246 bulletin 47, United States National Museum. 



of Nevada (LakeLahontan,) andpulverulentus ( =parovanus),fTom the basin 

 of Utah (Lake Bonneville). In general the fish faunae of the basins of 

 Nevada and Utah are entirely distinct. But we know of no constant char- 

 acters on which a division of this species can be maintained, (symmetri- 

 cus, symmetrical ; it being supposed to differ from Pogonichthys macrolepi- 

 dotus in the symmetrical tail.) 



Pogonichthys symmetric^,* BAIRD & GIRARD, Proc.Ac. Nat. Sci. Phila., 1854, 136, Fort Miller, 



San Joaquin Valley. (4% inches long). 

 Algansea formosa, GIRAHD, Proc. Ac. Nat. Sci. Phila., 1856, 183, Merced and Mohave rivers. 



(5% inches). (Type, Nos. 2754 and 2755. Coll. A. L. Heermann.) 

 Algansea obesa,^ GIRARD, Proc. Ac. Nat. Sci. Phila., 1856, 183, Humboldt River; GIRARD, Pac. 



R. R. Surv. , x, 239, 1858. (Type, No. 2752. Coll. Lieut. Beckwith . ) 

 Myloleucus pnlverulenlus,l COPE, Hayden's Geol. Surv. Montana for 1871, 475, 1872, 'Warm 



Springs, Utah. (Scales 13-58-9.) 

 Myloleucus parovanus, COPE, Proc. Amer. Philos. Soc. Phila., 1874, 136, Beaver River, Utah ; 



COPE, Zool. Wheeler Surv., v, 669, 1875, (1876); COPE, Proc. Ac. Nat. Sci. Phila., 1883, 143. 

 Leucosomus symmetricus, GUNTHER, Cat., vii, 267, 1868. 

 Ceratichlhys symmetricus, JORDAN & GILBERT, Synopsis, 213, 1883. 

 Leuciscus formosus, GUNTHER, Cat., vu,245, 1868. 



Leucos formosa, JORDAN & HENSHAW, Report Chief Engineers, App. NN, 193, 1878. 

 Leu.cnsform.oms, JORDAN & GILBERT, Synopsis, 244, 1883. 

 Leuciscus obesus, GUNTHER, Cat., vii, 244, 1868. 



Leucos obesus, JORDAN & HENSHAW, Report Chief Engineers, App. NN, 192, 1878. 

 Leucus obesus, JORDAN & GILBERT, Synopsis, 245, 1883. 



* The type of Pogonichthys symmetricus has no barbel; the teeth 4-5; the head 4 in length; the 

 depth 4%; scales 9-53-6. It seems to be the same species as Algamea formosa, which has scales 

 10-57-7. ' The type specimen of Algamea formosa (No. 196), from Merced River, is 5% inches long. 

 Head 3{j; depth (eviscerated) 4%. Eye 5, 1% in snout. Snout 4 in head. Mouth terminal, 

 oblique, about as in No. 193, but the lower jaw slightly included. Maxillary not reaching eye. 

 D. 8; A. 8. Scales 10-57-7. Another of these specimens has the snout shorter and a little more 

 pointed. Scales 11-57-7. The type from Mojave River (No. 197), 4% inches long, has head 3%; 

 depth 4. Eye 4%, shorter than snout, which is pointed, 4 in head. Mouth oblique; lower jaw 

 slightly projecting. D. 8; A. 8. Scales 11-51-7. This form from Mojave Riverseemsto cor- 

 respond with specimens from tributaries of Owen Lake, Inyo County, California. These differ 

 from typical symmetricus in the form of the head, agreeing in this respect with the types of obesus 

 and parovanus. The snout in the Inyo County specimens is shorter, barely equal to the eye and 

 not convex as in symmetricus; mouth very oblique; dorsal over ventrals. Scales 10-55-6. These 

 may be the same as It. parovanus, the figure of which shows this form of mouth. Rntilus parovanus 

 is thus described: Body rather stout; muzzle short, conical; mouth very broad, the maxillary 

 reaching front of orbit; profile gently arched; eye large, 3 in head, equal to interorbital width; 

 pectorals reaching little more than half way to ventrals; the latter just to vent. Translucent, 

 with a plumbeous lateral band. Ventrals and pectorals dusky; dorsal and caudal shaded with 

 dark. Head 3%; depth 4%. D. 9; A. 8. Scales 10-48-5; teeth 4-5. Length 12 inches. (Cope.) 

 Beaver River, Utah, a tributary of Sevier River. 



f R. obesus is apparently identical with Rutilus symmetricus. Body stout ; head short; snout 

 4 in head, moderately pointed, not much convex. Mouth oblique, lower jaw not projecting; 

 maxillary not reaching eye. Head 3%; depth 3%; eye 5, 1% in snout. Scales 12-57-8. Length 

 6% inches. Here described from notes on Girard's type (No. 194, U. S. Nat. Mus.) from Hum- 

 boldt River. 



Another of Girard's specimens (No. 193, U. S. Nat. Mus.) from Humboldt River is 6% inches 

 long. Head 3%; depth 3%. Eye 5 in head, \% in snout, which is 3| in head. Mouth terminal, 

 oblique, the lower jaw scarcely projecting; maxillary not reaching eye; snout pointed. Scales 

 14-58-8. D. 9; A. 8. 



Another* specimen from Nevada, 5 inches long, has snout a little longer than eye; scales 11- 

 56-6; depth 4. Still another, 8% inches long, from "Camp 21, Nevada," has scales 12-54-6; 

 snout not decurved; eye 1% in snout. Of specimens from Truckee River, one has a convex snout 

 very pronounced; another the snout slightly convex, the two others not convex at all. 



% Myloleucus pulverulentus is thus described: Form stout; head short, muzzle not decurved; 

 mouth terminal, slightly descending, the maxillary bone nearly attaining the anterior line of 

 the orbit. Head 3.75 times in length, exclusive of caudal; depth 3% times. Eye 4.2 in head, 

 1 in muzzle. Preorbital bone deeper than long. Scales 13-58-9. Radii: D. I, 9; A. II, 7. Caudal 

 well forked. Length 3% inches. A dark plumbeous band extends from the origin of the lateral 

 line above to the caudal peduncle and on it to the caudal fin; below this the color is silvery, 

 thickly dusted with black dots; above it is an olive-yellow band, then a dark dorsal region, all 

 dusted; sides of head silvery, dusted; fins unspotted. Numerous specimens from the Warm 

 Springs, Utah. 



