Jordan and Evermann. Fishes of North America. 2085 



775. ODONTOPYXIS, Lockingtou. 

 Odontopyxis, LOCKINQTON, Proc. U. S. Nat. Mus., n, 1879, 328 (trispinosus). 



Body very slender, depressed, tapering uniformly from head to caudal ; 

 head 3 to 4, the width of body 6 to 7, depth 6 to 8 in length of body. A 

 deep pit behind occiput with a longitudinal ridge in its bottom; plates in 

 dorsal series 35 to 40; both dorsal fins present; 4 (3) rays in first, 6 (7) in 

 second; teeth numerous on ja\vs, vomer, and palatines. Gill membranes 

 broadly joined to isthmus, without free fold; a single upright spine, on 

 median rostral plate; supraocular spines small, sharp; 2 pairs of blunt 

 occipital spines or tubercles. (6dov$, tooth; rtv&S, box.) 



2427. ODOMOPYXIS TRISPIXOSUS,* Lockingtou. 



B. (>; 1 D. 4 (occasionally 3) ; 2 D. 6 (occasionally 7); A. 5 to 7; P. 14; 

 V. 3 (1,2); C. 1-11-1 (sometimes 1-10-1); pyloric caeca 5 to 7 (1 or 2 very 

 small; 3 individuals). Body octagonal, the faces a little concave; spines 

 small, sharp, present 011 the dorsolateral and superior lateral series nearly 

 from head to caudal ; a few very weak ones on inferior lateral ; none on ven- 

 trolateral series; about 3 long, sharp spines on each side of base of caudal 

 on the terminal plates. Two or 3 pairs of plates between last ray of second 

 dorsal and first median plate, and 1 or 2 pairs between last anal ray and 

 first median plate ; 18 to 20 quite large, radially striated plates on breast, 

 6 or 7 of varying size in front of, and several minute spinous ones oh base 

 of pectorals; 3 or 4 strong plates on median part of gill membranes pos- 

 teriorly, 1 to 3 on each side in front, 3 or 4 on under side of jaw, so that 

 the whole of under side of head is well armored; 1 or 2 plates between 

 ventrals and vent, the latter surrounded by small tubercles. Head some- 

 what depressed, its depth -fa of its width, the latter 7 in length of body; 

 orbits nearly circular, the longitudinal diameter about 3 in head; a few 

 minute spines on eyeball above pupil; snout pointed, equal to orbit; 

 interorbital space concave, narrow, of longitudinal diameter of eye; 

 occipital and temporal ridges weak. A deep transverse pit behind occi- 

 put, broader in front, its bottom divided longitudinally by the cranial 

 ridge above the foramen magnum; suborbital ridge moderate, 1 spine on 

 preorbital, and a very blunt flat one at posterior edge of opercle; 1 or 2 

 blunt flat projections below the latter spine; opercle with a ridge and 3 

 to 7 or 8 minute spines or prickles along its posterior border. Cheek below 

 suborbital ridge entering into ventral surface of head, with 2 or 3 well- 

 developed plates; several small plates in a longitudinal series behind 

 orbit, above suborbital and preopercle, the highly movable median 

 rostral plate with a single upright spine, its lateral expansions free, in 



* Diagnosis: Body tapering uniformly from head to caudal, depressed, its depth about 

 of its width (at base of pectorals), the latter 7 in length of body. Head 4i; a deep pit 

 behind occiput, with a longitudinal ridge in its bottom. Plates in the dorsal series 35 to 

 37; between occiput and first dorsal 6 (occasionally 7) pairs; between dorsals 5 (occasion- 

 ally 6); between venirals and anal 12 or 13 pairs; teeth numerous on jaws, vomer, and 

 palatines. One small barbel at tip of maxillary; gill membranes broadly joined to 

 isthmus, without free fold. Median rostral plate with a single upright spine; nasal 

 spines separated; supraocular spines small, sharp; 2 pairs of occipital in the form of low, 

 blunt tubercles. Color olivaceous, with 6 or 7 darker cross bars. 



