58 



BUI.LETIN OF THE BUREAU OF FISHERIES. 



Measurements of Richardsonius egregius — Continued. 

 STAR CREEK, NEAR DEETH. NEV. 



Length of body tnm 



Length head 



Depth body 



Depth caudal peduncle 



Length caudal peduncle 



Length snout 



Diameter eye 



Interorbital width , 



Depth head 



Snout to occiput , 



Snout to dorsal 



Snout to ventral 



Length base of dorsal , 



Length base of anal , 



Height dorsal 



Height anal , 



I^ength pectoral , 



Length ventral , 



Length caudal 



Dorsal rays , 



Anal rays 



Scales lateral line 



Scales above lateral line 



Scales below lateral line 



Scales before dorsal 



9 

 0.36 



• 27 



• II 



• 22 

 •075 



• 06s 

 •09 

 .18 



• 30 



•55 

 •51 

 .10 

 .135 



.19 

 .18 



.20 



.15 



.24 



8 



8 



55 



13 



7 



33 



Cockerel and Allison 1 employ structural scale characters to distinguish between this and other 

 species of the genus. Their conclusions, apparently based on few specimens, will not stand the test of 

 this species, for the scale radii are found to number from 6 to 2 1 and the number of circuli depends upon 

 the age of the individual from which the scale was taken. The variable character of the peritoneum 

 pigment has been described. The annexed table will exhibit the number of radii possessed by a few 

 scales taken from between the lateral line and dorsal fin of specimens of R. egregius selected at random 

 from several localities. 



Richardsonius microdon, new species. Tahoe shiner. 



This species will not be confused with Richardsonius egregius, another member of the genus found 

 in the basin, for it has a much more robust form, a heavier caudal peduncle, a longer snout, and a larger 

 mouth. In general appearance it more closely resembles Siphateles obesus and Leucidius pectinifer, 

 having the same general color and shape, except that the body is a little more slender, the head some- 

 what longer, the snout more pointed, the mouth larger, and the posterior border of the opercle more 

 angular. From these it may be told at a glance by the posterior position of its dorsal fin. The species 

 is not distinguished from either 5. obesus or L. pectinifer by the local fishermen, but it is not mistaken 

 for R. egregius. 



Description of type. No. 75652 United States National Museum, a female measuring 140 mm., 

 from Lake Tahoe, near Tahoe City, Cal., June 27, igii: 



a Proceedings. Biological Society, Washington, vol. xxn, p. 160. 



Radii few (8 or 9) ; lateral circuli about 30 on each side; peritoneum silvery, nearly as in neogaeus, but with more diffuse, large 

 brownish spots. Willow Creek, Honey Lake Basin, Cal. L. egregius (Girard). 



Radii more numerous (lo to 13); peritoneum silver, with black spots on upper part. Eagle Lakes, Me. L. neogaeus (Cope). 



Radii most numerous (15 to 20); but only about 10 complete; circuli about 20 on each side: peritoneum silver, with many 

 spots, mostly reddish brown, some black, none large, the general effect not dark, though tlie spots are numerous. Cemetery. 

 Creek, Watertown, N. Y. L. mcrgarita (Cope). 



