10 BULLETIN 31, UNITED STATES NATIONAL MUSEUM. 



One specin>en, Isthmus of Tebuantepec (XatioDiil Museum, Profes- 

 eor Riley's collection). This species must resemble M. aurulentns, but 

 there are differences from Fabricius's brief description, as Wiedemann 

 pointed out, and especially from Macquart's, who it may be supposed 

 examined the type in Bosc's museum at Paris. It is also evidently 

 related to M. ineqimlis Loew, but differs especially in the pile of the 

 thorax. 



Microdon scitulus, n. sp. 



Habitat.— Flovidiil 



$ . Length, 6'"'". Bright metallic green and steel blue. Head hem- 

 ispherical. Front and face steel blue, narrow, the former lightly emar- 

 ginate on the sides, with short black pile, the least width less than the 

 distance from anterior ocellus to base of antennae; face but little project- 

 ing in ])rofile, thickly white pilose; antennae black; third joint a little 

 longer than the first, a little broader on its outer part ; arista slender. 

 Eyes bare. Dorsum of thorax with strong steel blue reflections, thinly 

 pilose. Scutellum subtriangular, spines moderately stout, approxi- 

 mate. Abdomen brilliant green, uniform, with fainter blue reflections, 

 finely i)unctulate, elongate oval, on the sides with oblique spots and 

 on the end white i)ubesceut. Femora, except the tip, metallic green, 

 tibiae yellow, tarsi more luteous. Wings nearly uniformly subinfus- 

 cated; outer cross- veins rectangular and straight. 



One specimen, Florida (National Museum, Professor Eiley's collec- 

 tion). This species might be identified as M. rufipes Macq. were it not 

 for the discrepancies in the pile of the eyes, face, and front. 



Microdon marmoratus. 



Microdon marmoratum Bigot, Ann. Soc. Eut. Fr., 1883, 3*J0. 



Habitat. — California (Bigot). 



$ . Long., 9"""'. Obscure fuscum, Jfavo pallido satis dense tomentosum. 

 Antcnnis fulviSj apice plus minus infuscatis; fronte et facie fuse is, laieri- 

 bus obscurd testaceis; abdomine utrinque, late, plus 7ninus fulvo tincto; 

 pedihus fulvis, femoribus basi, annulo tibiarum, tarsonim posticorum seg- 

 mento basilari, nigris; alls cinereis, apiee obscurioribus, venis fusco Urn- 

 batis. 9 . Simillima. Fronte et facie rujis. 



<J . D'un brun fonc6, assez dens^ment convert d'un duvet velout6 

 fauve clair, plus abondant sur le thorax ; antennes d'un fauve plus ou 

 moins fonc6, souveut brunatres vera leur extremity ; face et front bruns; 

 thorax rougeatre sur les cotes, 6cusson plus ou moins roussatre; cuil- 

 lerous et balanciers d'un testac6 pale ; abdomen souvent un peu rous- 

 satre sur les cdt^s ; pieds fauves, base des cuisses largement noire, un 

 anneau an milieu des tibias, et, base des tarses post(5rieurs, de meme 

 couleur ; ailes grises, l^gferement enfum<§es au bord externe et a Fex- 

 tremite, nervures largement bord6es de brunatre. $ . Semblable au 

 $ . Face et front rougeatres. Californie. — 4 3,39 . — Bigot, 1. c. 



$ . Dark brown, densely clothed with clear fawn-colored velvety 

 pile, more abundant on the thorax; antennae more or less dark fawn- 



