18 DIPTERA. 



is black or brown, shining, with some ill-defined lighter shades along the sutures ; metanotum brown in 

 the middle, yellow on the sides, shining ; scutellum dark brown or black. Abdomen black, with some 

 yellow on the sides of the two or three basal segments; lower portion of the male genitals brown, the 

 upper appendages yellow ; in the female the eighth segment, as well as the ovipositor, ferruginous. 

 Halteres yellowish-brown, the tip bright yellow in the male. Coxae dark brown ; femora brownish-yellow, 

 darker at the tip ; tibiae and tarsi brownish. Wings with a pale yellowish-brown tinge, more yellow in the 

 costal cells ; stigma pale brown ; second posterior cell subsessile, attenuated at the base, the contact some- 

 times punctiform. 

 Length : tf , 9-10 millim. ; $ , 11-12 millim. 



Hab. Costa Rica, Rio Sucio, Irazu (Rogers). A male and a female. 



This species is not unlike P. nigrolutea in general appearance, but is easily distin- 

 guished by the absence of an opaque spot on the lateral thoracic stripes, by the more 

 uniformly dark pleurae, the brown coxae, &c. 



5. Pachyrrhina ferruginea. 



Tipula ferruginea, Fabr. Syst. Antl. pp. 28, 29. 



Pachyrrhina ferruginea, Wiedemann, Aussereur. zweifl. Ins. i. p. 53; O. Sacken, Western Diptera, 



p. 211. 

 Pachyrrhina quadrilineata, Macq. Dipt. Ex. i. p. 50 (teste O. Sack.). 

 Pachyrrhina proxima, Bellardi, Saggio &c. i. p. 9 l (teste O. Sack.). 



Hab. United States and Bkitish North American possessions, common. — Mexico x , 

 Ciudad in Durango (Forrer). 



This species varies in the intensity of the brown borders of the thoracic stripes and 

 of the dark abdominal triangles ; both disappear altogether in some specimens. 



I have compared the types of P. proxima, Bellardi ; P. quadrilineata, Macq., is very 

 probably the same species. 



I have a series of specimens of a Pachyrrhina from Northern Sonora (Morrison), which 

 agree with the characters of P. ferruginea, but have the basal joint of the flagellum 

 reddish-yellow (sometimes also the second joint) ; the following joints are not altogether 

 black or brown, but reddish-brown, with the base only black. Such specimens are in 

 a dangerous proximity to P. suturalis, Loew, Cent. iv. 37 (Georgia) ; and if the latter 

 is a really good species, a closer definition than that of Loew will be required in order 

 to distinguish it from P. ferruginea. There are passages between specimens with a 

 decidedly black flagellum, and such where the basis of the joints only is decidedly 

 black ; also between specimens with distinct blackish spots on the abdominal segments, 

 and such where these spots are almost obsolete, or absolutely wanting. 



The other Mexican Tipulidse hitherto described (there are none from other parts of 

 Central America) are the following: — 



Geranomyia mexicana, Bellardi, Saggio &c. App. p. 4 (Aporosa). 

 Trimiera anomala, O. Sack. Monogr. N. Am. Dipt. iv. p. 167, t. 2. f. 1 ; 

 id. Catal. Dipt. N. Am. 1878, p. 29. 



