NO. 2096. 1\^EW ENTOMOSTRAVA FROM COLORADO— DODDH. 



101 



Fig. 6.— Diaptomus 

 arapahoensis. fifth 

 feet of male. x 82. 



at the tip and bears on its convex (inner) surface a row of small 



teeth. The inner one is more slender, tapers uniformly to a fine 



point, and is fl.nely setose. The endopodite nearly 



equals the exopodite in length and bears near the 



tip a few very small spines. (Fig. 6.) 



Length of female, 2.1 mm. Length of male, 1.7 



mm. These are the measurements in the lakes 



where they attain the greatest size. In one lake 



they were respectively 1.6 and 1.35 mm. 



I have found this species in four mountain lakes 



in Colorado at elevations of about 11,000 feet. 

 Three of these lakes, known locally as the Arap- 

 ahoe Lakes, are located just east of the Conti- 

 nental Divide a short dis- 

 tance from the railroad sta- 

 tion Corona, on Rollins Pass. 

 The fourth locality is a 

 lake about 12 miles farther 

 north. Diaptomus shoshone 

 Forbes is also foimd in each of these lakes. 

 Type-locality. — South Arapahoe Lake, Colo- 

 rado. 



Type.—U^lQ, Cat. No. 47878, ^ 

 U.S.N.M. Paratype, female, 

 Cat. No. 47878, U.S.N.M. 



DIAPTOMUS LINTONI Forbes. 



FIG 7.-DIAPT0MUS LINTONI. ^his spcclcs was collccted and 

 Last three segments of described by Forbes ^ from Yel- 



MALE EIGHT ANTENNA, SHOW- -i , "r)TT_ li- 1 



iNG THE TWO EXTREMES OF lowstonc Park where he found 

 THE APPENDAGE OF THE it " common lu lakcs aud pools." 



ANTEPENULTIMATE SEGMENT. i xl ' i. T- j. • !_ 



^ ij^s. Apparently it has not smce been 



collected until it appeared in 

 my collections from Colorado. During the summers 

 of 1908, '12, '13, and '14, I have found it as an impor- 

 tant part of the fauna of two lakes, known as Teller 

 Lakes, near the town of Tolland, Colorado, at an ele- 

 vation of 9,575 feet. Though collections were at the 

 same time made from a considerable number of other lakes in the 

 same region, the species was found only in these two lakes. Forbes 

 states that in Yellowstone Park it occurs commonly with D.slioshone. 

 The two lakes in which I have found the species are just about at the 

 lower altituduial range of B. shoshone in this region. In one of them it 

 forms a minor part of the fauna and in the other I have never found it. 



Fig. 8.— DiAPTOMua 

 LINTONI. Termi- 

 nal SEGMENTS OF 

 male RIGHT AN- 

 TENNA. Copied 

 from figure of 

 Forbes. 



1 S. A. Forbes, A preliminary report on the aquatic invertebrate fauna of the Yellowstone National Park, 

 Wyoming, and of the Flathead region of Montana. Bull. U. S. Fish Com., 1S91, pp. 207-258. 



