PLECIA.— BIBIO. 3 



the black middle line of the scutellum is not always present, and that the pale reddish 

 colour at the base of the antennae is variable in its extent. A male and two females. 



3. Plecia ruficollis. 



Plecia ruficollis, (Fabr.) Wiedem. Aussereur. zweifl. Ins. i. p. 72; Bellardi, Saggio &c. i. p. 15 \ 

 Hab. Noeth Ameeica, Florida l . — Mexico 1 . — South Ameeica 1 . 



The specimens thus named in Prof. Bellardi's collection are very like P. rostellata, 

 but the rostrum is short, the antennae altogether black, &c, in conformity with the 

 description ; the wings of the female are much narrower and smaller, and the branch of 

 the third vein much less oblique than in P. rostrata, Bell. 



4. Plecia bicolor. 



Plecia bicolor, Bellardi, Saggio &c. i. p. 16 \ 

 Hab. Mexico \ Presidio (Forrer). 



I refer to this species two female specimens from Presidio. The mesonotum is red, 

 the collar blackish, the rostrum long, &c. I have not compared them with the types. 



BIBIO. 



Bibio, Geoffroy, Hist. Nat. des Ins. ii. p. 571 (1762). 



1. Bibio ? 



Hab. Costa Eica, Irazu 6000 to 7000 feet (Rogers). 



A single female. It agrees with B. dubius, Bellardi, Saggio &c. p. 18 (Mexico), except 

 the words " stigmate fusco" the stigma being hardly darker. The types in Prof. 

 Bellardi's collection, four females, are difficult to examine under the dust and mould 

 that cover them ; three of the specimens have the wings darker than mine. 



2. Bibio ? 



Hab. Costa Rica, Irazu (Rogers). 



A single female. It agrees with B. swperfluus, Schiner, Reise d. Novara, Zool. iii. 

 Abth. i. p. 20 (Colombia, South America), except that the anterior cross-vein is shorter 

 than the handle of the cubital fork (about two thirds of it) ; the metanotum is but 

 little darker than the rest of the thorax. It is strange that Schiner should have 

 suggested its possible identity with B. thoracicus, Say, as Say distinctly says that " the 

 collar, scutel, and metathorax are black." 



3. Bibio ? 



Hab. Costa Rica, Irazu (Rogers). 



A single male. It is altogether black, but may nevertheless belong to the preceding 

 species. 



b2 



