This insect is entirely wingless. Head circular and flat, placed under the first segment. Antennæ composed of five equal articulations. Body rounded at top, forming an arch equal to one-fourth of a circle, and consisting of nineteen rings or scales, which lie very closely over one another, the hinder part of one exactly fitting the fore part of the next. Each of these scales, except some near the head, have four short feet fixed to them; the whole number of which is sixty. The general colour of the insect is whitish grey; the under part being lighter than the upper. Along the middle of the latter runs a darker shade, having a single spot of a wainscot colour placed on the middle of each scale. {97}PLATE XLIV. [Illustration] MYDAS CLAVATUS. Plate XLIV. fig. 1. ORDER: Diptera. SECTION: Notacantha, _Latr._ FAMILY: Mydasidæ, _Leach_. GENUS. MYDAS, _Fabr. Latr._ Midas, _Weidemann_. Musca, _Drury_, _De Geer_. MYDAS CLAVATUS. Niger, abdominis segmento secundo aurantiaco, alis nigris. (Long. Corp. 1 unc. 3 lin.) SYN. Musca clavata, _Drury, App. vol._ 2. (1773.) Bibio filata, _Fabr. Mant. Ins._ 2. 328. 1. (1787.) _Syst. Antl._ 60. 1. (Mydas f.) _Weidemann Aussereur. Zweifl. Ins._ 1. 240. 3. _tab._ 11. _fig._ 3. _Ditto in Nova Acta Nat. Curios. vol._ 5. _p._ 2. _pl._ 53. _fig._ 8. Nemotelus asiloides, _De Geer Mem. vol._ 6. _t._ 29. _f._ 6. HABITAT: New York, and other parts of North America. Head black. Antennæ nearly the length of the thorax, black, slender, and knobbed at their extremities. Thorax black and smooth. Wings coppery brown, very membranaceous, and not transparent. Abdomen black, and composed of eight segments, the second being of a deep yellow; which colour extends only to its sides, the under part being black. Legs entirely black; the hinder ones being furnished with a strong spine at the tips of the tibiæ, the middle ones having four small ones, and the fore ones none. Each of the ungues has two small yellow scales (puvilli) placed underneath. TABANUS PLUMBEUS. Plate XLIV. fig. 2. ORDER: Diptera. SECTION: Tabaniens, _Latr._ FAMILY: Tabanidæ, _Leach_. GENUS. TABANUS, _Linn, &c._ TABANUS PLUMBEUS. Obscurè coccinelleus, abdomine marginibus posticis pallidioribus, alis sublimpidis costâ fuscâ, antennis brunneo-rufis. (Long. Corp. 1 unc.) SYN. Tabanus plumbeus, _Drury, App. vol._ 2. Tabanus ruficornis, _Fabr. Syst. Ent._ 789. 8. _Syst. Antl._ 96. 14. _Weidemann Auss. Zw._ Ins. 1. 112. Tabanus Americanus, _Forster Novæ Sp. Insect. Cent._ 1. 100. Tabanus limbatus, _Pal. Beauvois Ins. d'Afr. & d'Amer. Dipt. t._ 1. _f._ 2. HABITAT: New York, Virginia, &c. North America.