I 



NO. 1310. yORTII AMERICAN TlIYSANOI'TEliA— HINDS. 211 



larger than the head, of equal breadth with it, the whole thorax shaped 

 as in Pah^othrips. Onh' fragments of the wings remain, sufficient to 

 render it prol)a])le that they agree well with the character of the group 

 to which Melanothrips and ^l^^olothrips belong. The legs resemble 

 those of PaUeothrips, but are slender and appear to be rather profusely 

 supplied with hairs. The abdomen differs considerably in the two 

 specimens referred to this genus. In one it is very ])roadly fusiform, 

 the tip a little produced, nine joints visible, the apical furnished with 

 a few hairs, and bluntly rounded at the tip; the other has the sides 

 equal, the apex not at all produced, but very broadly rounded, only 

 seven or eight joints vaguely definable. 

 "A single species is known." 



LITHADOTHRIPS VETUSTA Scudder. 



LUhadothrips vetusta Scudder, Bull. U. S. Geol. Geog. Surv. Terr., I, 1875, p. 222; 

 Kept. U. S. Geol. Surv. Terr., XIII, 1890, p. 372. 



"The specimens, both of which represent the upper surface of the 

 body with fragments and vague impressions of the members, are too 

 poorh^ preserved to add anything to the al)ove description of their 

 generic features, excepting the following measurements: 



'^ First s2)eciinen. — Length of body 1.76 nun., of antenna' 0.6 nmi., 

 of thorax 0.6 mm., of abdomen 0.87 mm.; breadth of head 0.!^8 nun., 

 of thorax 0.62 mm., of abdomen 0.56 nmi.; length of fore femora, 0.37 

 nun. ?; breadth of same, 0.11 mm.; length of hind femora, 0.42 mm.; 

 breadth of same, 0.13 mm. 



^^ Second specivien . — Length of bod}^ l.lHi mm., of antennae 0.76 nun., 

 of thorax 0.66 mm., of abdomen 1.10 mm. ; breadth of head 0.38 mm., 

 of thorax 0.5*J nun., of abdomen 0.61> mm. 



" Fossil Canyon, White River, Utah. Two specimens, W. Denton." 



Genus PAL^EOTHRIPS Scudder. 

 Pahrothrips i^LTDUKR, Bull. U.S. Geol. Geog. Surv. Terr., I, 1875, i>. 222. 



''This genus is allied to ^l^^olothrips Haliday. The head is small, 

 globo.se; eyes rounded, nmch smaller than in Lithadothrips; antennjfi 

 slender, fully as long as the thorax, not more than seven jointed, the 

 joints cylindrical, subequal. Prothorax considerably larger than the 

 head, the thorax as a whole very large, stout, and tumid; fore femora 

 very stout, scarcely more than twice as long as broad; fore tibipe also 

 stout, a little longer than the femora; the other legs are moderately 

 stout, long, reaching )ie3"ond the tip of the abdomen, with a few scat- 

 tered, rather short, spinous hairs; the hind tarsi three jointed, the last 

 joint smaller than the others, and altogether two-sevenths the length 

 of the tibia?. Fore wings unusually broad, broadest apicall}^, where 

 their breadth more than equals one-fourth of their entire length, pro- 

 vided with two longitudinal veins, dividing the disk into three nearly 



