142 THE CHICAGO ACADEMY OF SCIENCES. 
For jaw and radula see the various species described.t 
Distribution:- North America (exclusive of some parts of 
the southwestern U. S.), Cuba, Bahamas and Bermuda.” ( Pils- 
bry.) 
Fie. 15. 
Genitalia of PoLtyGyra. (P. ANDREwSI, after Binney, Bull. Mus. 
Comp. Zool., Vol. XI, No. 8, pl. iii, Fig. E.) ag, albuminiparous gland; e, 
duct from testicle; gb, genital bladder; 0, ovary; ov, oviduct; or, orifice; pr, 
prostate gland; ps, penis; r, retractor muscle; t, testicle; vd, vas deferens. 
KEY TO SPECIES OF POLYGYRA, 
A. Aperture without heavily developed teeth. 
a. Shell encircled by color lines. 
1. Perforate,.. .cce- ob anos peter ree pra eaeee ie FPR profunda 
% AImpertorates oi. 2 Ues bees che Wa dle eee Lissette multilineata 
b. Shell plain horn-colored. 
*Shell large. 
1. Perforate, a small denticle on the parietal wall........ thyroides 
2. Imperforate, globose, parietal wall toothed, aperture 
widely duntate s,..|, Soc ive. sae PUR sealed chide ine sym eames exoleta 
3. Imperforate, depressed globose, tooth generally lack- 
ing, aperture narrowly lunate............ Lease albolabris 
**Shell small, less than half size of (*). 
l. Perforate 3.35, 5> spy hie tba ree whe eee bait Gan aes Om clausa 
2. Imperforate ......... Vuutic x otis tp kieie obs ape ---...Dennsylvanica 
tFor a general consideration of the jaws and radule of pulmonate mullusks, see.an ex- 
cellent paper by W. G. Binney in Proc. Phil. Acad., 1875, pp. 140-243. 
