1902.] SPIDERS FROM BORNEO AND SIKGArORE. 267 



cephalothorax and a slender abdominal peduncle, so that the 

 triple division of the insect-body is well imitated. The abdominal 

 peduncle appears to bear a small scale and the abdomen is 

 elongated ; the elbowed antennte of an ant are mimicked by the 

 anterior pair of legs of the spider. I have not been informed 

 whether this species, like the preceding, lives in company with 

 its models. 



YIII. CONVERGENT GROUPS. 



There are certain combinations of colours in distasteful or 

 otherwise specially protected insects which may be considered as 

 warning : such are, black with yellow bands, black Avith one broad 

 red band, black with white tips to the wings, yellow or red with 

 black spots, red elytiu or wings more or less broadly tipped with 

 black ; and we find insects, belonging to the most diverse orders, 

 with one or other of these combinations of colours converging to 

 a central form, a typical distasteful insect. Some of these con- 

 verging forms may be non-immune and pseudaposematic (examples 

 of Batesian mimicry) ; others may be distasteful themselves and 

 synaposematic (examples of Miillerian mimicry). For example, 

 all the Lycidse are strongly distasteful, as I have proved by 

 repeated experiments \ and large numbers of them show the same 

 type of coloration, the anterior third or two-thirds of the elytra 

 being red, the posterior two-thirds or third black, whilst the head 

 and thorax are black or red. Resembling the members of this 

 group are ten species of Longicorns, belonging to four subfamilies, 

 one Olerid, two Hispids, two Elaters, one Rhipidocerid, one 

 Eucnemid, or seventeen Coleoptera in all, one moth and several 

 Hemiptera. The Lycidse, then, may be considered as distasteful 

 insects which are characterized by a definite type of warning 

 coloration, whilst the coloration of the insects which resemble them 

 so closely can hardly be looked on as essentially typical of the 

 groups to which the insects belong. The conspicuoiis Lycid, 

 Lycostomus gestroi $ , is mimicked by three Longicorns — Erythrus 

 apicidcotus var., £J. rottmdicoUis and sterncdis, and by Uiorycephahos 

 lundi, by a moth, Phatida limbata, by at least four bugs, of which 

 Ectatops ruhiaceus and Serinetha ahdominalis alone have been 

 identified. 



The arrangement of colours in the Lycid MetriorrhynchxiS 

 liirscM., in the Longicorns EpliAes dilaticornis and Erythrus biapi- 

 catus, in the Hispid Gonopliora xocdlacei var., and in a Olerid of 

 the genus Tenertis [T. sidcipennis (Gahan)) is almost identical. 

 CcdochromiiiS dispar is mimicked by the Longicorns Pyres^es eximitis 

 and P. virgata, by a Rhipidocerid of the genus Ennomaies, and by 

 an unidentified Encnemid. The Lycids Ditoneces sp. near fusci- 

 cornis and Taj^kes hrevicoUis, the Lamiid Longicorn Xyaste torrida, 



1 A strong vitality is correlated with this distastefulncss ; I have seen a Lycid 

 heetle walk away apparently uninjured after it had hcen well pecked hy two or three 

 fowls. The distasteful Eudomychidw are also difficult to kill {cf. also vitality of 

 Danaiiice, Acrmn(e, and Heliconinm noted by various authors;. 



