218 A NATURALIST IN THE GREAT LAKES REGION 



is amber if empty, dark brown when the animal is in it. Cir- 

 cinaria concava is .5 inch or more in diameter, green horn-color 

 outside and red-brown within the aperture. 



The great slug, Philomycus carolinensis (Fig. 285), and the 

 smaller slugs, Agriolimax campestris (Fig. 288) and Pallifera 

 dorsalis, are found in similar situations. Not infrequently under 

 strips of bark one finds clusters of the eggs of slugs or snails like 



FIG. 289. The large millipede, Spirobolus marginatus 



heaps of small pearls. Philomycus is yellow white, spotted with 

 brown or black. The other two are ashy in color. Pallifera has 

 a dark line down the back and is less than an inch long. Agrioli- 

 max is larger with no line down the back. Under the bark of 

 logs in midstages of decay one finds also several centipedes and 

 millipedes. The big round Spirobolus marginatus (Fig. 289) 

 .5 inch in diameter and 5 or 6 inches long when full grown is 



FIG. 200 



FIG. 291 



FIG. 290,291: Fig. 290. Yellow-margined centipede, Fontaria corrugate, 

 Fig. 291. The red centipede, Geophilits rubens. 



fairly common. Another, Fontaria corrugate (Fig. 290), is flat- 

 tened somewhat and is brown in color with yellow margins. 

 Lysiopetalum lactarium, a centipede, discharges a milky fluid 

 when handled, while Geophilus rubens (Fig. 291) is a large reddish 

 fellow. Sow bugs and roaches are abundant here, too. In logs 

 that are in earlier stages of decay one finds numerous boring 

 beetles. The click beetles and their larvae, the wire worms, 



