82 [^P"i' 



dorsal lobes, oacli bifid witli a median bair, and one ventral, conical, with a 

 much shorter hair. 



R. cUspar (Perris, ibid. fig. So) apparently lacks both dorsal and lateral 

 tubercles (though this may be an omis.-ion by the artist) and each termiuiil 

 lobe is divided into three simple conical lobes, two dorsal, of which the external 

 is the larger, and one ventz'al, each bearing a seta. 



R. depressus (Perris, Ann. Soc. Ent. France, 1853, pi. xviii, fig. 90) agrees 

 with the last in having the terminal lobes divided each into three conical 

 setigerous branches, but here the internal dorsal is the larger ; the two seti- 

 gerous tubercles az-e present on the disc, and there are four pairs of lateral 

 tubercles. 



The larva described hj Eey {vide svpra) as that of JR. paralleJo- 

 collis has the two dorsal and one pair of lateral tubercles (all apparently 

 ivithout setae) and the terminal lohes are divided each into two, one 

 dorsal, strong, and curved upwards, and one ventral, short and somewhat 

 internally placed, provided with a seta (?i?. ferforaius'). 



The larvae of this genus are mostly found under hark, in the 

 galleries of various Seotytidae, on which they are predacious, though 

 they are said to feed also on the excrement of these larvae. They are 

 sonietimes found in fungi, but it is probable that they are feeding upon 

 the dipterous and coleopterous larvae by which these are often riddled, 

 and are not themselves fungivorous. 



It is interesting to note that one other species of the genus, 

 JR. perforatiis, shows a tendency to adopt habits similar to those of 

 a. parallelocoUis. In addition to records of its occurrence under bark 

 it has been found in the carcase of a dog, under a dead fowl, around an 

 old mutton bone (cooked) that had been buried eight da3^s, and under 

 dried cow-dung. In all these cases the presence of the JRhizophagus is 

 probably to be explained as a devourer of carrion-feeding larvae rather 

 than as itself a carrion-feeder. (N.B. — It is perhaps to this species that 

 Key's larva should be assigned.) 



Taking all these points into consideration, it seems only reasonable 

 to assume that the larvae of JR. parallelocoUis are predacious upon the 

 Phorid larvae in whose company they seem invariably to be found, and 

 that the supposed preference of the JRhizophagus larvae for the fat por- 

 tions of the corpse while the Phorids are more numerous upon the lean 

 portions may be due partly to accident and partly to the Phorids having 

 been somewhat thinned out in the vicinity of the JRhizophagus. The 

 presence of the JRhizophagus larvae in the hair, where also the Phorid 

 larvae and puparia were abundant (the Phorid larvae avoiding moist 

 situations when about to pupate), is a further indication that the 

 liliizopluigKS larvae were there merely to pi'ey upon the Phorids. 



