1911.] NATURAL SCIENCES OF PHILADELPHIA. 561 



first premaxillary fang, and others all graduated down till minute. 

 No other teeth on roof of mouth. Tongue small, bony, not free, 

 with median osseous keel. Nostril simple pore close before front 

 orbital edge. Mandible large, greatly compressed, rami not elevated 

 in mouth, conic process at symphysis, and slight flange along lower 

 external edge of each branch. Interorbital depressed, and like rest 

 of cranium bones thin. As viewed from above, brain easily dis- 

 tinguished through thin cranial walls. Along each side of head 

 above an osseous keel. Opercle narrow, deep. Subopercle smaller 

 than eye. Hind preopercle edge slightly convex, inclined down 

 behind. 



Gill-opening forward about opposite first third in snout. Rakers 

 about 4+15 minute firm pointed denticles along inner edge of 

 gill-arch. Filaments If in eye. No pseudobranchiae. Branchios- 

 tegals about twenty each side, mostly uniform, short, slender, only 

 little shorter each end. Isthmus long, slender, compressed narrowly 

 and scarcely tapering back behind. 



Scales small, thin, smooth, mostly all fallen, and now distinguished 

 only from pockets as apparently of mostly uniform size and disposed 

 in several even longitudinal series. Head and fins entirely naked. 

 A single crescentic series of small infraorbital photophores, first 

 largest and begins in small dark pigment blotch opposite front edge 

 of eye, and entire series close to eye. Below this directly opposite 

 eye centre close to maxillary edge a rather large and conspicuous 

 photophore. Along outer surface of maxillary meclkmly and con- 

 tinued well down its course a single series of small photophores, 

 anteriorly quite small and enlarged a little posteriorly. In lower 

 corner of cheek a series of 5 photophores, and opposite just behind 

 preopercle edge another photophore. Behind upper edge of pre- 

 opercle articulation a large photophore, and still another at lower 

 edge of subopercle. A rather large photophore between base of 

 each branchiostegal ray on branchiostegal membrane. On inner 

 surface of preopercle, within gill-opening, a series of small photo- 

 phores close together. Photophores from isthmus to pectoral 11, 

 from pectoral to ventral 19, from ventral to anal 25, from anal to 

 caudal 10. Abdominal photophores as double median row, and 

 another row each side, preventral 19, postventral 26, though median 

 double row with series very close. Upper row well separated and 

 along parallel in space below, or between it and low T er series, a parallel 

 series of numerous minute or close-set photophores. This series 

 disappears at anal, likewise median double series. Along anal base 



