14 AMERICAN ENTOMOLOGY. 



tures ; maxillae not longer than the thorax, and with the antennae 

 and palpi black. 



Desc. Antennae black, basal joint pale testaceous ; eyes, max- 

 illae, palpi and tips of tarsi, black ; elytra irregularly punctured, 

 naked, polished. 



Obs. It inhabits the plains of Missouri, and was captured by 

 Mr. Thomas Nuttall, on a species of thistle ( Car dims ;) I have 

 since observed it in some plenty in the same locality. It seems 

 to be allied to the Zonitis pallida of Fabricius, judging by his 

 description of that insect. 



The smaller figure of the plate denotes the natural size, and 

 the figures beneath it exhibit magnified representations of some 

 of the oral organs, &c. 



Fig. 1. Antenna. 



2. Mandible. 



3. Tongue and labium supporting the labial palpi. 



4. Labial palpus. 



5. Maxilla with its palpus, verticillate with short hairs- 



XYLOTA. Plate VIII. 



Generic character. Antennae three-jointed, inserted on a frontal 

 elevation, nutant; third joint suborbicular, compressed, with a 

 naked seta placed behind the dorsal middle ; ocelli three ; pro- 

 boscis with fleshy lips ; hypostoma above impressed, near the 

 mouth a little elevated, retuse and sub tuber dilated ; posterior 

 thighs dilated, spinous beneath ; onychii two ; abdomen with five 

 segments ; wings incumbent, parallel. 



Obs. For this genus we are indebted to Meigen. Linne, Gme- 

 lin, Degeer, Schrank, and others, referred the species to Mtisca ; 

 Fabricius and Panzer to Syrphus and Milesia. In his Systema 

 Antliatonim Fabricius, with Latreille and Fallen, included them 

 in the genus Milesia ; and a few species were scattered in the 

 genera Merodon, Scseva, Eristalis, and Thereva, by several 

 authors. 



The species are found on flowers, and the larva is supposed 

 to inhabit decaying wood. 



Xylota quadrata. — Specific character. Blackish; ter- 

 gum with four dilated subequal ochraceous spots; posterior 

 thighs with a prominent angle near the tip. 



