114 THE NAUTILUS, 



bridge at Arkadelphia; also Caddo River near County bridge 

 five miles North of Arkadelphia. 



Lymruea hxmiUis •modkcUa Say. Found in the environs of 

 Arkadelphia; in Mill Creek; rarely in the Ouachita River mar- 

 gins. Rare! 



Planorbis trivolvis Say. Ouachita River, Old River, and Big 

 Deceiper Lake, nine miles south of Arkadelphia. 



Phinorbis dilatatus Gould. Ouachita and Old Rivers. There 

 are possibly two forms in this lot. 



Planorfm samps(yai (Ancey). Clear Lake, two miles east of 

 Arkadelphia, and ponds south of Arkadelphia (young shells 

 only). This species seems to be exceedingly perishable. 



Ancylus kirklandi Walker. Caddo River (common) Clear 

 Lake. 



Ancylus walkeri Pilsbry and Ferriss. Ouachita River at Ark- 

 adelphia. Very rare. 



Ancylus sp.f Ouachita River near Arkadelphia. 



Physa anatina Lea. Mill Creek, ponds south of Arkadelphia, 

 and Big Deceiper Creek at Gum Springs, six miles south of 

 Arkadelphia. 



Physa sp.f Clear Lake east of Arkadelphia. 



Strobilops lahyrinthica (Say). Arkadelphia. Everywhere 

 common in suitable localities. 



Strobilops labyrinthica texcmana Pilsbry and Ferriss. Arkadel- 

 phia. Not uncommonly there is found what seems to be a 

 hybrid between this variety and the species proper. 



Strobilops virgo (Pils). Arkadelphia, but found also in the 

 bordering county of Grant. 



Pupoides marginatus (Say). Arkadelphia. 



Gastrocopta contractu (Say). Arkadelphia. 



Gastrocopta contractu climeana Van. Arkadelphia, very rare. 



Gastrocopta pentodon (Say). Arkadelphia. 



Gastrocopta tappaniana (C. B. Ads). Arkadelphia. Col- 

 lected also in adjacent counties north and east of Clark. 



Succinea avara Say. Environs of Arkadelphia, not common. 



Omphalina friabilis (W. G. Binn. ). Arkadelphia. Very 

 rare ! 



Vitrea indentata (Say). Arkadelphia ; Gurdon. 



