terminal segments of Aculeate Hymenoptera. 255 



distinct fovea in the substance of the segment, they 

 naturally remind one of the Cerci in the Orthoptera ; 

 but the latter occur on the 10th abdominal segment, 

 whereas these (reckoning the propodeum) occur on the 

 9th. The "Cerci" of the Tenthredinidce, however, occur 

 on the 9th segment, and to these the penicilli above 

 mentioned are, I think, clearly analogous. This 

 character appears to run through the entire section. 



FossoKES : MutillidcB. — Here, again, the " penicilli " 

 occur, at any rate in Mutilla and Myrmosa ; and as they 

 occur also in Myzine I think it very probable that this 

 last genus should be removed from the Scoliidce, and 

 placed here. The 8th ventral segment in both Metlioca 

 and Myzine is very plainly visible, and bears a peculiar 

 upturned process, very different from the apical arma- 

 ture of Scolia (see PL XIII., figs. 2, 2«, 3, 3a, Sh), &c. 

 Myzine also lacks the reniform shape of the eye 

 observable in the Scoliidce. 



Scoliidce. — In this family (see PI. XIII., figs. 4, 4 a, 4 h) 

 I can find no trace of appendages to the 8th segment 

 dorsally ; in most species it is produced and somewhat 

 rounded in the middle, but the ventral valve of the 8th 

 segment is conspicuously exposed, and armed generally 

 with three strong elongate prongs. The Scoliidce bear a 

 most striking resemblance in this armature, and also in 

 the genital armature, which has the stipites flattened 

 and dilated, to the Bemhecidce and Nyssonidce (see 

 PI. XIII., figs. 12, 12 a, 14, 14 a) ; and I cannot but think 

 that the position of these latter in the arrangement 

 should be transferred from where it now stands to an 

 earlier place in the section. 



TiphiidcB. — No apparent penicilli; 8th segment be- 

 neath with an upturned process (see PI. XIII., figs. 5, 5 a). 

 To my mind a very distinct family from the preceding, 

 the S having the genital armature laterally compressed, 

 and the cardo apparently produced above, and enclosing 

 the sagittas. 



Sapygidcs. — No apparent penicilli; 8th ventral seg- 

 ment simple ; exposed ventrally. 



PompiUdce. — Penicilli distinct ; it should therefore, 

 to my mind, follow the MutillidcB in arrangement ; 7tli 

 segment beneath very short, and visible only as a 

 shining spot at the base of the 8th ; 8th exposed 

 (sometimes mistaken for the 7tli), very variable in form, 



TRANS. ENT. SOC. LOND. 1884. PART II. (jULY.) S 



