164 DEEP SEA FISHES. 



terorbital space, one ninth as long as the head, or one half of the distance 

 from the mouth. Nostrils small, anterior near the end of the snout, with a 

 groove containing sensory papillai from the hinder part of its valve down 

 and forward to the intermaxillary ; posterior distant from the eye less than 

 one diameter from the front of the orbit. Opercular spine large, strong ; 

 no other spines on the head. The lower angle of the operculum is spine- 

 like, but is not free and is hidden by the skin. Gill membranes united for 

 a short distance, free fi'om the isthmus. Gills four, a slit behind the fourth. 

 Gill rakers slender, elongate, longest as long as the eye, eight developed on 

 the first arch which also bears five or six rudiments at each end of the series. 

 Pseudobranchite very small. Air bladder large. Dorsal origin little back- 

 ward of the axil of the pectoral, height in midlength equal to the length of 

 the snout. Snout to anal fin two and one third times the length of the 

 head. Vertical fins united, bases thick and covered by scales. Caudal nar- 

 row, pointed, nearly half as long as the head. Pectorals as long as the 

 head, very flexible, with five or six of the lower rays free for about half of 

 their length, resembling in a measure Dicrolene or Pteroidonus, but the free 

 extremities are not produced backward of the other rays of the fin. Ven- 

 trals small, longer than the snout, less than one diameter of the eye apart, 

 below the humeral symphysis ; each fin composed of two rays, separated to 

 their bases, and varying from somewhat inflated and blunt to acuminate or 

 filamentary at the ends. Scales small, thin, flexible, concentrically striate; 

 also with radiating strias, many of which do not reach the centre of the 

 scale, and with the spaces between the striae reticulated. Lateral line ap- 

 parently irregular, traced as far as to the origin of the anal. 



Fins, lower parts of head, gill membranes, and linings of mouth and body 

 cavity black ; muscular portions lighter, possibly tinted with purple in life ; 

 top and sides of head whitish. 



ERETMicnxHYS gcn. n. 



In general appearance resembling Bas.sozetus. Body compressed, taper- 

 ing from the head, elongate and slender in the caudal region. Head higher 



