1906.] NATURAL SCIENCES OF PHILADELPHIA. 175 



Fig. 14. — BulimuluH d. ozarkensis Pils. and Ferr. Seligman, Missouri. Xo. 



83,132 

 Fig. 15. — B. d. ozarkensis Pils. and Ferr. Rogers, Arkansas. Xo. 91,358. 

 Figs. 16, 17. — Bulimulus d. ragsdalei Pils. Types. Montague county, 



Texas. Xo. 58,380. 

 Figs. 18, 19, 20, 21, 22.— B. d. ragsdalei. Southwestern herd. West of 



Devil's river, Val Verde county, Texas. Xos. 91,356 and 84,638. 

 Figs. 23, 24. — B. d. ragsdalei Southwestern herd. Del Rio, Texas. Xos. 



87,486 and 91,355. 

 Fig. 25. — Bulimulus d. pasonis Pils. Tvpe. Xear El Paso, Texas. Xo. 



83,259. 

 Figs. 26, 27. — Bulimulus d. pecosensis Pils. and Ferr. Xear tlie Pecos river. 



Xos. 91,359 and 84,618. 



Plate VII. — Varieties of Bulimulus alternatus marioe (Alb.). 



Figs. 1-7.— Xear the High Bridge of the Pecos. Xo. 84,627, A. X. S. Phila. 



Figs. 4 and 5 represent young shells. 

 Fig. 8. — Xear the Rio Grande, east of the Pecos river. Xo. 84,625. 

 Figs 9, 10, 11.— Xear Rio San Filipe below Del Rio. Xo. 84,635. 

 Fig. 12. — Xear Rio San Filipe below Del Rio. An albino, taken alive. 

 Figs. 13, 14, 15, 16.— Corpus Christi, Texas. Xo. 60,136. 

 Figs. 17, 18, 19.— Hidalgo, Texas. Xo. 60,094. 

 Figs. 20-24.— Derby, Frio countv, Texas. Xo. 60,501. 

 Figs. 2.5-30.— Laredo, Webb county, Texas. Xo. 60,502. 



Plate VIII. — Figs. 1, 2, 3. — Helicodiscus eigenmanni Pils. San Marcos, Texas. 



Xo. 91,320. 

 Figs. 4, 6. — H. e. arizonensis Pils. and Ferr. Fort Bowie, Cochise county, 



Arizona. Xo. 87,077, A. X. S. Phila. 

 Fig. 5. — H. e. arizonensis. A more depressed specimen. Cave Creek 



Canyon, Chiricahua Mountains Xo. 87,076. A. S. X. Phila. 

 Figs. 7, 8, 9, 10. — Helicodiscus parallelus (Say). Philadelphia, Pa. Xo. 



78,272, A. X. S. Phila. 



Plate IX. — Figs. 1, 2, 3. — Planorbis filocincius Pils. and Ferr. Type. 

 Figs. 4, 5. — Planorbis carus Pils. and Ferr. Type. 

 Fig. 6. — Valvata micra nugax Pils. and Ferr. Type. 

 Figs. 7, 8, 9. — Valvata niicra Pils. and Ferr. Type. 

 Figs. 10, 11, 12, 13. — Cochliopa riograndensis Pils. and Ferr. Cotypes. 



