330 Mr. G. A. K. Marshall on 



specimens of Acrasas when they can get other butterflies. 

 Mr. Gordon writes of two Acra3as captured Jan. 13, 1902, 

 at Old Calabar : " So distasteful do these butterflies seem 

 to be that even the ants will not eat them. These speci- 

 mens are the only survivors of a set of about twenty. The 

 ants got in and ate all the rest, leaving these, as you see, 

 untouched." It is interesting to note that the species 

 were very different, being Acr/va admatha and A. ncohulc. 

 The specimens are in the Hope Department, Oxford. 



B, Prcdaccous Gohopt&ra. 



A great deal of work remains to be done with the 

 predaceous Coleoptera. So far as I am aware Professor F. 

 Plateau is the only naturalist who has made any important 

 use of them, but there is reason to infer from his experi- 

 ments that they too are important enemies to aposematic in- 

 sects. One section of his paper (Mem. de la Soc. Zool. de 

 France, tome vii, p. 875, § 9) is devoted to experiments in 

 which ^Z)?Ya;as larva? were offered to Carahusmirat'US,Dytis- 

 cvs marginatus [marr/inalis], and I), dimidiatus. Two of the 

 Carahi in confinement were starved for about eleven hours, 

 and then given one full-grown and two smaller larvre of 

 Abraxas. One beetle fed upon the large larva continuously 

 for about an hour, only leaving the thoracic region. The 

 other Carabus, of which one antenna was mutilated, after 

 half-an-hour attacked one of the smaller caterpillars and 

 then abandoned it. When the observer returned after a few 

 hours both the smaller larvae were partially eaten. Twelve 

 hours later the beetles were perfectly well. The experi- 

 ment was renewed with two fresh Carahi starved for 

 eighteen hours. The beetles began to devour the larger 

 of two larvae given to them, and even fought over it : in 

 an hour only the torn and empty skin remained. By the 

 next morning the second larva had been devoured, and 

 the beetles were quite healthy. Three imagines of Abraxas 

 were then offered to two freshly-caught Carahi. After 

 three hours one moth was nearly devoured, after about six 

 hours the second, and by the following morning the third. 

 There only remained some fragments of the wings. The 

 beetles were as active as ever. Several larvae were then 

 thrown into an aquarium containing the two above- 

 mentioned species of Dytiscus. The latter at once at- 

 tacked them, fighting over tlieir prey, which seemed to 

 be entirely consumed. 



