OXYSTYLA, MEXICO, ETC. 123 



its genesis by bringing integrating forms to light ; and it may then 

 prove to be merely a form of some flammulate species, probably prin- 

 ceps orfentssaci, rather than an independent species. 



O. ZONIFERA (Strebel). PL 23, figs. 10, 11, 12, 13, 14. 



Shell ovate, moderately solid, smooth, with the usual microscopic 

 sculpture, finely plicate or puckered at the sutures. Whitish, closely 

 marked with numerous blackish-brown or bluish-brown streaks, some 

 in harmony with the growth-lin. s, others sinuous, narrower and gen- 

 erally forked at the upper fourth of the last whorl, wider in the middle, 

 and again narrower on the basal fourth ; penultimate and next earlier 

 whorls with broad patches, forked or narrow above, earliest 2^ whorls 

 yellowish-corneous with a minute blackish apical mark ; black-brown 

 varices narrow, widely separated, generally 2 to 4 on the whole shell, 

 1 to 3 on the last whorl. No trace of spiral bands on the last whorl, 

 but the antepenultimate or next earlier whorl has one submedian 

 band. Aperture ovate, streaked white and dark or mostly blue-white 

 within, quite oblique; peristome with a narrow black-brown edge; 

 parietal wall dark brown. 



Alt. GO, diam. 35.5, length of aperture 33 mill. 



Alt. 52.6, diam. 35, length of aperture 29.6 mill. 



Alt. 50.1, diam. 30.8, length of aperture 27.1 mill. 



Alt. 50, diam. 27, length of aperture 25.5 mill. 



Alt. 44, diam. 28, length of aperture 25 mill. 



Rancho del Platanillo near Iguala (Dona Estefania); Ckilpancingo 

 and Venta de Zopilote (H. H. Smith); Monte Pelegrino, north of Aca- 

 pulco (Berendt), all in the state of Guerrero. Colima, typical (Rolle). 

 Oaxaca (Ho'ge). 



Orthalicus zoniferus STREBEL, Beitr. Mex. Land- und Siisswasser- 

 Conch. v, p. 28, pi. 1, f. 7, 7b, pi. 3, f. 11 (shells), pi. 11, f. 7, 7, 

 8, 9 (anatomy) (1882). OrtaUchus zoniferus VON MATCTENS, Biol. 

 Centr. Amer. p. 180, 186, pi. 10, f. 12, 13 (exclusive of var. crossei). 



The main differential feature of this species is the distribution of 

 color on the body- whorl, the upper fourth and a tract around the 

 columella being paler and whiter, with narrower streaks than the 

 broad intervening belt, upon which the ground is often yellowish or 

 light brown, and the stripes wider and darker ; the surface being thus 

 divided between two pale polar zones and a broad darker equatorial 

 zone. The whorls of the spire are broadly blotched, as in 0. prin- 



