GEOLOGICAL SURVEY OF THE TERRITOEIES. 443 



furrows of the face seen only in dried specimens, the face being regu- 

 larly convex. 



Z>. trilineatus, Thos. 



Syn., ThamnotHzon trillineatus, Thos. 



This species probably belongs here^ as it is closely allied to the pre- 

 ceding. I have not met with it west of the dividing range, but have 

 traced it up the eastern slope nearly to the summit at South Pass, 

 Wyoming. 



JjOCiistafiiUginosayTiOY. sp. 



Afale. — Elytra and wings very long, nearly twice the length of the 

 body. Wings dark fuscous, with short pellucid bands between the 

 nerves. 



Occiput is divided into three obtusely rounded, longitudinal ridges, 

 the middle the broadest 5 the tubercle between the eyes compressed 

 laterally, and sulcate. Pronotum short, lateral carinse distinct on 

 the posterior lobe; the second transverse impression bends backward 

 OD the dorsum, so as to form an acute angle; front sub-truncate; 

 posterior extremety obtusely rounded ; the entering angle of the i)0S- 

 terior margin situated a little below the humerus, and is simply a 

 rounded notch ; the lower margin of the sides rounded, in a somewhat 

 :Semi- circular form, from the anterior angle to the notch before men- 

 tioned. Elytra very long, nearly equal to Wice the length of the body, 

 ^f moderate width, margins parallel, apex round. Wings nearly as 

 long as the elytra ; the nervules very minute, almost imperceptible, ex- 

 cept near the inner margin, where they are a little more prominent. 

 The superanal plate is divided nearly to its base, the two lobes pro- 

 longed into pointed processes reaching the tix)S of the cerci ; the cerci 

 ^ery stout, rounded exteriorly, somewhat carinated internally, apex 

 rounded externally, internally there is a notch with a spine each side of 

 it; subanal plate triangular at the apex, with two converging carinse 

 beneath, which terminate in the cylindrical appendages. All the 

 femora furnished with two rows of s^nnes, irregular, and but few on 

 some of the carinse. Anterior tibise with a single row of two or three 

 spines in front ; the middle tibise with two rows above, five in each, 

 opposite ; posterior tibiae with two rows beneath. The prosternal s^nnes 

 sharp ; the lateral angles of the meso and meta-sternum are also pro- 

 duced into dull spines, the latter the most obtuse. Spine of the anterior 

 coxa broad at base, i^ointed at tlie apex. 



Color J (dried.) — Fuliginous. Labrum pale yellow; a bright-yellow 

 spot between the eyes, at the base of the tubercle ; face dull yellow, 

 variegated with dark brown ; joints of the maxillary palpi fuscous at 

 the base and pale at the tip ; antennae pale testaceous, the first and sec- 

 ond joints fuscous. Pronotum palest on the dorsum ; the upper poster- ^ 

 ior i^arts of the sides darkest. Elytra semi-pellucid, with a fuliginous ' 

 shatle, varied with darker spots, those along the middle field largest; 

 stridulathig organ scarcely diifering in color from the other parts. 

 Wings fuligiuous throughout, varied only by short serai-pellucid bands 

 reaching from one nerve to another, always situated between the nerv- 

 ules. Legs fuscous, the tibiae palest. Female, unknown. 



Dimensions. — Length of the body to tip of the cerci, 1.26 inches; 

 cerci, .lOiuch; elytra, 2.28 inches; posterior femora, L2G inches; pos- 

 terior tibiae, 1.33 inches. 



