BULLETIN OF THE UNITED STATES FISH COMMISSION. 
406 
distance between them 1.4 in eye. First dorsal spine strong, roughened laterally, inserted above 
gill-opening; other dorsal spines slender, nearly smooth, pointed, the third longest, its length about 
equaling that of snout; dorsal rays slender and weak; shorter than the spines, the longest about 2.8 
in head; anal spines slender and pointed, the second a little the longer, its length equaling diameter 
of eye; anal similar to soft dorsal but somewhat lower; caudal deeply lunate, the lobes not greatly 
produced, the upper slightly the longer; ventral spines long, rather strong, reaching base of second 
anal spine, their length equaling that of longest dorsal spine; pectoral of moderate length, 4 in head. 
Color in alcohol, nearly uniform olivaceous brown, paler below; dorsal fin darker brown, crossed by 
3 broad longitudinal lighter bands; on the spinous portion the lighter and darker markings are broken 
up into more or less vertical bars; membrane between first and second dorsal spines with a pale or 
transparent area on distal portion, the edge of fin narrowly black; anal similar to dorsal, but with 
less distinct bands; caudal uniform dusky; pectoral dusky, paler at tip; ventrals dusky. 
This species was not obtained by us. The only known examples are the type and one cotype 
secured by Jenkins at Honolulu in 1889, length 9 and 10 inches, and another example 11.2 inches 
long, recently obtained by Mr. Berndt at Honolulu. 
Callicanthus mctoposophran Jenkins, Bull. U. S. Fish Com., XXII, 1902, 481 (Sept. 23, 1903), fig. 31, Honolulu. (Type, No. 
50706, U. S. N. !VI.; eotype, No. 7727, L. S. Jr. Univ. Mus.) 
Fig. 178 . — Callicanthus metoposophron Jenkins; from the type. 
Group PLECTOGNATHI. — The Plectognathous Fishes. 
One of the most important offshoots of the . Icanlhopteri is the group or order Plectognatlii, includ- 
ing the 3 suborders of Sclerodermi, Odracodermi, and Gymnodontes. The extremes of this group show 
a remarkable divergence from the usual type of spiny-rayed fishes. The more generalized forms are, 
however, very close to the group called Squamipinnes, and especially to the family of Teutliididx. 
There can be no doubt of the common origin of Balididse and Acanthuridx and that the divergence is 
comparatively recent. The close connection of these groups leads us to - subordinate the 'Plectognathi 
to the Accmtliopteri and to place its 3 suborders in their natural position as an offshoot from the Squami- 
pinnes. The Plectognathi may be thus defined : a 
Scapula suspended to the cranium by a post-temporal which is short, undivided, and ankylosed 
to the epiotic. Premaxillaries usually coossified with the maxillaries behind and the dentary bones 
with the articular; interopercle a slender rod; lower pharyngeal bones distinct; upper pharyngeals 
laminar, usually vertical and transverse; skin usually with rough shields or scales or bony plates; 
a The definition of this group is modified chiefly from Doctor Gill. (Proc. U. S. Nat. Mus., 1884, 412.) 
