Figure 6. Male diakinesis arrays for species deriving from the extinct, 2n=32 polymorphic Em ancestor. A. S. torquatus (Mexico: Michoacan; 7 km E center of Morelia, 2000 m elev.); B. S. grammicus "S" (Mexico: Mexico; Cerro Potrero contact zone [see Hall and Selander, 1973], 7.5 km W, 2 km S Rio Prio, 3350 m elev.); C. S. clarki (Mexico: Sinaloa; 6 km NNW Mazatlan) ; D. S. melanorhinus (same individual used in Fig. 5); E. S. m. megalepidurus (same locality as Fig. 5); F. S_. asper (same individual used in Fig. 4 and Fig. 5). Note the sex chromosome heteromorphism of all species. Also note the heteromorphic pairing of the chromosomes in the 9th bivalent of melanorhinus (column D) due to heterozygosity for the Em chromosome. Chiasma positions in the sex chromosomal bivalents or trivalents are indicated by small bars. The thick bar between pairs 2 and 3 in the cental columns represents 10 µm.