Roundy — Color Markings of Carboniferous Gastropods. 447 



furnished numerous examples clearly showing coloration. 

 One of these is the well-known Holopea jproutana, of which 

 33 specimens show this character. The other is a new species 

 which seems to belong to DeKoninck's genus Glyptobasis and 

 of this no less than 71 specimens retain color markings. The 

 collection which furnished this interesting material is from the 

 Spergen limestone at Stinesville, Indiana. 



Acknowledgments are due Dr. George H. Girty for his 

 assistance in the study of this material, and Dr. E. O. Hovey 

 of the American Museum of Natural History of New York 

 for the loan of Hall's type specimens of Holopea jproidana. 



Glyptobasis marshalli n. sp. 



Shell small, averaging about 7 mm in height and 3 - 5 mm in great- 

 est diameter and consisting of 6 to 7 whorls. Shape nearly 

 conical ; whorls usually with a slight angle just below the 

 periphery causing the base to be somewhat flattened ; sutures 

 distinct and slightly depressed. The side of the volution is 

 smooth but the base is covered with strong, regular revolving 

 striae, which become obsolete toward the periphery so that each 

 whorl conceals the strise on the base of the preceding one. 

 Height of last whorl slightly greater than height of spire. 



In a very few shells, 12 in 325 specimens, persistent striae 

 are shown which are visible on the sides of the whorls. In 

 these specimens, however, the strise on the sides are very 

 obscure and might pass unnoticed even with a strong hand 

 lens, while those on the base are very much stronger. 



The aperture is roughly rhomboidal without a callous. The 

 part forming the extension of the axial portion appears to be 

 slightly folded backward. There appears to be no umbilicus 

 when the shell is examined from the outside. A longitudinal 

 section, however, shows a narrow umbilicus extending to the 

 apex. 



In the Stinesville collection there are 265 specimens, of 

 which 71 retain distinct remains and 10 more show traces of 

 coloration. The body color of these shells is a brownish gray 

 while the ornamentation consists of darker yellowish-brown to 

 mahogany colored transverse stripes. Were growth lines 

 present the color bands would roughly correspond with them 

 in direction. In the umbilical region, however, they merge, 

 making the central part of the base dark-colored. 



Unlike the bands on Holojpea jproxitana these do not have 

 sharp boundaries although they are very distinct. Further- 

 more, on this species the stripes vary considerably in arrange- 

 ment. Their width is rather constant, about '13 mrn , but in 

 some specimens they are close together ; in others they are 



