NOTES ON ORTHOPTERA IN THE SIAMESE MALAY STATES. 76 



amongst the guests of the genus Fciton. There is, of course, no 

 similarity of colouring, or at any rate only a chance resemblance, be- 

 tAveen these guests and their nearly blind hosts. The Avander-ants of 

 the genus Eciton have only simple ocelli, instead of compound eyes, 

 the former being more imperfect organs of sight than the latter. The 

 size and shape of these ocelli, however, differ in the different species. 

 They are very small and flat in Eciton i^raedator and E. coecum, and, 

 in consequence, their mimicking guests, Ecitonilla, EcitomdeH, and 

 Mimeciton, possess no similarity of colouring. The smallest worker- 

 ants of Eciton for eli have got comparatively larger and more arched 

 ocelli than the two other species. On this account I am still in doubt 

 whether there exists any true similarity of colouring between these 

 little black workers and their guests. These guests have certainly no 

 similarity of colouring with the big yellow warrior-ants. The question 

 of colouring is quite a secondary one, as the structure, hair-growths, 

 and shape of the body, calculated to deceive the sense of touch, are so 

 apparent. The case is quite different, however, with Eciton ccdiformcum 

 of North America. I was not a little astonished to see in a guest sent 

 me by Father Jerome Schmitt, O.S.B., which he had discovered with 

 this ant in North California, that the rust-red colour corresponded per- 

 fectly with that of its host. When I looked, however, at the eyes of the 

 latter through a lens the enigma was solved. They were comparatively 

 well-developed, arched, and twice as big as those of the same sized 

 workers of Eciton pracdator. It is, therefore, apparent that Eciton 

 cnliforniciun is able to see the colour of its guest, and so this element 

 has been changed also by the aid of mimicry. 



{To he continued.) 



Notes on Orthoptera in the Siamese Malay States. 



By N. ANNANDALE, B.A. 



The following are some general notes on the habits of the 

 Orthoptera made last year during the months of April to September, while 

 I was a member of an expedition sent out to Lower Siam under the 

 auspices of the Cambridge University and the leadership of Mr. W. 

 Skeat, of Perak, and with the kindly and most generous aid of the 

 Siamese Government. I hope soon to publish a more detailed account 

 of some of the insects mentioned, more particularly of the flower-like 

 Mantids and of certain of the Locustids. 



Earwigs are rare in those parts. A few species may be caught 

 round the lamp on some evenings ; on others, apparently identical as 

 regards temperature and weather generally, hardly an insect of any 

 kind is attracted by the flame. In the plains these fertile nights are 

 commoner than they are among the hills or in the midst of thick 

 jungle. A few earwigs, mostly immature forms, may also be found 

 under the bark of dead trees or in rotten timber. Sometimes a dug- 

 out canoe on the river is infested by them. In one cavern of the Jalor 

 caves, Chelisocheii morio, Fabr., abounded among the bats' dung on the 

 ground; and might be taken by laying a dry object, such as a camera- 

 case, in the middle of the cavern. Numbers both of adults and of 

 larvtB would soon crawl upon it, if it were left in the dark for a few 

 minutes. The cave specimens of this common species most probably 

 sought the outside world in the evening, as they were only found in a 



