The Bionomics of Sovth African Inscds. 510 



All were captured at Salisbury, in Nov. 1898, with the 

 exception of those specially noted as taken between Nov. 

 1898 and Jan. 1899. 



Other species are not included in the Plate for want of 

 space. Thus Piezia viar.'^Jialli has a single median white 

 spot, of which half is on one elytron and half on the other, 

 in place of the posterior, well-separated pair of spots on 

 P. scloud ; and there are other species, outlying members 

 of the group under discussion, in which tlie Mutilloid 

 appearance becomes less marked, while in Pohiliirma scmi- 

 mdii.rafa it fades away altogether, although this intensely 

 black beetle, with its white dorsal line anteriorly and white 

 patch posteriorly, seems to be very coi>spicuous. The 

 appearance of the group and the relation to the outlying 

 species suggest a strong and very complex Mlillerian 

 association. The larfje Carabidc'B of the gfenus Antliia 

 are either entirely black or possess a peculiar synapo- 

 sematic appearance, described on pp. 508-510, and figured 

 on Plate XVII, figs. 22 to 20. The smaller CaraUdfe, 

 depending upon a less development of the same defence 

 — the power of discharging a strong acid secretion — 

 have gained an appearance, due, like that common in 

 A)Uliia, to white markings on a black ground, but arranged 

 so as to suggest more or less strongly the likeness of a 

 MvtiUa. In a single species, as Mr. Marshall points out, 

 the resemblance is extraordinarily exact (Plate XVII, 

 fig. 11). This may be on account ef habits and a mode 

 of life which render the likeness especially beneficial. 

 The smallest Carcibidx, the Atractonota and Polyldrma 

 /enigma (Plate XVII, figs. 7-10), in shape resemble large 

 ants, and Mr. Marshall states above that the movements of 

 the former aid in producing tliis effect. On the other 

 hand, their white spots appear to be certainly Mutilloid or 

 perhaps rather to resemble the Mutilloid white spots of 

 the other unant-like Carahid^. Nothing is more char- 

 acteristic of a Mlillerian (synaposematic) group than the 

 complexity of likeness which is thus revealed, and yet in 

 the light of the great hypothesis which we owe to Fritz 

 Mllller it is not difficult to understand the general principles 

 which account for its existence. 



The Garahidm are a powerful, specially defended group, 

 and it is of advantage to be recognized as belonging to 

 the group, even though it is no doubt - of still greater 

 advantage to be mistaken, as may happen at a distance, 



TRANS. ENT. SOC. LOND. 1902. — PART III. (NOV.) 34 



