G. TI. Girty — Growth Stages in Naticopsis altonensis. 339 



more, as indicated by a specimen in my collection. The 

 variety gigantea in a figure by Meek and Worthen is over 

 60" ,m long. 



The specimens furnishing these data were collected near 

 Garland, Henry County, Missouri. 



II. Notice of a Mississijypian gasteropod, retaining coloration.* 

 Plate I, figs. 9-11. 



The student of fossil shells has small chance to forget that 

 the material which he is studying has suffered a loss of char- 

 acters, and none of these is probably more early and more com- 

 pletely obliterated than that of coloration. Thus the paleon- 

 tologist is deprived of this important aid in discriminating and 

 identifying species. This is almost as true of the most recent 

 fossils as of the most ancient, yet even in the Paleozoic an 

 occasional specimen is found which retains traces more or less 

 distinct of the original color ornamentation. Such specimens 

 are, however, extremely rare,f and in the course of an experi- 

 ence which has brought under my observation certainly many 

 hundred thousand examples, the specimen which is the subject 

 of the present note is the only one of which it could be stated 

 positively and unmistakably that the original markings were 

 retained. Even in this instance, however, we can be sure only 

 that the pattern and not the original colors are preserved. 

 The ornamental pattern consists of more or less irregular zig- 

 zag bands, the colors being alternately brown and whitish, and 

 the definition surprisingly distinct. It is quite possible, of 

 course, that the colors of the living shell may have been much 

 less sombre. 



The unique fossil showing this character was collected by 

 Mr. Victor Barnett, near Tobinsport, Perry County, in southern 

 Indiana, in rocks which have been referred to the Chester 

 group. It is clearly a representative of the group of Paleozoic 

 shells commonly referred to the genus Naticopsis, but in its 

 specific relations it appears to be new. It consists of about 

 three rapidly enlarging, regularly rounded whorls, which are 

 deeply embracing so that the spire is quite low and almost the 



* Published by permission of the Direetoi* of the U. S. Geological Survey. 



f The instances which I am able to mention of fossil shells in the Paleozoic 

 retaining color markings are mostly brachiopods and mostly representatives 

 of the Terebratula group. Davidson has figured several of these and recently 

 D. K. Gregor (this Journal (4), vol. xxv, p. 313) has noticed an American 

 species. The Terebratulas are colored in alternate enlarging rays. Kayser, 

 as noted by Gregor, has recorded the retention of color markings on a 

 Devonian Rhynchonelloid, and Waagen has figured two Producti as prob- 

 ably retaining their original color. These are P. abichi and P. serialis, which 

 are represented as of a uniform dark reddish or brownish tint. 



