JordcDi and Evcnnann. — Fishes of North Amaica. 



2085 



775. ODONTOPYXIS, Lockiugtou. 



OdontovyxiB, Lockinqton, Troc. U. S. Niit.Miis., 11, 1879, 328 {tris2)inosus). 



Body very sleuder, depressed, taperiug uuiformly from head to caudal ; 

 head 3|- to ii, the width of body 6 to 7, depth 6 to 8 in k-ugth of body. A 

 deep pit behind occiput with a kmgitudinal ridge iuits bottom; plates in 

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

 second; teeth numerous on jaws, 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, {odovi, tooth; Ttv^ii, has..) 



2427. ODONTOPYXIS TRISPIXOSUS,-^^ Lockington. 



B. 6; 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 cajca 5 to 7 (1 or 2 very 

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

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

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

 trolateral series ; aboiit 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 on 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 iV of i**^ width, the latter 7 in length of body ; 

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

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

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

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

 l)ut, 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 

 sul>orbital 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 ixniformlv from head to caudal, depressed, its deptli about f 

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

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

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

 ally 6); between ventrals 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 tree told. 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. 



