DESCRIPTION OF THE SPECIES. 225 



the second posterior cell, reaches with its tip considerably beyond 

 the fourth longitudinal vein, and almost coalesces here with the 

 S-shaped hyaline band. The external costal cell also is hyaline, 

 with the exception of its basis, but has a more yellowish tinge 

 than the other hyaline spaees. Stigma rather long, almost imper- 

 ceptibly darker than its surroundings. Crossveins straight and 

 steep ; the third longitudinal vein distinctly bristly ; the end of 

 the fourth longitudinal vein turned forward ; the posterior end 

 of the anal cell drawn out in a very narrow, long lobe. 



Hab. Mexico (coll. Winthem). 



Observation. — The comparison of the description of Trypela 

 fraterculus and T. ludens shows the great resemblance of the 

 two species and an entirely satisfactory distinctive character in 

 the different length of the last abdominal segment. The females 

 of these species, which unfortunately I have not seen, will pro- 

 bably be easy to distinguish, if attention is paid to the size, which 

 is larger in T. ludens, to the somewhat broader cheeks, the 

 longer last abdominal segment of this species, and to the course 

 of the third and fourth longitudinal veins, which suddenly diverge 

 here, while their divergency in T. fraterculus is much more 

 gradual. In using the coloring for distinguishing the two species, 

 a certain caution is necessary here, as well as in the other species 

 of this group. 



6, T. tricincta n. sp. % . — Lutea, scutelli basi tribusque abdominis 

 fasciis nigris, alarum rivulis nigro-fuscis, apice venae longitudinalis 

 quartae recurvo. 



Clay-yellow; basis of tjie scutellura and three crossbands of the abdomen 

 black; the end of the fourth longitudinal vein somewhat curved for- 

 ward. Long. corp. 0.26; long. al. 0.2(3 — 0.27. 



Clay-yellow, more yellowish-red on the thoracic dorsum. 

 Head of the same color and shape as in the three preceding 

 species. In the middle of the thoracic dorsum there is a longi- 

 tudinal sulphur-yellow stripe, proceeding from the posterior mar- 

 gin ; it is rather broad posteriorly, gradually becomes narrower 

 anteriorly, and finally disappears near the anterior margin ; more- 

 over each posterior corner emits a conspicuous sulphur-yellow 

 stripe to the transverse suture ; the humeral callosity and a broad 

 longitudinal stripe reaching from it to the root of the wing and 

 then passing under the latter to the posterior part of the thorax, 

 15 



