TIIE NAUTILUS. 101 



Mu'ller; color very pale ; sculpture weak, consisting of fine lines of 

 growth crossing t lie wliorls somewhat obliquely, t lie more distinct 

 ones on the last whorl occurring at rather regular intervals, some Ijo 

 micromillemeters apart. Diameter of last whorl about three times 

 that of penultimate ones. 



Hah. — Oligocene beds at Florissant, Colorado, collected by Judge 

 J. Henderson and Dr. F. Ramalley, of the University of Colorado, 

 1905. The exact locality is southwest of Florissant, in plant-bearing 

 beds, containing among other things r loner a tongifolia, Lx. On the 

 same slab as the Plauorbis is a small Spftaerium, badly crushed and 

 broken. Tlie Planorbis is not very well preserved, but I believe that 

 it will be readily recognized from the above description. Of the 

 species belonging to the same geological period, it is most like P. 

 sequalis White, from Wyoming ; but that species appears to be more 

 convex, and, with the same number of whorls, is at least twice as 

 large. I take it that P.jlorissantensis is a Gyrmilus, which P. agnail's 

 does not seem to be. It is rather curious that several of the fossil 

 species of Planorbis found in America remind one rather of European 

 forms, than of those living in this country to-day.* Possibly the 

 dominant Planorbis of modern America may represent in part an in- 

 vasion from the south, which has displaced some of the older types. 



Scudder (Tertiary Insects of N. America, p. 31), mentions a 

 Planorbis from Florissant, probably the species now described. 



AN ORDOVICIAN GASTROPOD RETAINING COLOR MARKINGS. 



BY PERCY E. RAYMOND. 



While examining some small fossils collected in the Chazv, (lower 

 Ordovician), limestone at Valcour Island, New York, the writer was 

 surprised to find two small specimens of Straparollina Ion-pa Hudson, 

 which retain with remarkable distinctness the lines of color mark- 

 ings and possibly some trace of the original colors. The specimens 

 are very small, the larger being less than one quarter of an inch in 

 diameter. The body color of the shells is a light yellow, which is 

 the prevailing color of the fossils in the particular stratum from which 

 these specimens were taken. Around the top of the body-whorl, ad- 



*Thus, P. cirratus White is extremely suggestive of/', vortex and P. spiror- 

 bis; other species recall P. conlorlus. 



