1916] Parker — Sarcophagidw of Neio England 133 



in Sarcqfahrtia are spread as in Ravinia and particularly resemble 

 those of R. latisetosa R. Parker. The parts of the penis are readily 

 homologized with those of Ravinia, especially R. cmnviunis. The 

 whole structure, however, is not so similar to that of this species of 

 Ravinia as are those of Wohlfahrtia opaca (Coquillett) and W. 

 chittendeni (Coquillett). 



The comparison given above is based on the following species: 

 Sarcofahrtia ravinia, Wohlfahrtia ojmca, W. chittendeni, Ravinia 

 communis, R. peniculata, R. latisetosa, R. qnadrisetosa (Coquillett), 

 R. hoematodes Meigen, R. xanthopyga (Van der Wulp) (?) and several 

 undescribed species of this genus. 



The resemblance of Sarcofahrtia to Sarcophaga is merely one of 

 general appearance. Some characters are similar to those of 

 Agria and Sarcophagula. 



The comparison of these genera seems worth while and illustrates 

 the fact previously suggested by the writer concerning generic 

 characters among such patently closely related genera as many 

 of those of this group (Parker, 1. c, p. 32). This suggestion may 

 be briefly summed up by saying that the diagnostic value of any 

 particular generic character is not to be found in that character 

 of itself, but is due to the particular set or group of other characters 

 with which it is associated. One might almost say of this group 

 that one character alone is not generic, and that it becomes so only 

 when associated with others that limit its application. 



It is doubtful if all possible characters have been included in 

 the generic description. Among those of doubtful rank may be 

 mentioned, palpi dull orange; uppermost pair of frontals in female 

 not noticeably, if at all, farther apart than preceding pairs (they 

 are farther apart in other genera discussed, except Agria). 



Sarcofahrtia ravinia sp. nov. (Fig. 1, page 137.) 

 (cf and 9 .) Second and third antennal segments pinkish orange 

 (usually, not habitually); palpi dull orange; hairs fringing calyp- 

 ters dark at bend, anterior face of posterior femur with two rows of 

 bristles only, a lower and an upper; posterior surface of middle 

 tibia of male with a single bristle on the middle line distal to the 

 center (two others are present in females, but are more proximal 

 and close to the median dorsal ridge) ; submesotibial bristle absent 

 in male. Forceps of male with prongs spread from near base {Ra- 



