PSEUDONUS ACUTUS. 169 



Plate XXXIX., figs. 3-6. The anal aperture is immediately in front of the 

 cage. The papilla when at rest is directed upward against the body. When 

 the cage is bent downward the papilla is directed horizontally backward, or 

 possibly downward when in function. Dorsal origin near midway from base 

 of pectoral to vent; anal origin below the twenty-fifth ray of. the dorsal. 

 Pectorals short, two fifths as long as the head, bases deep. Ventrals close 

 together, little backward of the humei'al symphysis, of a single filamentary 

 ray, as long as the pectoral. Vertical fins confluent ; caudal narrow, median 

 rays longer, one third as long as the head or longer. Pyloric appendages 

 two, comparatively short and thick Mucous cavities and pores large. 

 Scales absent from head on the top, snout and below, present on the sides. 

 Lateral line distinct, parallel with the dorsal to a point below the fifteenth 

 ray or thereabout, thence descending to the middle of the flank to continue 

 to the tail. The viscera are figured on Plate XXXIX. (fig. 3). 



Browni,sh, uniform or tinted with olivaceous or reddish. 



Nineteen inches in total length. 



PsEUDONUS gen. n. 



Shape in a measure resembling that of Porogadus; body compressed and 

 tapering ; body cavity about half of the total length. Head medium, like 

 that of Mixonus in some respects, but more elongate. Mouth wide, upper 

 jaw projecting very little. Teeth in villiform bands on jaws, vomer and 

 palatines. Eight branchiostegal rays. Gill openings wide ; membranes 

 hardly united, free from the isthmus. No pseudobranchia^. No barbels. 

 No ventrals. Vertical fins united. An opercular spine. Channels of the 

 lateral canal system greatly developed on the head. 



Pseudonus acutus sp. n. 

 Plate XXXIX. fig. 1. 



Br. r. 8; D. 109; A. 81 ; V. ; P. 21; C. 10; LI. 77 ; Ltr. 27; D. to 

 A. 19. 



Moderately compressed ; depth near one seventh of the total length, 

 body chamber not far from one half. Head elongate, about as wide as deep, 



