372 C. R. OSTEN SACKKN'S PRODROME 



j Body altoo;ethcr gray 01- l)l;uki.sh 24. plangens Wied- ' 



I Body more or k'ss marked with yellow 18. 



[Face black, with the usual stripes of iulvous i)ollen 14. frigidus n. sp. ^'''^ 



I Face ferruginous in the middle 19. 



r A|)ical spot l.irge, reaching beyond the second submarginal cell, and invading the first posterior . 20. 



' 1 The ajiical .sjiot does not reach beyond the second submarginal cell 22. 



["The ]iy;dine s]iace, between the cro.ssband and the apical spot, is confined to a sni;ill triniigle in the ^^ 



20. \ second and third posterior cells 17. moechus ' n. sp. ■^ 



[The hyaline space, etc., reaches across the first j)ostcrior cell 21. 



fAljihinien with a broad, yellow, longitudinal stripe in the middle, enclosed between two blackish 



21. \ stripes 16. univittatus Macq. ^ „ 



I Abdomen brown, with three brownish-yellow, often indistinct longitudinal stripes 18. morosus n. sp. ~^ 



r Abdomen yellow, with four black stripes 23. 



OO 1 *' * 



23. 



I Abdomen black, yellow on the sides, and witii yellow triangles on the segments . . 13. indus n. sp.'^ 



Frontal tubercle and scutelhim reddish 19. vittatUS Wied."^ '^/^ 



Frontal tubercle black ; scutellum at the base, more or less blackish 20. StriatUS n. sp. ^'^ A 



DESCRIPTION OF THE SPECIES. 



A. The apical portion of the wing, bejonil the crossband, is h3'ahne, without any dis- 

 tinct brown spot or brown border. 



1. Chrysops atiopos n. sp. 



?C/mjso2}s (Jivisns Walker, List, etc., I, p. 204. 



? . Altogether black, wings tinged with black, except the apex, which is hyaline. 

 Lengtli, 9-10 mm. 



Female. Altogether black ; a large, shining l:)lack, oljtriangiilar surface occupies almost 

 the whole face, showing each side a maniiniforni protu1)erance ; streaks of fulvous pollen be- 

 tween this triangle and the black cheeks ; pollen of the same color forms a narrow border 

 alono- the facial orbit, round the root of the antennte and on the sides of the front ; the 

 black, shining, frontal callosity is separated from the vertex Ijy an opaque, brownish-polli- 

 nose crossband. Palpi black, brownish on the inside. Antennte black, comparatively long, 

 the first and second joints being longer than usuiil ; the first somewhat incrassate. Thorax 

 clothed with a very thin chocolate-brown pollen, hardly concealing the shining black color 

 beneath ; it is more dense anteriorly, where it forms two indistinct lines, abbreviated poste- 

 riorly, and more visiljje from a side view; (this thoracic pollen is very easily rubbed off). 

 Pleurai brownish. Abdomen with scattered whitish hairs toward the tip. First joint of mid- 

 dle and hind tarsi yellowish, except the tip, which is black ; root of second joint likewise 

 pale. Apical tliird of the wings hyaline ; the remainder black, wliich color is most saturate 

 along the costa ; anal cell and the whole anal angle, grayish. The veins in the hyaline, ap- 

 ical portion of the wing are yellowish, especially the costal vein. 



Ilab. Florida (Wekiva River, in March, Prof J. Wyman ; Indian River, E. Palmer). 

 Eighteen female specimens. 



' This is the hypothetical female of C. mocchus <i , described below. 



