DEWITT: NEW GENUS AND SPECIES OF EELPOUT 





FIGURE 1.— Lateral view of holotype of Exeehodontes daidaleus n.gen. and n.sp., USNM 211797, 96.3 mm SL. 



thousandths of standard length unless otherwise 

 indicated. 



Head relatively short, 143 of SL, slightly com- 

 pressed, its depth and width at cheeks, 78 and 69 of 

 SL. Snout slightly greater than diameter of eye, 39 

 of SL, very bluntly rounded in both dorsal and 

 lateral views. Nostrils 21 from tip of snout and eye, 

 36 apart, all of SL, placed at lateral edges of 

 slightly bulbous median part of snout. Eyes placed 

 high on head, but not bulging into dorsal profile, 

 their diameter 34 of SL, placed 38 of SL apart 

 (bony interorbit about 18 of SL). Postorbital part of 

 head 76 of SL. Gill slit moderate, extending ven- 

 trally almost to lower edge of base of pectoral fin. 



Gape of mouth relatively short, maxilla extend- 

 ing posteriorly to below anterior edge of pupil, 

 length of upper jaw 57 of SL. Teeth all relatively 

 small; those of upper jaw in a single, irregularly 

 spaced row, a few teeth in anterior one third of jaw 

 somewhat enlarged, especially adjacent to sym- 

 physis. Teeth of lower jaw in two distinct rows; 

 inner row on dorsal edge of dentary, teeth some- 

 what irregularly spaced, none enlarged; outer row 

 on lateral and anterior edge of dentary such that 

 teeth are directed outward (most teeth in outer 

 row are missing; cavities in dentary indicate prob- 

 able tooth positions). Lower jaw included in upper, 

 leaving anterior teeth of upper jaw and outer row 

 of lower jaw visible when mouth is closed. Vomer 

 with two teeth (one missing, but a large tooth 

 cavity present); palatines edentulous. Gill rakers 

 of anterior series of first arch 0+0 + 12; those of 

 posterior series + + 11; all are short and blunt. 

 About nine small nubbins present in posterior 

 series of last arch. Pseudobranchiae absent. 



Grooves behind lips of both jaws interrupted at 

 symphyses; upper jaw appears to be nonprotrac- 

 tile. Lips narrow, not expanded. No fleshy pro- 

 tuberances or crests present on lower jaw; no 

 cephalic lateral-line pores present anywhere on 

 head (Figures 1, 2). Oral valves present in both 

 jaws, that of lower jaw appearing double, one thin 

 and membranous, lying somewhat anterior and 

 overlying a more fleshy one. Tongue fleshy. Bran- 

 chiostegal rays six on both sides. 



Body slender and compressed, its depth and 

 width 78 and 48 of SL; pectoral to pectoral distance 

 71 of SL. Lateral line not prominent; a single, 

 prominent, raised neuromast present on each side 

 just above and slightly anterior to upper end of gill 

 slit; a few similar organs (appearing as pale spots) 

 visible in a line curving downwards toward mid- 

 line behind pectoral fin. Skin delicate but firm on 

 the body. Scales absent. Vertebrae 19 + 78 = 97 

 (including urostylar vertebra). Vertebrae appear 

 in radiographs to be amphicoelous with anterior 

 and posterior cones of equal size (Figure 3). 



FIGURE 2.— Ventral view of head of holotype of Exechodontes 

 daidaleus n.gen. and n.sp., USNM 211797, 96.3 mm SL. Missing 

 teeth in outer row of lower jaw outlined in dots to show presumed 

 position and size. 



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