70 Forty-first Report on the State Museum. 



their presence. It was recalled tliat th.ey had been observed the 

 preceding autumn in nvimbers sufficient to cause them to be swept 

 together and burned. 



In this instance, the invasion does not rank with the first recorded, 

 but it may develop an increase in following years. 



The Fly Submitted to Baron Osten Sacken. 

 As the fl}'- was apparently unknown to us, it was submitted to Baron 

 Osten Sacken, of Germany, for determination, and by him was referred 

 to the genus Chlorops, subgenus Ghloropisca. It was found to have 

 some points in common with G. copiosa of Schiner, previously men- 

 tioned, but was different from it. As the species belonging to this 

 subgenus vary greatly in color, even more than the true Chlorops, 

 and are therefore quite difficult to identify from description however 

 carefully made, I requested of Baron Osten Sacken that he would 

 describe the examples placed in his hands, for publication in the 

 present report. The task was no light one, as may be seen from the 

 following description which he has most obligingly sent in compli- 

 ance with the request: 



Description of the Fly. 



Chloropisca peolifica n. si:>. [Osten Sacken.] 

 The breadth of the cheek under the eye is about equal to the distance 

 between the eye and the antenna; the front is but little projecting in the 

 profile, the face distinctly retreating. Front reddish-brown, shining, with 

 a narrow j^ellowish border along the edge of the occiput and the frontal 

 orbits ; a more or less distinct brown stripe in the middle of the front, 

 attenuate anteriorly and including the ocelli posteriorly; two shorter and 

 often less distinct lateral stripes ; frontal triangle^arge, nearly reaching 

 the anterior edge of the front, its anterior angle rather broad (not acute as 

 in some species of Chlorops), bounded on each side by shallow furrows (in 

 some specimens, however, they are deeper) ; near the occipital edge the 

 bottom of these furrows shows a couple of short, deeply-cut strife ; the sur- 

 face of the front is marked with scattered punctures (sometimes nearly 

 smooth ; in front of the ocelli, in most specimens, there is a shallow impres- 

 sion (coinciding with the intermediate brown frontal stripe). Face and 

 cheeks brownish-yellow. Occiput black or brown, yellow along the orbits. 

 Palpi reddish-yellow ; above them, a pair of black dots on the oral edge ; 

 when the proboscis is withdrawn these dots may be easily mistaken for 

 the end of the palpi. Antennae reddish-brown ; thii'd joint rounded, darker 

 brown on its distal half, sometimes altogether brown. Thorax brownish- 

 yellow, with the usual three black stripes and a shorter and narrower dark 

 streak above the supra-alar cavity ; the intermediate stripe is cutoff squarely 

 some distance before the scutellum, the lateral ones are elongate-wedge- 

 shaped, their pointed end nearly, but not quite, reaching the scutellum ; 

 a faint longitudinal groove along each side of the intermediate stripe ; 

 on the sternum a large black triangvilar spot between the front and mid- 



