222 



the normal form. There are other specimens showing a similar variation 

 and several are normal. The frontal aperture varies from subcircular to 

 a mere slit. 



The form of the spire varies from a fairly -well-cleveloped spiral cone 

 with flaring base and acute apex to a form approximating a disli Avith 

 very obtuse apex. The most dislc-like form observed belongs to a shell 

 less ventricose than the average and the spire is turned from the normal 

 position. The number of whorls in the spires seems to vary slightly, 

 though the material at hand does not admit of certain determination m 

 this respect. Unfortunately the crural attachments of the spires are not 

 shown in any of the specimens. However they must have been somewhat 

 modified to accommodate the twisted position of the spires, unless, in 

 the specimens examined, the spires which are abnormal had broken loose 

 in the shell prior to fossilization, Avhich I believe is improbable. 



The above variations, except in the case cited, do not seem to accom- 

 pany any particular form of shell. There is nothing visible in the spec- 

 imens to show the cause of their a1)normality. 



It is dangerous to generalize much on the observations based on a sin- 

 gle species. All that I suggest is that the foregoing seems to indicate 

 that in those spire-bearing brachiopods, particularly the Athyridae. where 

 the form of the shell does not govern the form and position of the spire, 

 i. e., those which approach a spherical form, the spiralia may be subject to 

 a considerable variation both as to the form of the spire and its position. 



Topography and Geography of Bean Blossom A' alley, Monroe 



County, Indiana. 

 V. r. Marsters. 

 In Monroe County. Indiana, and others lying to the southwest (Owen. 

 Greene, Martin. Dubois. Pike and Gibson) occur a number of preglacial 

 river valleys the present topography and content of which unmistakably 

 suggest the existence of a temporary period of laking. Inasmuch as the 

 attenuated edge of the Illinoian till plain passes diagonally through the 

 above counties and crosses the mouths of many of the southern tributaries 

 to the west branch of White River, which present evidence of arrested 

 drainage near the limit of the till plain, it seems probable that the laking 

 was consequently connected with the glaciation of the immediate region. 



