MOLLUSCA OF MICHIGAN— WALKER. 



489 



''ig. 73. Dentition of A. agrestis. (Binney.) 



KEY TO THE SPECIES OF AGRIOLIMAX. 



I. Upper surface of body covered with smooth, flat tubercles separated 

 by shallow furrows darker than general body color; respiratory foramen sur- 

 rounded by a whiteish border; mucus milky white agrestis. 



II. Smaller; tubercles on body more prominent, not flattened, interven- 

 ing furrows of same color as general surface. Xo border around respiratory 

 orifice; mucus thin, colorless campestris. 



AGRIOLIMAX AGRESTIS (LiniiEeus). 



Body, when in motion, cylindrical, 

 elongated,«terminating acutely, tail short- 

 ly carinated; foot very narrow; upper 

 Fig. 74. -4. agrestis. (Binney.) surface rugose, rugsB Separated by darker 



colored, anastomosing lines; mantle large, ovate-oblong, rounded at both ex- 

 tremities, concentrically rugose; eye-peduncles elongated, cylindrical, ^Aith 

 small ocular bulbs; lower tentacles immediately under them, very short; 

 respiratory foramen posterior, large, surrounded T\Tth a whitish border; 

 color varying from whitish through every shade of cinereous and gray to 

 black, and through various shades of yellowish or amber-color to brownish, 

 unicolored or irregularly maculated with small black points; sole salloAv- 

 ^vhite; mucus milky. 

 Length 25-50 mm. 



Limax agrestis, Linnaeus. Svst. Nat. (x), I., 652, (1758). 

 . W. G. Binney, Man. Am. Land Shells, 453, fig. 498, (1885). 



A European species locally introduced. It has been found at Lansing, 

 Olivet and Lime Island in the St. Mary's river, and is reported from Ann 

 Arbor. Larger than our native species, A. campestris and differs externally 

 in the white ring around the respiratory orifice and the darker colored lines, 

 w^hich separate the rugae on the upper surface of the body and the milk^'-white 

 mucus which it exudes when touched. Anatomically the two forms are 

 easily separated. 



AGRIOLIMAX CAHPESTRIS (Say). 



Color usually various shades of amber or gray, without 



spots or markings, sometimes blackish; head and eye pe- 



^^ duncles smoky; body cylindrical, elongated, terminating 



A. campastris. in a very short carina at its posterior extremity; mantle 



■(Biniiey.) ' oval, fleshy, but little prominent, with fine concentric 



lines; back covered with prominent, elongated tubercles, intervening fur- 



row^s of same color as general surface; foot narrow, whitish; respiratory 



foramen on the posterior dextral margin of the mantle; mucus thin, watery. 



Leno;th 25 mm. 



Fig. 



