122 A MANUAL OF AMERICAN LAND SHELLS. 



from the aperture, and terminating in a line nearly marginal; edge 

 simple. 



This species varies in coloring. The form figured has its upper sur- 

 face dirty white, with oblique, longitudinal, dark blotches and a revolv- 

 ing dark band, below uniformly dark chestnut. Another form is like 

 this, excepting that the dirty white is replaced with light chestnut or 

 with dark chestnut. There are also forms where the dark chestnut 

 prevails over the whole shell, the band being sometimes obsolete, and 

 where the chestnut is sometimes replaced by uniform black. The 

 upper surface is, however, usually lighter than the lower; the band 

 when present is usually edged with white. The peristome is always 

 light-colored. The uniform dark form can hardly be distinguished 

 from A. infumata, sharing also the peculiar sculpturing of that species. 

 Indeed, there are grave reasons for suspecting that Jidelis and infumata 

 will prove one and the same species. 



Jaw : see above. 



The lingual membrane (Terr. Moll, V, Plate IX, Fig. C) has 48-1-45 

 teeth, with 15 laterals, the sixteenth tooth having a split inner cut- 

 ting point. The first marginal is shown as also an outer marginal. 



The genitalia of Jidelis and infumata are almost exactly similar. In 

 both the penis sac is extended into a decided flagellum. The vas def- 

 erens enters below the flagellate extension. The retractor muscle is 

 attached on the opposite side and still lower down. There is a well- 

 marked prepuce. Opposite the entrance of the penis, on the other 

 side of the vagina, which is here considerably swollen, is a sac-like 

 organ (Terr. Moll., V, Plate XV, Fig. E, pr. g), ending in a smoothly 

 rounded dart sac {d s), with a short dart within it. Just below this 

 dart sac opens the duct of another very variable organ {a g), cylindrical, 

 hollow, of a reticulated appearance, irregular in size, and bearing a 

 globular apex; it is much longer than the penis with its flagellum, 

 and stouter, as in Fig. E, or much less developed and without the 

 bulb, as in F. No dart was noticed within this organ. It is, no doubt, 

 a form of vaginal prostate, as described by Moquin-Tandon. The 

 genital bladder is globular. Its duct is long, free in the upper half 

 of its course. The oviduct, ovary, genital bladder, testicle, &c., of 

 infumata (Fig. F) are not figured by me. They are as in Jidelis (Fig. 

 E). This comparison of the genitalia strengthens the belief of th& 

 identity of the two forms. 



