2S8 ]5rLLi:Tix 31, united states national museum. 



A)ttenna\ — Inserted close to.ijfthor in the lino l)c-t\veen the front and face, composed 

 of three joints, the third of which bears the: 



Arista. — A slender bristle situated upon the nppcr border of th(? third joint, micro- 

 scopically jointed near its base ; or: 



Style. — A thickened jointed arista (in Ceria and Pelccoccra) situated at or near the 

 lip of the third joint. 



Face. — The space between the base of the anteunit; and the oral margin, limited on 

 the sides by the eyes and checks. 



Facial tubercle. — A more or less ])ronoanced median convexity Ijelow the middle of 

 the face. 



Checks. — The space between the lower borders of the eyes and the oral margin, 

 merging into the face in front and limited by the occipital margin behind. 



Occiput. — The whole posterior surface of the head. 



Orbits. — A narrow indefinite space immediately bordering the eyes, and called ver- 

 tical, or superior; frontal and facial, or anterior; the orbits of the cheek, or inferior; 

 occipital, or posterior. 



Epistoma. — The oral margin of the face, and the region immediately adjacent. 



Oral or buccal cavity. — The mouth. 



Proboscis. — Mouth organs, near the base of which are inserted the small, one- 

 jointed ^Ja'iJi, and terminating in two flet^hy lips, the labellw. 



Mcntum. — The y)osterior oral margin. 



Dorsum. — The whole ujiper surface, limited by the dorso-pleural sutures laterally, 

 the scutellum posteriorly, and the neck anteriorly. 



Pleurce. — The lateral surfaces of the thorax. 



Pectus. — The inferior surface of the thorax between the legs. 



Scutellum. — A sub-hemispherical bod\'*behind, cut off by an impressed line fromtlie 

 dorsum of the thorax. 



Metaiiotum. — The posterior surface of the thorax between the scutellum and tlit^ 

 base of the abdomen. 



Humeri or shoulders. ^The anterior superior angles of the thorax. 



Post-alar callosities. — Rounded processes on the posterior lateral margins of the 

 dorsum. 



Transverse suture. — A transverse groove in front of tiie root of the wings, obsolete in 

 the middle of the dorsum. 



Dorso pleural suture. — The lateral suture, between the dorsum anfl the pleura^, ex- 

 tending from the humeri through the l>aso of the wings. 



Tcfjuhv. — Two membranous scales situated behiud the immediate base of the wing, 

 the upper overlapping the und<!r. 



Halteres or balancers. — An organ with a slender stem terminating in a rounded 

 knob, inserted in the raetathorax just in front of the lateral base of the abdomen. 



ABDOMEN. 



Incisures. — The sutures separating the segments. 



Venter.— The whole nnder surface of the abdomen. 



fTupopDfiium. — The male sexual organs and terminal segments of abdomen. 



Oviduct or ovipositor. — The terminal segments of the female abdomen. 



Coxos. — Basal segment attached to the thorax, terminating in a small ring-like seg- 

 ment, the trochanter. The next most elongate portion is the/eOT«r; then follows the 

 tibia; the joint between them is called the knee^ aTid expresses the innuediate contig- 

 uous portions of the femur and tibia. 



