70 PROCEEDINGS OF THE ACADEMY OF [Jan., 



lines is more or less uniform and, for convenience in describing the 

 extent and character of the pattern, we have referred to this as the 

 dorsal color, the ventral and lateral tones as the lateral color, and the 

 pale paired lines and their developments as the pale pattern. The 

 range of tone in all three of these principal components of the colora- 

 tion is very considerable, the extreme on one hand having the pattern 

 intense, the contrasts decided and the tones darker and richer, while 

 in the other extreme the pattern is dilute, the contrasts poor and the 

 tones paler and weaker. To facilitate reference to these extremes 

 we have termed them the intensive and recessive extremes. In the 

 recessive condition the pale pattern is frequently much restricted as 

 well as weakened, while the dorsal color is often but little, in part 

 only, or not at all different from the lateral color. 



Distribution. — Extending from north-central Texas (Dallas), 

 southern New Mexico (Dry Canyon and Mesilla Valley) and central 

 southern Arizona (Tumamoc Hill and Sycamore Canyon), south 

 to the upper Rio Balsas Valley in Guerrero, Mexico, on the west 

 reaching Tepic and on the east the vicinity of the coast at Corpus 

 Christi and Brownsville, Texas, and Tamos, Vera Cruz, Mexico. 

 Vertically the genus ranges up to at least 6500 feet (in the Davis 

 Mountains, Texas). It reaches its greatest diversity in southern 

 Texas and the northern and central parts of the Mexican tableland. 



History. — In 1878, Brunner^ erected the genus for two species then 

 described, viz., mexicana (from Mexico) and emarginata (from Texas). 

 In 1880, Bormans^ described a species from Schoa, Abyssinia, as 

 Dichopetala massaice, which has since been placed in the genus 

 Peropyrrhicia, which is exclusively African. Scudder, in 1900, 

 described^ a Dichopetala hrevicauda from California, which we now 

 know to be an Arethcea and not at all related to Dichopetala. In 

 1901, Rehn^ described a new form from Mexico as D. pidchra, basing 

 it on material which he had previously recorded as mexicana. Scud- 

 der, in 1902, in Scudder and Cockerell's list of New Mexican Orthop- 

 tera" described as new a species of the genus from New Mexico, 

 calling it Dichopetala hrevicauda, but as that name was preoccupied, 

 Morse, at Scudder's suggestion, renamed the species D. hrevihastata? 

 In 1907, Rehn described a species from Arizona as D. loBvis.^ 



2 Monogr. der Phancropt., p. 76. 



' Ann. Mus. Civ. Slor. Nat., Genova, XVI, p. 218, fig. 



■< Canad. Enlom., XXXII, p. 331. 



5 Enlom. News, XII, p. 207. ^ 



•"' Proc. Davenp. Acad. Sci., IX, p. 51. 



T Psyche, IX, p. 381. 



* Pitoc. Acad. Nat. Sci. PniLA., 1907, p. 50. 



