220 riiiu KKDisas of rm: SMUtsAL mi shim. vouxx. 



ill t1i€i iimlo, bn>iul«Miiiiff a littlr iiiiti'riorly; fn»ntul costa faintly wider 

 tliiiii tJM' iiit(*rH|>a<'(' iM'twMM'ii tlic! eyes, cM|iial, (ailiiiu Just het'on> tii<^ 

 <'ly|KMis, fri'hiy siilcatr at and htdow tin* <mm'IIiis, punctate above; eyes 

 ratlicr I ii-|;e and rattier pnnninent, particiilariy in the male, halt' at4 

 loii^; a^ain a« tlie inlVaocular portion of tlie jjenae; antennae ( f ). l*rono- 

 tnni feebly eiilar^in^ on the ineta/.ona, the lateral lobes witii only 

 broken sijjns of a postociilar dark l»and on the prozona, the disk very 

 broadly convex, passing by a distinct rounded an^de, Ibrniin^ a feeble 

 hiteial carina, into the rounded sul)verti(;al lateral lol>es; median carina 

 distinct but slight on the meta/ona, siibobsolete or obsolete on the pro- 

 zona; front niar<:in truncate, hind inarj^in strongly obtnsan^iilate; 

 ])ro/.ona feebly transverse, hut litth» lonj^'^er than tlie densely and not 

 very finely punctate iiieta/ona. I'rosternal spine iiKxbMatelylonj;, rather 

 slender, at least in the male, c(Uiical, erect ; interspace between ineso- 

 steinal lobes nearly twice as long: 5»'** broad (mah*) or quadrate (female). 

 Tej;inina as loiij;' as or sli;»:htly lonjier than the luonotiiin, ovate, moder- 

 ately broa<l, atting^ent or overlapping,', api<'ally acuminate. Fore and 

 middle femora a little tumid in the mr.le; hind femora not very loii;,% 

 Hoinewhat compressed, uniform lijjht testaceous, with fuscous pcni<'iilar 

 arc; hind tihiae li^ht testaceous, the apical half of the spines black, nine 

 to ten in number in the outer scries. Extremity of male abdomen 

 hardly clavate, a little recurved, the supraanal plate trian<i:ular, with 

 acutan;;ulate apex, the surface nearly plane, except that it sweeps uj) to 

 the sharp, elevated, and upically united suluuediaii ridges inclosin^j a 

 very narrow and deep median sulcus, which crosses two thirds of the 

 l)late; funiila consistin^f of a ])air of apiiroximate, small, trianjjular 

 denticulations, no longer than the last dorsal segment, overlying the 

 ridges (d" the supraanal plate; cerci S'nall, subfalciform. tapi'ring to two- 

 thirils the basal width on proximal half, beyond eipial, bent a little 

 inward and curved upward, exteriorly sulcate, apically rounded, ininh 

 shorter than the supraanal plate; subgenital i)late small, feebly sub- 

 ccmical, projecting slightly, the apical margin rising very feebly to an 

 obscure apical tubercle, and as seen from above with a parabolic curve, 

 entire. 



Length of body, male, 14 mm., female, 20 mm.; togmina. male, 3.5 mm., 

 female, 5.5 mm.; hind femora, female, 12 mm. 



One male, 1 female. Cape St. Lucas, Lower C'jilifornia, J. Xantus. 

 The single pair are somewhat broken and have been bleached in alcohol, 

 so that the colors of the above description will have to be revised with 

 fresh material. 



12. DAWSONI SEllIES. 



This group is composed of rather heterogeneous material if the ma- 

 cropterous forms alone are considered, and is even more loosely coin- 

 l»acted when the brachypterous species are mingled with them. In 

 size they range from rather small to medium. A single species is 

 dimori)hic, being both brachypterous and macropterous. 



