The Mantis-killing Tachytes wears a red scarf, like her kinswoman, Panzer's Tachytes. (The Mantis-hunting Tachytes was submitted to examination by M. J. Perez, who failed to recognize her. This species may well be new to our fauna. I confine myself to calling her the Mantis-killing Tachytes and leave to the specialists the task of adorning her with a Latin name, if it be really the fact that the Wasp is not yet catalogued. I will be brief in my delineation. To my thinking the best description is this: mantis-hunter. With this information it is impossible to mistake the insect, in my district of course. I may add that it is black, with the first two abdominal segments, the legs and the tarsi a rusty red. Clad in the same livery and much smaller than the female, the male is remarkable for his eyes, which are of a beautiful lemon-yellow when he is alive. The length is nearly half an inch for the female and a little more than half this for the male.--Author's Note.) I do not think that she is very widely distributed. I made her acquaintance in the Serignan woods, where she inhabits, or rather used to inhabit--for I fear that I have depopulated and even destroyed the community by my repeated excavations--where she used to inhabit one of those little mounds of sand which the wind heaps up against the rosemary clumps. Outside this small community, I never saw her again. Her history, rich in incident, will be given with all the detail which it deserves. I will confine myself for the moment to mentioning her rations, which consist of Mantis-larvae, those of the Praying Mantis predominating. (Cf. "The Life of the Grasshopper": chapters 6 to 9.--Translator's Note.) My lists record from three to sixteen heads for each cell. Once again we note a great inequality of rations, the reason for which we must try to discover. What shall I say of the Black Tachytes (T. nigra, VAN DER LIND) that I have not already said in telling the story of the Yellow-winged Sphex? ("The Hunting Wasps": chapters 4 to 6.--Translator's Note.) I have there described her contests with the Sphex, whose burrow she seems to me to have usurped; I show her dragging along the ruts in the roads a paralysed Cricket, seized by the hauling-ropes, his antennae; I speak of her hesitations, which lead me to suspect her for a homeless vagabond, and finally on her surrender of her game, with which she seems at once satisfied and embarrassed. Save for the dispute with the Sphex, an unique event in my records as observer, I have seen all the rest many a time, but never anything more. The Black Tachytes, though the most frequent of all in my neighbourhood, remains a riddle to me. I know nothing of her dwelling, her larvae, her cocoons, her family-arrangements. All that I can affirm, judging by the invariable nature of the prey which one sees her dragging along, is that she must feed her larvae on the same non-adult Cricket that the Yellow-winged Sphex chooses for hers.