Note 41 — APPENDIX.

Ants have been divided into three tribes, the two first of which, Formicineæ and Ponerineæ, are distinguished by the latter having a contraction in the abdomen not found in the former, and both are separated from the third tribe, Myrmicineæ by having but a single scale on the petiole, while in Myrmicineæ there are always two nodes or protuberances on the petiole. It is important to remember the difference between the first and the last named tribes, as we shall find that all the true harvesters belong to Myrmicineæ. I have not seen any of the representatives of the second tribe in the south.