THE NAUTILUS. 101 



Miiller; color very pale ; sculpture weak, consisting of fine lines of 

 growth crossing tlie wliorls somewhat obliquely, the more distinct 

 ones on the last whorl occurring at rather regular intervals, some 55 

 micromillemeters apart. Diameter of last wliorl ahout 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 Firmer a longifolia, Lx. On the 

 same slab as the Planorbis is a small Sphaerium, badly crushed and 

 broken. The 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. 

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

 convex, and, with the same number of wbor?s, is at least twice as 

 large. I take it that P.jlorissanlensis is a Gyrcmlus, which P. cegualis 

 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 Chazy, (lower 

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

 surprised to find two small specimens of Straparollina harpa 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 P. vortex and P. spiror- 

 bis; other species recall P. contorlus. 



