152 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY - IV. 



>nueh compressed, lancet-shaped, erect, nearly straight. Upper limb 

 of the phaiyngeal bone very broad and concave, separated by a deep 

 Hotcli from (he dentigerous portion, the bone thin and brittle. Intes- 

 tinal canal elongate, about 7 times the length of the fish; peritoneum 

 black. Scales small. Lateral line present. Dorsal fin opposite veti- 

 trals. Basal rays of caudal largely developed. Anal basis short. 

 Pseudobranchia- none. Gill-rakers moderate, clavate, the inner edge 

 fringed. Size large. This genus is related to Chondrotitoma, differing 

 chielly in the absence of pseudobrauchiae and of the horny inaudibular 

 plate. ("iiOiis, straight ; oowv, tooth.) 



. O. inierolcpidotus (Ayres) Grd. 



I'.ody elongate, llead moderate; the snout very broad; eye small, 

 about half the length of the snout. Mouth terminal, somewhat oblique, 

 broad, the maxillary not extending to the eye. Upper head of surface. 

 flattish, with two bony ridges. Fins rather large; the caudal strong. 

 Coloration plain. Lateral line decurved. Head 4; depth 4. D. I); 

 A. s ; scales 21-105-12 ; Vert. 24 + 20. Teeth C-G or G-5, formed much 

 as in <'<nni>n*tnma, but longer. Size large. L. 12 inches, llivers of 

 California; Great Basin of Utah (Yarrou-). 



(Ctlx iniiToli'jndola Ayres, Proc. Cal. Acad. Nat. Sci. i, '21, 155; Girard, U. S. Par. 

 R. R. Surv. Fish. 237, fig.; Giintker, vii, 1^75.) 



74. LAVINIA Girard. 



(Girard, Pmr. Acad. Nat. Sci. Pbila. 1854,1:57: type Lavinia et'ilicauda B. & G.) 



Body ellii>tical, elevated, moderately compressed, rapidly contracted 

 to the slender caudal peduncle. Head small, conical. Mouth mod- 

 erate, terminal, oblique; the lower jaw included. Scales moderate, 

 not closely imbricated, the exposed surfaces somewhat hexagonal. 

 Lateral line decurved, complete. Belly behind veutrals entirely scaled. 

 Dorsal I'm \vell behind ventrals, its last ray just in front of the begin- 

 ning of the anal, which is rather elongate. Caudal tin little forked, its 

 rudimentary basal rays much increased in number and very strong. 

 intestinal canal elongate. .". limes the total length of the lish; pe- 

 ritoneum dark. Teeth !-."> or .">-,"), scarcely hooked, cultriform, with 

 rather broad but shallow grinding surface, the largest standing up 

 well abo\e the surface of the bone. Gill-rakers rather long and slen- 

 der; psendobranchiic large. Si/e large. ( l,<irini((, a classical name, 

 without special application to these fishes.) 



