THE NAUTILUS. 115 



panying plate is probably one of the best preserved examples 

 of Swallow's ^^ Trochus^^ missouriensis yet collected, and the 

 ornamental color pattern consists of revolving bands, the outer 

 or peripheric band dark, and the inner (upper) one light. On 

 the base of the shell the color is still better preserved ; a central 

 umbilical space is light, followed by a dark band. This in turn 

 is followed by another light band, and the outside, or periph- 

 eric, band is dark, as on the upper surface. The ornamentation 

 of this species is further increased by a series of still darker 

 curved bands that follow the gracefully curved growth-lines of 

 the shell. 



In his description of this species Professor Swallow states 

 that "the surface is highly polished and beautifully cancel- 

 lated " and that "it still retains its pristine luster." The shell 

 of which he thus wrote is preserved in the University collection 

 (Type No. 928, paleontological collection, University of Mis- 

 souri) and while its surface is highly polished and exquisitely 

 cancellated only a slight trace of the bands of color that orig- 

 inally adorned it are present. 



After removing a mass of oolite by which the base and part 

 of the spire of the figured specimen were concealed, and its 

 beautifully polished surface was revealed, I could well appreci- 

 ate the feeling of the great English paleontologist, Davidson, 

 who in describing a color-marked Brachiopod says : " When we 

 reflect how vivid, beautiful and varied must have been the tints 

 which once adorned the now black and dingy fossils, we are 

 delighted when by some fortunate accident, some remains of 

 that color is faintly preserved upon a shell which has for almost 

 countless ages been concealed from the sight of man." I will 

 not attempt to suggest what the original tints were that adorned 

 this species ; however, the colors as preserved upon the speci- 

 men are a light pearl gray and chestnut brown, in the revolving 

 bands, and in the curved rays following the growth lines a dark 

 chocolate brown to black. 



In the list of references to coloration which follows, the writer 

 has not in any sense attempted a complete bibliography of the 

 subject. Further search through the German and Italian 

 literature, to little of which he has had access, will undoubtedly 

 bring to light other references. 



