1906.] _ NATURAL SCIENCES OF PHILADELPHIA. 175 
Fig. 14.—Bulimulus d. ozarkensis Pils. and Ferr. Seligman, Missouri. No. 
83,132 
Fig. 15.—B. d. ozarkensis Pils. and Ferr. Rogers, Arkansas. No. 91,358. 
Figs. 16, 17.—Bulimulus d. ragsdalei Pils. Types. Montague county, 
Texas. No. 58,380. 
Figs. 18, 19, 20, 21, 22.—B. d. ragsdalei. Southwestern herd. West of 
Devil’s river, Val Verde county, Texas. Nos. 91,356 and 84,638. 
Figs. 23, 24.—B. d. ragsdalei Southwestern herd. Del Rio, Texas. Nos. 
87,486 and 91,355. 
Fig. 25.—Bulimulus d. pasonis Pils. Type. Near El Paso, Texas. No. 
83,259. 
Figs. 26, 27—Bulimulus d. pecosensis Pils. and Ferr. Near the Pecos river. 
Nos. 91,359 and 84,618. 
Pirate VII.—Varieties of Bulimulus alternatus marie (Alb.). 
Figs. 1-7.—Near the High Bridge of the Pecos. No. 84,627, A. N.S. Phila. 
Figs. 4 and 5 represent young shells. 
Fig. 8.—Near the Rio Grande, east of the Pecos river. No. 84,625. 
Figs. 9, 10, 11.—Near Rio San Filipe below Del Rio. No. 84,635. 
Fig. 12—Near Rio San Filipe below Del Rio. An albino, taken alive. 
Figs. 13, 14, 15, 16—Corpus Christi, Texas. No. 60,136. 
Figs. 17, 18, 19.—Hidalgo, Texas. No. 60,094. 
Figs. 20-24.—Derby, Frio county, Texas. No. 60,501. 
Figs. 25-30.—Laredo, Webb county, Texas. No. 60,502. 
Puare VIII.—Figs. 1, 2, 3.—Helicodiscus eigenmanni Pils. San Marcos, Texas. 
No. 91,320. 
Figs. 4, 6.—H. e. arizonensis Pils. and Ferr. Fort Bowie, Cochise county, 
Arizona. No. 87,077, A. N.S. Phila. 
Fig. 5.—H. e. arizonensis. A more depressed specimen. Cave Creek 
Canyon, Chiricahua Mountains No. 87,076. A.5.N. Phila. 
Figs. 7, 8, 9, 10.—Helicodiscus parallelus (Say). Philadelphia, Pa. No. 
78,272, A. N.S. Phila, 
Prats IX.—Figs. 1, 2, 3.—Planorbis filocinctus 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 micra Pils. and Ferr. Type. 
Figs. 10, 11, 12, 18.—Cochliopa riograndensis Pils. and Ferr. Cotypes. 
