SOUTH AMERICAN NEMATOGNATHI. 91 



Gakich(hi/s fiirthu Jordan, Proc. U. S. Nat. Mus. 1885, 366 (name 



only). 

 Tachisurus furthil Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. yoL 



i, 1888, 146 (Panama). 

 Habitat: Panama. 



Body compressed posteriorly; profile slightly convex. 

 Head broad, tapering forward, its greatest width 1|-1^ 

 in its length; width, at the angle of the mouth, 2|-2| in 

 the head. Top of head densely covered with fine gran- 

 ules. Occipital process about as long as broad, with a 

 median ridge, emarginate on its sides and at tip; inter- 

 orbital region with four smooth ridges, the inner 

 bordering the fontanel, the outer extending obliquely 

 backward from near the posterior nasal opening; sides 

 of head and snout with vermiculating mucous pores.- 

 Middle of the fontanel over the pupil. 



Eye strictly lateral, not entirely above the angle of the 

 mouth, its center in front of the posterior end of the 

 mandible, 2 in snout, 6-7 in head, 3|-4 in the distance 

 between the eyes. 



Maxillary barbels thin, reaching to the middle of the 

 pectoral or shorter, postmentals beyond base of pectorals,, 

 or sometimes not beyond edge of gill membrane; mentals 

 to edge of gill-membrane or shorter. 



Jaws about equal, the upper rather thin; teeth on the 

 intermaxillaries villiform; the mandible with villiform 

 teeth except the inner two or three series which are 

 granular; like the palatine patches irregular, suboval, 

 sometimes the anterior end, sometimes the posterior and 

 sometimes both ends pointed. 



Gill-membranes united, joined to the isthmus vnthout 

 a free margin. Gill-rakers long and slender, 4-|-ll. 



Axillary pore small; vertical series of pores present. 



Distance of dorsal from snout 2|-2| in the length; the 

 dorsal spine 1|-|1 in the head, on sides and front gran- 

 ular, with small, sharp teeth on its inner margin; the 



