580 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 42. 



lying between tlie divergent premaxillaries ; maxillary very long and 

 slender, and joined to the side of the mandible; lower jaw included, 

 rounded; long, depressible, unequal curved or hooked teeth in each 

 jaw; a pair of long, hinged, hooked teeth on each side of upper jaw 

 near the tip of the premaxUlary, these lying against the roof of the 

 mouth and capable of lateral motion; eye small, near angle of mouth; 

 nostril close to eye; gill openings small, slit-like; gill arches 3, short; 

 lower part of body and head covered with spinif erous tubercles ; soft 

 dorsal well developed, with 8 rays; a single subdermal cephalic spine 

 (ilHcium) extending from frontals nearly to tip of snout, dUating into 

 a small, bulbous organ; the latter projects and is surmounted by a 

 tooth-bearing pedicel; caudal large; anal small; pectoral rays 15. 

 (TTiaumaticJithys; from daufia, a wonder, and ixd^C, a fish.) 



THAUMATICHTHYS PAGIDOSTOMUS Smith and Radclifle, new species. 

 Plate 72, figs. 1, 2. 



Dorsal 6; caudal 8; anal 4; pectoral 15. 



Head large, broad, rectangular, depressed, constricted immediately 

 behind posterior angle of jaws, its length (measured from anterior 

 margin of branchial aperture) 2.06 in total length of fish to base of 

 caudal (2.8 to tip of caudal), its breadth 1.43 in its length, its depth 

 2.5 in its length; body slender, compressed, tapering; caudal peduncle 

 slender, its depth 6.6 in head; eye minute, 20 in head, 11.3 in snout, 

 situated on upper edge of angle of jaws; snout (measured tp tip of 

 projecting premaxillaries) 1.81 in head; mouth horizontal, cavernous, 

 the slender and widely separated cranial bones, with the thin skin, 

 forming an exceedingly elastic boundary ; upper j aw much the longer, 

 the tip of the evenly rounded lower jaw not reaching to the cavity 

 between the premaxillaries; maxUlaiy veiy slender, not dilated at 

 tip, fitting into the side of the mandible near angle of jaw; premaxil- 

 laries 1.5 in head, the articular processes elongate, divergent; mandi- 

 ble 1.88 in head; teeth long, unequal, cardiform, depressible, with 

 incurved tips, those on upper jaw the larger, arranged in groups; a 

 wide toothless space at tip of upper jaw where the premaxillaries 

 diverge; a pair of long, liinged, hook-like teeth, the largest 2.35 in 

 premaxillary, inserted near inner process of premaxillary and lying 

 closely applied to roof of mouth, these teeth capable of being swung 

 forward laterally like cranes so as to close the toothless space in front 

 of j aw; a small patch of small teeth on either side of roof of mouth pos- 

 teriorly; gullet constricted, apparently distensible to a considerable 

 degree ; the single detached dorsal spine lying in skin on top of head 

 and extending nearly to margin of upper jaw, where it terminates in a 

 bulbous process about size of eye; this bulb projects through roof of 

 mouth into the oral cavity and appears to be a luminous organ, and 

 from it there extends downward into the mouth a slender pedicel 



