288 Mr. Westwoop on Diopsis, 
Athericera (containing the Syrphide), of which “le Sucoir se compose de 
quatre pièces, et non de deux comme dans tous les autres Athericéres;” the 
two maxillz being clearly developed* and very acute, and the palpi longer 
than the labrum, compressed, and broader towards the apex than at the base. 
The aBDOMEN exhibits another peculiarity, all the specimens which I have 
examined having the four basal joints soldered together, without any distinct 
articulation, on the upper side of the abdomen: this is the case even in D. sig- 
nata and fasciata, in which the situation of the articulations is indicated by a 
black slender line. This structure is represented in Linneeus's original figure ; 
but Dalman, who drew the figures accompanying his memoir, has represented 
the articulations of the basal segments in all his species. 
DIOPSIS. Linn. et Auctt. 
Characteres Generis. 
Corpus parvum, elongatum, longitudine vix dimidium uncii equans. Caput 
parvum, suprà subtrigonum, facie anticá perpendiculari, subconicá, sub- 
tùs truncata, mutica, vel utrinque unispinosá, latere supero vel vertice 
in medio ocellifero, et utrinque in cornu longissimum cylindricum plüs mi- 
nüsve gracile subascendens, ad apicem oculiferum, et paulld ante apicem 
antenniferum divergens producto. Hsec cornua in medio vel pone medium 
seta unica alteraque ad apicem supra oculos armantur. Antenne minime, 
compresse, 3-articulate articulo 1mo minimo transverso, 2do majori 
cyathiformi, 3tio suborbiculato suprà feré ad apicem, setá (basi articu- 
latà, simplici longà. Os in cavitate capitis inferà retractile. Pro- 
boscis magna, membranacea, geniculata. Portio basalis magna, rotun- 
data, et pro receptione partium oris internarum concava (an labri vera 
pars analogica?). Labrum (dimidii labii longitudine) acuminatum, crus- 
taceum, et pro receptione linguæ subtüs carinatum. Lingua labro paullo 
brevior, gracilis, compressa. Maxillæ distinctze, linguá breviores, gra- 
ciles, acutissimee. Palpi labii feré longitudine, ad basin arcuati (articu- 
lati?), compressi, versus apicem dilatati, pilosi. Labium magnum, stipite 
* Since this account was written, Mr. Curtis has illustrated the genus Borborus in his “ British 
Entomology,” which he describes as possessing ‘‘ maxillae very small and linear." (Brit. Ent.469.) 
