1898.] NATURAL SCIENCES OF PHILADELPHIA. 175 



One large bristle, about twice as large as the largest of the posterior 

 surface, at the junction of the third and apical fourths, inserted 

 close to the edge of the posterior surface. 



Hind Leg. — Femur. — The usual rows present but of fewer and 

 smaller bristles than usual. Tibia. — No prominent bristles save 

 one very delicate flexo-lateral. 



Genus POLLENIA. 



I might consider the species to be here described as the type of a 

 new genus in deference to the views of Professor Brauer as I under- 

 stand them. He gives as one of the characters of Pollenia: " two 

 orbital bristles in the female." These specimens have from four to 

 six orbital bristles of large size inserted in a dorso-ventral line 

 roughly parallel to the insertions of the trans-frontal bristles and 

 laterad these large orbitalsand parallel to them another row of very 

 small bristles. I am sure that the number of large orbital bristles 

 may vary in individuals of the same species and, therefore, am per- 

 sonally of the opinion that their number is not always a character 

 of generic value, e. g., in our common species of Morellia the num- 

 ber of large orbital bristles varies from two to seven, frequently dif- 

 fering on the two sides of the same specimen. Such being the case, 

 it seems to me that I must include this species in Pollenia since it 

 presents all the characters of that genus except the one mentioned. 

 The woolly hair is present only on the caudal border of the meso- 

 pleura, caudad the row of bristles which protect the root of the 

 wing, a condition often met with in our common P. rudis if the 

 specimen is not fresh. The specimens look as if they had been wet. 

 Pollenia virido-cana nov. sp. 



Three females taken September 5, 1895. Length about 7.5 mm. ; 

 width of head about 2.2 mm., of front about 0.75, of frontal vitta 

 about 0.25 mm. Looking at the head directly from in front, the 

 height of the eye is 1.3 mm., of the bucca 0.4 mm. The highest 

 point of the vertex is a little higher (about 0.1 mm) than the high- 

 est point of the eye. The third antennal joint is twice as long as 

 the second. 



The general color of the fly is a dirty greenish-white or gray. On 

 close examination it is seen that the ground color of the thorax and 

 abdomen is a metallic green, but that this is more or less concealed 

 by a thick, whitish, hoary coating. In some lights there seem to 

 be two dorso-ceutral bands on the thorax which are free from this 



