56 D1PTERA. 



bifurcation of the third vein and on the cross-veins closing the discal cell are not a con- 

 stant character ; in one of my specimens they are wanting. Two females. 



N.B. Although Walker's two descriptions are earlier, they are too unsatisfac- 

 tory to be taken into consideration ; that both refer to albonotatus is proved by the 

 description of the front tibiae (for oculus : fore shanks pale tawny, with black tips ; for 

 bipartitus : legs ferruginous, fore thighs rather darker, fore feet and tips of fore shanks 

 piceous). At the same time, Walker does not mention the closed first posterior 

 cell nor the appendiculated fork ; instead of which he breaks up the species in two, with 

 an imaginary difference in the length of the abdomen. I have seen the types in the 

 British Museum. 



I have a single female specimen (Bugaba, Panama, Champion) with the same charac- 

 teristic dark spot, encircled with white, on the scutellum, but easily distinguished by 

 the broadly open first posterior cell, the unappendiculated fork of the third vein, and 

 the uniformly black front tibiae. All these characters are those of T. defilippii, 

 Bellardi, Saggio &c. i. p. 57 ; nevertheless the Panama insect is not that species. The 

 true T. defilippii is much larger (23-24 millim., while the specimen from Bugaba is 

 about 14 millim.), and has the body and wings much browner. 



12. Tabanus mexicanus. 



Tabanus mexicanus (Linn.), Wiedem. Aussereur. zweifl. Ins. i. p. 147 ; Bellardi, Saggio &c. i. 

 p. 59 x (for the synonymy, see my Catal. N. A. Dipt. 1878, p. 59). 

 Hab. Southeen United States. — Mexico 1 ; British Honduras (Blancaneaux, two 

 females). — South America. 



13. Tabanus lineola. 



Tabanus lineola (Fabr.), O. Sacken, Prodr. of N. Am. Tabanidse, p. 448 * (where the synonymy will 



be found) . 

 Tabanus trilineatus (Latr.?), Bellardi, Saggio &c. i. p. 63 2 . 



Hab. United States 1 .— Mexico 2 (Salle, Sumichrast); Nicaragua, Chontales (Janson). 

 — South America. 



I have seen the type of T. trilineatus, Bellardi, in Turin. 



A common species in the United States. 



Tabanus commiwtus, Walker, Trans. Ent. Soc. Lond. n. ser. v, p. 273, from Mexico, 

 is represented in the British Museum by a single badly-preserved female specimen 

 which belongs either to T. lineola or to some closely-allied species of that difficult group. 

 This is one of those cases where a description represents merely a specimen, and not a 

 species, and for this reason the name would better be suppressed. 



STIBASOMA. 



Stibasoma, Schiner, Verh. zool.-bot. Ges. Wien, xvii. p. 310 (1867) ; Reise d. Novara, Zool. iii. 

 Abth. 1, p. 93. 



