PEOMACHUS. 193 



P. philadelphicus (syn. P. bastardi, Macq.). Wiedemann's P. quadratus, 2 , must be a 

 large species; the size given is 14 lines, while the same author's measurement of 

 P. vertebratus, Say, $ , is only 12 lines. Schiner (Verh. z.-b. Ges. Wien, 1866, p. 688), 

 in speaking of Wiedemann's type of P. quadratus, says : " a magnificent species " (eine 

 prachtvolle Art). These remarks are not applicable to P. bastardi, $ ; it is neither 

 " magnificent," nor 14 Rhenish lines (about 31 millim.) long. 



1. Promachus ductus. 



Promachus cinctus, Bellardi, Saggio &c. ii. p. 25, t. 2. f . 2 \ 



Hab. Mexico {Salle x ) ; Guatemala (Champion) ; Nicaeagua, Chontales (Janson). 



Bellardi describes both sexes. I have two females which I have compared with 

 Bellardi's types and take to be the same species, although I perceive some differences, 

 principally in the colour of the hairs, which seems to be variable. On the facial 

 prominence there are several strong fulvous bristles ; on the oral margin on each side 

 a few black bristles, and on the upper part of the front a sparse tuft of weak black 

 hairs (in Bellardi's specimen they are strongly mixed with yellow). The first abdominal 

 segment and the base of the second segment are beset, in one of my specimens, with 

 soft, erect fulvous hairs ; in the other, and in Bellardi's examples also, these hairs are 

 whiter ; there are besides, on each side of the first segment, some black macrochsetae. 

 Halteres brownish-red. The wings have a distinct brownish tinge ; the shadow in the 

 first submarginal cell large. 



2. Promachus ? 



Female. Bristles on the facial prominence black, mixed with yellowish- white ones, the latter prevailing on the 

 lower half; cheeks with dense whitish hair. Thoracic dorsum blackish-grey, with the usual grey design ; 

 the median line between the two dorso-central stripes nearly obsolete ; scutellum with yellowish hairs and 

 black bristles. Abdominal segments 2-5 with yellowish-grey pollinose rectangular triangles on the sides 

 (the inner acute angle of the triangle meeting the corresponding angle on the opposite side, the hypothe- 

 nuse distinctly concave and leaving a semicircular black space in the middle of each segment) ; the venter 

 also yellowish-grey ; the same segments clothed with sparse, erect, yellowish hairs on the back, and with 

 denser hairs of the same colour on the venter ; the 6th and the following segments black, narrow, com- 

 pressed. Femora black, with black spines and woolly yellowish-white hairs ; tibiae reddish-yellow, with 

 black tips ; tarsi black. Halteres pale reddish-yellow. Wings with a slight greyish tinge ; more hyaline 

 along the proximal two thirds of the costa ; the shadow in the first submarginal cell comparatively short, 

 narrow, club-shaped. 



Length to the end of the fifth abdominal segment, 16 millim. ; to the end of the ovipositor, about 22 millim. 



Hab. Mexico, Northern Sonora (Morrison). Two females. 



The Mexican P. trapezoidalis, Bellardi (Saggio &c. ii. p. 28, t. 2. f. 4) is not unlike 

 this species ; but it is impossible to identify it from the description. 



biol. cen"tr.-amee., Dipt., March 1887. 2 c 



