1910.] NATURAL SCIENCES OF PHILADELPHIA. 145 



Explanation of Plates I-XIV. 



Figures 35 and 36 B were drawn by Helen Winchester; the other figures were 

 drawn or photographed by H. A. Pilsbry. 



Plate I — Figs. 1,2, 3 — Sonorella bicipitis n. 3p. Types from Station 1, Buckeye 



Canyon, No. 94,328 A. N. S. P. 

 Figs. 4, 5— S. bicipitis. Nine-mile Water Hole. Nos. 94,324 and 89,908 A. 



N. S. P. 

 Figs. 6, 7, 8, 9 — Sonorella optata n. sp. Types from head of Big Emigrant 



Canyon. No. 94,319 A. N. S. P. 

 Fig. 10 — S. optata — Cleft in summit between forks of Big Emigrant Canyon. 



No. 94,321 A. N. S. P. 

 Figs: 11, 12, 18, 19 — S. optata. West side of Big Emigrant Mountain. 



No. 94,320 A. N. S. P. 

 Figs. 13, 14, 15, 16 — Sonorella bowiensis Pils. Topotypes, from Quartzite 



Peak, near Fort Bowie. No. 94,327 A. N. S. P. 

 Fig. 17 — S. optata, small form. Head of Big Emigrant Canyon. No. 99,789 



A. N. S. P. 



Plate II — Figs. 1, 2, 3 — Sonorella virilis Pils. Cave Creek, Station 11 (topo- 

 types of var. circumstriata) . No. 94,332 A. N. S. P. 



Figs. 4, 5 — S. virilis. Two miles up the south fork of Cave Creek. No. 

 94,335 A. N. S. P. 



Fig. 6 — S. virilis. Spring Branch near Rucker Camp, head of Rucker 

 Canyon. No. 97,563 A. N. S. P. 



Figs. 7, 8, 9 — Sonorella virilis leucura n. subsp. White Tail Canyon, Station 

 14. No. 99,682 A. N. S. P. 



Figs. 10, 11 — Sonorella micra n. sp. Station 10, White Tail Canyon. No. 

 94,334 A. N. S. P. 



Fig. 12—5. micra. Station 17, White Tail Canyon. No. 94,330 A. N. S. P. 



Figs. 13-18 — Sonorella binneyi n. sp. Horseshoe Canyon. 



Plate III— Fig. 1 — Sonorella bicipitis Pils and Ferr. Genitalia of specimen 

 from Buckeye Canyon. Station 3. X 3. No. 94,326. 



Fig. 2 — S. bicipitis. Genitalia of specimen from Nine-mile Water Hole. 

 No. 94,324. X 3. 



Fig. 3 — Side of the head of same specimen. 



Fig. 4 — S. bicipitis. Penis opened to show the papilla. Buckeye Canyon, 

 Station 4. No. 94,325. 



Fig. 5 — Sonorella binneyi Pils and Ferr. Genitalia of No. 97,414. Horse- 

 shoe Canyon. 



Fig. 6 — S. bicipitis. Sole of specimen from Nine-mile Water Hole. No. 

 94,324. 



Fig. 7 — S. bicipitis. Genitalia of specimen from Buckeye Canyon, Station 

 1. X 3. No. 94,328 (type lot). 



Plate IV — Fig. 1 — Sonorella optata Pils and Ferr. Genitalia of No. 94,322. 



Big Emigrant Mountain, X 3, with details of penis, papilla and the 



vestigeal flagellum (/?.). 

 Fig. 2—S. optata. West Side of Big Emigrant Canyon. No. 94,320. X 4. 

 Fig. 3 — S. optata. Big Emigrant Canyon, Station 1. No. 94,319. X 4. 

 Fig. 4— S. optata. Cleft in Big Emigrant Canyon. No. 94,321. X 4. 

 Fig. 5 — S. optata. Genitilia of young snail. No. 94,323. X 14. Outline 



of penis papilla shown by broken line. 

 Fig. 6 — Sonorella bowiensis Pils. Genitalia of a topotype. X 3. No. 



94,327. 

 Fig. 7 — <S. optata. Genitalia of a nearly mature snail. No. 94,323. X 4. 



Cross J. Mountain. 



Plate V — Fig. 1 — Sonorella micra Pils and Ferr. Genitalia. X 4. No. 

 94,334. From Station 10, "White Tail Canyon. The penis is extended, 

 its papilla projecting. 

 10 



