264 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM, 
hyomandibular and quadrate bones ;* without maxillary bones or dis- 
tinct posterior bony elements to the mandible; with an imperfect scap- 
ular arch remote from the skull; and with separately ossified but im- 
perfect vertebra. t 
FAMILY EURYPHARYNGID. 
Nouvelle famille Vaillant, Comptes Rendus. Acad. Sc. Paris, t. —, p. 1226, Dee. 11, 
1882 (not named), 
EBurypharyngide Gill, Science, v. 1, p. 231, March 30, 1883. 
Lyomeres with the head flat above and witha transverse rostral margin, 
at the outer angles of which the eyes are exposed, with the jaws exces- 
sively elongated backwards and the upper parallel and closing against 
each other as far as the articulation of the two suspensorial bones, with 
minute teeth on both jaws, with a short abdomen and long attenuated 
tail, branchial apertures nasrow and very far behind, dorsal and anal 
fins continued nearly to the end of the tail, and minute pectoral fins. 
The mandibular rami are exceedingly narrow and slender, but the 
jaws are extremely expansible and the skin is correspondingly dilatable ; 
consequently an enormous pouch may be developed. Inasmuch as the 
slenderness and fragility of the jaws and the absence of raptorial teeth 
(at least in Gastrostomus) preclude the idea of the species being true 
fish of prey, it is probable that they may derive their food from the 
water which is received into the pouch, by a process of selection of the 
small or minute organisms therein contained. 
The peculiar closure of the anterior half of the upper jaws upon each 
other, and the co-ordinate joint between the hyomandibular and quad- 
rate elements of the suspensorium are doubtless correlated with the 
mode of ingestion or selection of food. The skin constituting the pouch, 
it may be added, has a peculiar velvety appearance, and also reminds 
one of the patagium or wing membrane of a bat. But a more detailed 
summary of the salient characteristics of the type may be justly de- 
manded at once. 
OSTEOLOGY. 
The skeleton is noteworthy for its simplicity or rather fewness of its 
parts, but the homologies of these parts are, for that very reason, not 
evident at first sight. We necessarily confine our attention to Gastros- 
tomus, as the parts of Burypharynx have not yet been described or 
figured. 
The cranium above is really pentagonal, but apparently, in the main, 
transversely quadrate, expanding backwards around the foramen mag- 
num (which is conspicuous from above) and forwards into the ethmoid 
enya, which is a sais from the main spention by a sirneae 
“We find neither lveidean eparatas nor opere ‘all ar pieces. VAILLANT. 
+ “It is important to indicate the complete absence of the swimming bladder.”— 
VAILLANT, 
