ORTALID^G — SYSTEMATIC DISTRIBUTION. 59 



between both authors, forbid us from giving Coquebert's name 

 the priority over Fabricius's. 



At the same place I have also observed how very distinct a 

 species Myennis fasciata is, with its Trypeta-like stature, its 

 low head and especially the very large distance between the ends 

 of the auxiliary "and of the first longitudinal vein; the latter 

 character especially is quite peculiar among the Ortalidse with 

 a bristly first longitudinal vein. 



Among the Ortalidse hitherto described, the following species, 

 as far as known to me, show a sufficient agreement, in their 

 characters, with Myennis fasciata to be considered as belonging 

 to the same circle of relationship: Trypeta ocellata Wied., from 

 the environs of Bahia, Brazil ; Ortalis obscura Wied., from 

 Brazil, Ortalis vau Say, and Platystoma annulipes Macq., the 

 two last from the United States. The numerous characters which 

 all these species share with Myennis fasciata, besides the already 

 mentioned peculiarities belonging to this species in particular, 

 are: 1, the unmetallic coloring of the body; 2, the comparatively 

 low, but rather broad head ; 3, the broad front; 4, the rounded, 

 more or less protruding eyes ; 5, the round, or very short rounded- 

 oval shape of the third antennal joint ; 6, the shortness of the more 

 or less concave face; 7, the small development of the clypeus; 8, 

 the comparatively large development of the chest ; 9, the protho- 

 racic bristle, represented by a very small hair only ; 10, the middle 

 of the thorax, which is beset with bristles upon its hind part only; 

 11, the convex scutellum, provided with four bristles; 12, the very 

 much abbreviated fifth segment of the female abdomen, which is 

 very often quite withdrawn under the preceding segment; 13, the 

 posterior angle of the anal cell, which is drawn out in a point, or 

 even in a lobe. 



Although the agreement in so many characters affords a dis- 

 tinct proof of the close relationship of these species, each of them 

 shows at the same time plastic differences of such an importance, 

 that one might be tempted to establish a separate genus for 

 almost every one of them. These differences principally consist 

 in the different shape of the wings, and in the different course 

 of their veins, while the rest of the organization shows a re- 

 markable agreement. 



In the shape of the wings two remarkable modifications are 

 worthy of notice, and may serve at some future time for a further 

 subdivision of this group. 



