SOUTH AMERICAN NEMATOGNATHI. 91 



Oaleichthys furthii Jordan, Proc. U. S. Nat. Mus. 1885, 366 (name 



only). 

 Tachisurus furthii Eigenm. & Eigenm. Proc. Cal. Acad. 2d Ser. vol. 



i, 1888, 146 (Panama). 

 Habitat : Panama . 



Body compressed posteriorly; profile slightly convex. 

 Head broad, tapering forward, its greatest width 1-f-lJ 

 in its length; width, at the angle of the mouth, 2f-2-f 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 without 

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



