Download high resolution image here.

This subject came to a mercury vapor lamp set-up at 33°22'01.3N 108°04'23.4W, 6846 ft elevation, Wall Lake 7.5' quadrangle, about 1.5 miles north of Wall Lake near State Route 61 (Forest Road 150), Gila National Forest, Catron Co., NM. Many other images from this event are posted. I collected representative specimens of most, and can follow up with high resolution images of selected ones if needed. Size is determined from the sheet it's on having 80 by 100 threads per inch.

Followup:
I collected this specimen, and have linked high resolution images sufficient to confirm it as M. atropurpurea, based on the key of Cobos 1986 (1) and the original description of Say 1823 (2). The high resolution ventral view shows one of the pair of infrared receptors that members of this genus use to identify forest fires (3)(4).