UIPTERA. 371 



almost not) turned up inferiorly. The antennae are inserted on the 

 top of the front, and sometimes even received in fossulae, but they 

 most commonly project, are straight and distant, and in several as 

 long as the head, or longer. In all the other Muscides they are 

 always shorter than the head. 



The Muscides of the fourth division, that of the Scatomyzides, as 

 well as those of the fifth, are distinguished from the species of the 

 sixth by the following characters: the head, viewed from above, is 

 never longer than it is broad, its form being nearly spherical or trian- 

 gular ; the posterior legs are never much longer than the body, nor 

 very slender, and the body, though sometimes narrow and elongated, 

 is not filiform. 



Here, the Scatomyzides are distinguished from the Muscides of the 

 following division, or the Dolichocera, by their antennae, of which 

 the third joint is evidently longer than the preceding one ; with the 

 exception of a single genus, Loxocera, they are always shorter than 

 the head. The anterior and superior extremity of this latter part of 

 the body rarely projects beyond the eyes, and when viewed from 

 beneath usually appears almost hemispherical, and rather wider than 

 it is long. 



Sometimes the posterior legs are large and distant, their thighs 

 are thick or compressed, and the joints of their tarsi dilated or 

 widened. The antennje are always very short, with the last joint 

 lenticular or nearly globular, and furnished with a simple seta. The 

 sides of the face are pilose and silky. 



Thyreophora, Lat., Meig. — Musca, Panz., 

 Where the antennae are received into a sub-frontal cavity, with a 

 lenticular, but not transverse, palette ; the head gradually inclines 

 from its summit to the mouth ; the posterior thighs are thick, and the 

 second and following joints of the tarsi are almost similar. 



All the terminal cells of the wings are closed by their posterior 

 edge. The palpi are much widened at the end in the manner of a 

 spatula. 



T. cynophila, Panz., Faun. Insect. Germ. XXXIV, 32. Deep 

 blue ; head reddish-yellow ; two black points on each wing ; 

 scutellum terminated by two spines. Found on dead dogs, and 

 always in autumn. According to an observation communicated 

 to me by one of our most learned and zealous entomologists, M. 

 Percheron, Jun., this Insect is sometimes phosphorescent, a pecu- 

 liarity that struck one of his friends who witnessed it in his 

 chamber at night, and induced him to capture it*. 



Sph^erocera, Lat. — Borborus, Meig. — Copromyza, Fall., 

 Where the antennae are salient, with the palette almost hemisphe- 

 rical and transversal ; the head is abruptly concave below the front 

 and turned up near the oral cavity, of which the superior extremity 

 is bordered ; the posterior thighs are compressed, and the two first 

 joints of their tarsi are evidently wider than the following ones. 

 The second cell of the posterior extremity of the wing — the last 



* Lat., Gener. Crust, et Insect., IV, 35S ; and Meigcn. 



