DIBRANCHICHTHYS NUDIVOMER. 99 
The differences between young and old in this species indicate that the 
species has been derived from one with a pointed snout and larger tubercles. 
The appearance is that of a more degenerate form than any of those in the 
collection from much greater depths. 
Station. Latitude. Longitude, Depth. Temperature. Bottom. 
3417 16°32! N: 99° 48’ W. 493 fathoms 40.6° F, Gn. M. 
3418 16° 33’ N. 99° 52’ 30” W. 660 “ 39° F. Br. 8. bk. Sp. 
3425 21° 19’ N. 106° 24’ W. 680) 6 39° F, Gn. M. and S. 
Originally described from 
Station. Latitude. Longitude. Depth. Temperature. Bottom. 
2992; 18S 30% IN. 114° 43/15” W.; 460 fathoms ; 41,.8° F.; Bk. S. R. 
DIBRANCHICHTHYS gen, n. 
Head and body depressed, together forming a broad rounded disk; cau- 
dal region distinct, slender, tapering. Rostrum excavated below in a recess 
lodging a trilobed protractile illictum. Nostrils and mouth anterior; latter 
transverse, oblique. Teeth absent from the vomer, present in villiform 
groups or bands on palatines, jaws, and tongue. Eyes large, with horizontal 
outlook. Gills two, none on first and fourth arches; gill openings small, 
placed superiorly in the axille; no pseudobranchix. Fins small, of few 
rays; anal narrow, backward of the dorsal. Skin above and beneath covered 
with unequal broad based spines or tubercles. 
In a general way this type is similar to Halieuteea and especially so to 
Dibranchus or Malthopsis. The discovery of this form is suggestive of a 
possible degradation of a number of closely allied genera to the rank of sub- 
genera in a revision of the family. 
Dibranchichthys nudivomer »p. n. 
Be: pO DD, Gc As 4s Viios RB. 132 C:; 9. 
In the regularity of its outlines this species approaches Malthopsis erina- 
cea; it is easily distinguished by being more oblong, having a shorter ros- 
trum, and by the weakness of the subopercular tubercle besides the more 
important feature, the absence of vomerine teeth. Body and head greatly 
depressed, together forming a disk in which the length or the width of the 
head is about seven eighths of the length of the body ; tail elongate, narrow, 
round, tapering from the vent. Crown slightly arched. Snout short, 
blunt, concave on the top, with a low ridge forward from the orbit and a 
