64 



BULLETIN OF THE BUREAU OF FISHERIES. 



Leucidlus, new genus of Cyprinidce. Type Leucidius pectinifer, new species. 



Teeth 5-5 ; slightly hooked, high and slender, the grinding surface rather narrow ; base of arch long and 

 slender, the limbs somewhat cylindrical. Gillrakers 29 to 36, the usual number being 31 to 34; closely 

 apposed, long, slender, sharply pointed, almost straight; the inner edge with short, blunt papillse; those 

 at both ends of arch relatively long and well developed, the whole suggesting a fine-toothed comb. 

 Pseudobranchiae present; no barbels; premaxillary protractile; lateral line complete; peritoneum dusky; 

 alimentary canal short; air bladder extending the entire length of the visceral cavity. Dorsals inserted 

 almost directly above ventrals; dorsal and anal short. Scales large and regular; lateral line complete. 



Leucidius is a lake minnow. It takes its place at once among an array of peculiar western genera, 

 Pogonichthys , Myhpharodon, Orthodon, Lavinia, Mylocheilus, Gila, Meda, Tiaroga, and others. 



Leucidius pectinifer, new species. Lake minnow. 



This species has long escaped notice by reason of its close resemblance to Siphateles obesus. Pre- 

 served specimens of both species look remarkably alike until those of greater length than 8 or 10 inches 

 are compared, when S. obesus begins to appear deeper and shows a more or less definite nuchal hump. 

 In life L. pectinifer is lighter in color, whitish and silvery, while S. obesus is bronzy or brassy. Gape " 

 apparently recognized both species in Pyramid Lake, for he says, when speaking of S. obesus (L. oliva- 

 ceus), "This and the smaller L. dimidiatus swim in schools in the lake, as may be seen from the elevated 



Fig. 4. — Siphateles obesus. Winnemucca Lake, Nev.b 



Fin. 5. — Leucidius pectinifer. Pyramid Lake, Nev. 



road along the rocky shores, rippling the surface like a gust of wind." However, Cope's descriptions of 

 both L. dimidiatus and L. olivaceus are based on specimens of 5. obesus, as the types show.<^ Examples 

 of Leucidius pectinifer were long ago collected with those of S. obesus in Washoe Lake and recorded as 

 the latter species. The same oversight was later made in a collection from Eagle Lake. Cleaned 

 pharyngeals of this species from the latter place, labeled L. olivaceus, led to the erroneous statement 

 that the teeth of L. olivaceus numbered 5-5. "^ Leucidius pectinifer might on superficial examination 

 be confused with Richardsonius microdon, but a glance at the gillrakers will serve to identify it 

 among other western minnows. (See fig. 5.) 



Description of type no. 76304, United States National Museum, a female specimen measuring 237 

 millimeters, from The Willows, Pyramid Lake, Nev., June 2, 1913. (See fig. 6.) 



Head 3.7 in length to base of caudal; depth 3.6; depth caudal peduncle 9.3; eye 5.3 in head; snout 

 3.3; maxillary 3.7; height dorsal 6 in length; anal 7.3; length pectoral 6.7; ventral 6.7; caudal 4; 

 dorsal rays 8; anal 8; scales lateral series 57; between lateral line and back 13; between lateral line 

 and ventral fin 8; between occiput and dorsal 30. 



Depth of body somewhat less than twice its width, the deepest part being below origin of dorsal fin. 

 Dorsal contour rather angular, sloping forward from origin of dorsal to tip of snout, this part of the outline 

 somewhat convex, and backward to caudal peduncle, the outline slightly concave. Ventral contour 



a Proceedings, Academy Natural Sciences, Philadelphia, 1883, p. 145. 

 ^ See p. 60 for description of species. 



<; When at the Academy ot Natural Sciences in Philadelphia, Mr. Henry W. Fowler kindly allowed the writer to examine 

 the types of both species. 

 ' d Bulletin, Bureau Fisheries, vol. xxvn. 1907, p. 87. 



