MELANOSTOMA. 11 



I have not seen other specimens of this species, yet it seems probable that my deter- 

 mination is correct. At all events, the species seems to be the same as, or very closely 

 allied to, the one described by Schiner under tbe name of M. fenestratum, from South 

 America, the only discrepancy being in the pollen of the face, which is not " schwarz 

 punktirt," but has elongate, ripple-like markings. The black of the third, or third 

 and fourth abdominal segments is bisected, as in M. stegnum. The species forms, 

 with M. obscurum, Say, M. stegnum, Say, and M. jpunctulatum, v. d. Wulp, a natural 

 group, that might justly receive a generic name. 



3. Melanostoma buceplialus. 



Syrphus bucephalus, Wiedem. Aussereur. zweifl. Ins. ii. p. 126 \ 

 Melanostoma bucephalus, Willist. Trans. Am. Ent. Soc. xv. p. 264 \ 



Hab. Mexico, Amula 6000 feet, Xucumanatlan 7000 feet, Venta de Zopilote 2800 

 feet, Omilteme 8000 feet, all in Guerrero (H. H. Smith).—BRAZih \ Chapada 2 . 



Fourteen specimens. I have compared them with others from Chapada, Brazil, and 

 find no differences. M. euceratum, Bigot, seems to be an allied species. M. buce- 

 phalus, as Wiedemann remarks *, is allied to M. hyalinatum from Europe. 



4. Melanostoma mellinum. 



Musca mellina, Linn. Faun. Suee. p. 1821 \ 



Melanostoma mellinum, Willist. Synopsis N.-Am. Syrphidse, p. 49, t. 3. f. 9 2 % 



Syrphus melliturgus, Meigen, Syst. Beschr. iii. p. 329 3 ; Macq. Dipt. Exot. 4 e Suppl. p. 152 4 . 



Melanostoma (?) cruciata, Bigot, Ann. Soc. Ent. Fr. 1884, p. 81 s . 



Hab. Europe (auct.). — United States, New England, Kansas, and Pacific States 2 . — 

 Mexico 5 (H. H. Smith, Forrer). — South Ameeica 34 . 



I have carefully compared the numerous Mexican specimens with others from the 

 eastern United States, and find no difierences, except minor colorational ones. I have 

 little doubt of the synonymy of M. cruciatum, Bigot, notwithstanding the " thorax, 

 ecusson, presque noirs et luisants " ancl the small size. 



5. Melanostoma pruinosum. 



? Melanostoma (?) pruinosa, Bigot, Ann. Soc. Ent. Fr. 1884, p. 79 \ 



Ilab. United States, California K — Mexico, Sierra de las Aguas Escondidas 7000 

 feet (H. H. Smith). 



A single, female, specimen. In such species as this, Bigofs descriptions are usually 

 too vague for one to feel any degree of certainty in their determination. The Mexican 

 insect may be thus described : — 



* For fullcr synonymy, see Willist. loc. cit. 



