jaws, vomer, and 
palatines, the rows tapering in width from front to 
rear. Outer jaw teeth rather long, curved, and sharply 
conical; inner similar but smaller, straighter, and 
blunter. Preorbital not differing greatly from sub- 
orbitals. 
Scales on body rectangular, not embedded and not 
overlapping, the long axes of adjacent scales fre- 
quently at right angles to one another. Dorsal and 
anal rays covered with flesh, dark edged posteriorly 
and around tail. Air bladder short, terminating rather 
abruptly posteriorly, with a hole in its posteroventral 
face. 
