12 Calvin Goodrich 



The fissure is 3 to 8 mm. in depth, always obHque. Of 20 specimens in 

 one lot, II have a wide fissure, in 9 it is narrow. Most of these latter in- 

 dividuals show signs of injury or deformation at the top of the whorl. 

 The girdle is cord-like, irregular, more or less conspicuous by reason of 

 differing in color from the body of the shell. 



Spillnianii is heavy, nodulous, though sometimes smooth, frequently 

 constricted, slightly plicate upon the early whorls. Fourteen shells in the 

 lot of 20 have stout, revolving folds, 5 have folds nearly obsolete and i is 

 smooth. Growth lines are fine to coarse, the scars of rest periods being 

 quite prominent. An adult with three remaining whorls measures 25 x 



13 1-2 mm. Color varies from sulphine-yellow to bufify-citrine. Bands 

 are four, all of the same width. This is the prevailing formula. Variations 

 are modifications of this formula. The aperture is wide, ovate, the sinus 

 at the base scarcely noticeable. The columella is white, thick, broadly 

 rounded and has a heavy callous at the top. The outer lip is slightly 

 sinuous, 



A young shell of five whorls is pyramidal, obscurely plicate, subangulate 

 at the base. The columella is small, undeveloped ; the fissure a mere curving 

 indentation. A full grown shell would have eight whorls probably if un- 

 eroded. 



The more nearly typical shells examined in the Alabama collections 

 were taken by Dr. Schowalter and the locality given is "Coosa River, Shelby 

 County, Ala." A smooth form, less rohust and with a shallow fissure cor- 

 responding with the types, was taken by Mr. Smith in Peckerwood Shoals. 

 No other localities are known. 



The type of zuhcatleyi, save in point of size, looks very much like spill- 

 manii in form, sculpture, bands and fissure. This seems to be the only 

 shell of the kind that was collected by Schowalter. Mr. Smith found two 

 small shells which I feel convinced are dwarfed spillmmiii, but curiously 

 they differ greatly from Lea's ztfheatleyi. 



In his formal description, Lea mentions Dr. Schowalter as the collector 

 from whom he received spillmanii. Latier, under "observations," he says, "I 

 have a number of specimens, chiefly young, from Dr. Spillman and a fine 

 suite of different ages from Dr. Schowalter." All these shells are in the 

 United States National Museum. Certain ones, with a label (i) pasted upon 

 them, I have ventured to assume to be the types. They correspond to the 

 Schowalter shells in the Alabama Museum collection. With them are two 

 specimens of G. pagoda Lea and a third Gyrotoma broken and indeterminate. 

 These probably are the sendings from Dr. Spillman. Three other lots 

 under the name of Spillmanii agree with the Schowalter mollusks and a 

 fifth consists again of pagoda. 



Group 0? Gyrotoma pagoda 



Conical to globose, smooth to striate, the young carinate and more or 

 less obscurely plicate ; fissure oblique to straight, not exceeding 10 mm. in 

 depth; girdle of varying size and color; aperture more frequently elliptical 

 than ovate ; sinus usually distinct ; bands, ordinarily four and equidistant. 



