CYLINDROTOMA. 299 



Mouches Dipt&res, 1803, Tab. XXYII), a circumstance which 

 has been entirely overlooked since, probably because this author 

 took the insect for a Pachyrrhina). Boie (Krojer's Tidskr. II, 

 p. 234; 1838) made a short mention, and Zeller (Isis, 1842, p. 

 808) gave the best description of the larva. 



Description of the species. 



1. C. americana 0. S. %. — Flava, capite flavo, thorace nigro- 

 fasciato, antennarurn articulis subcylindricis, elongatis ; cellulis pos- 

 terioribus quinque. 



Yellow, head yellow, thorax striped with black, antennae with subcylindri- 

 cal, elongated joints ; five posterior cells. Long. corp. 0.45. 



Syx. Cylindrotoma americana 0. Sacken, Proc. Entom. Soc. Phil. 18G5,p. 236. 



Head pale yellow, rounded and but little attenuated pos- 

 teriorly ; a pale brown spot on the vertex ; palpi brown ; the 

 antennae, if extended backwards, would reach the end of the 

 second abdominal segment ; two basal joints pale yellow, the first 

 not much longer than the second ; third joint yellow at the 

 extreme basis only, elongated, cylindrical; the following joints 

 brown, a little shorter than the third, elongated, subcylindrical, 

 slightly attenuated at the basis ; they are nearly of the same length 

 to the end of the antenna ; the flagellum is clothed on both sides 

 with a delicate and dense pubescence, among which some longer, 

 but also very delicate verticils are scattered. Thorax pale yel- 

 low, opaque above, with a black, opaque stripe in the middle, 

 reaching from the scutellum to the collare, and divided longitudi- 

 nally by a very narrow yellow line ; the lateral stripes are dark 

 brown, sometimes pale brown, abbreviated anteriorly and reach- 

 ing beyond the suture posteriorly ; a brown spot on the pleurae, 

 between the root of the wings and the collare and another brown 

 spot on each side of the sternum, between the first and second 

 pair of coxae ; halteres pale, dusky at tip ; feet yellow, tarsi 

 brown towards the tip. Abdomen brownish-yellow, darker aloug 

 the lateral margins ; its tip (in the male) is rather stout, club- 

 shaped. Wings hyaline, very slightly tinged with yellowish- 

 cinereous ; stigma short, pale ; the praefurca and the remaining 

 portion of the second vein are almost of equal leDgth ; the first 

 vein ends in the second at about the middie of the outer section 

 of the latter ; submarginal cell a little longer than the first pos- 



