140 THE CHICAGO ACADEMY OF SCIENCES. 



at their tips, and the inferior very short; animal generally ter- 

 restrial. 



Monotremata. 



Common or contiguous external male and female orifice 

 (Binney). 



Sigmurethra. 



Ureter abruptly reflexed from the apex of the kidney, 

 passing to the posterior end of the lung-cavity, where an open 

 groove or closed tube continues across to the last fold of the 

 intestine, which it follows forward to the mantle-edge (Pilsbry). 



Superfamily Holopoda. 



Animal without pedal grooves; jaw always present, dis- 

 inct; none of the teeth of the aculeate type (Pilsbry). 



FAMILY HELICIDM. 



"Foot-edges without pedal grooves; no tail gland. Mar- 

 ginal teeth with wide, short, squarish basal-plates and one or 

 several cusps, the outer cusp never elevated on middle cusp. 

 Shell usually with expanded or reflexed lip."* 



Subfamily Polygyrinae. 



"Genitalia simple; vas deferens inserted directly on the 

 well-developed, long penis, which has no epiphallus or flagel- 

 lum; no dart sack or mucus glands; no diverticulum on sper- 

 matheca duct; eggs small and numerous. Jaw solid, ribbed or 

 smooth; marginal teeth with more than one cusp. Shell with 

 lip thickened within, expanded or reflexed, the embryonic 

 whorls not distinctly differentiated.'^ 



GENUS POLYQYRA (Say) Pilsbry. 



Polygyra SAY, Nich. Encycl., 3d Am. ed., Vol. IV, p. 7, 1818. 

 Stenotrema RAFINESQUE, Amer. Mon. Mag. and Crit. Rev., Vol. IV, 



p. 107, 1818. (Stenostoma.) 

 Triodopsis RAFINESQUE, 1. c., p. 107, 1818. 

 Mesodon RAFINESQUE Enumeration, etc., p. 3, 1831. 

 Neohelix V. IHERING, 1892. 

 Polygyra PILSBRY, Proc. Phil. Acad., 1889, p. 193; Guide to Study of 



Helices, p. 68, 1894. 



*Pilsbry, Guide to Study of Helicis, p. XXVIII, XXXII, XXXIII, etc. 

 fPilsbry, Guide to Helices, p. XXXII. 



