108 Till. NAUTILI S. 



of /'. auriculata; a conspicuous pit penetrates under the parietal 

 fold. Striation fine but regular and equally developed above and 

 below. Size about that of typical uvulifera. 



Alt. 6f, greatest diameter 1 I', mm. 



Alt. 6, greatest diameter 1 I urn. 



Alt. (I. 1 ,, greatest diameter 13 nun. 



Aripeka, Hernando Co., Fla. (Mr. Geo. Pine); Hernando Co. and 

 Longwood, Fla. (Mr. Van Hyning's coll.). 



This form resembles /'. auriculata at first sight, hut the deep notch 

 in tli" basal lip near its inner end. and the peculiar, flat, forward- 

 running inner end of that lip. as well as the strong semicircular ridge 

 on the parietal margin, one end of which enters the dee)) notch men- 

 tioned, the other forming the lower border of the main parietal fold 

 — all ally it rather to P. uvulifera. In P. auriculata there is no such 

 notch in the basal lip, and the inner end of the latter is attenuated. 

 not flattened and bent forward. It is an interesting intermediate 

 form. 



P. uvulifera varies a good deal in texture, color, size and striation, 

 the largest and most solid shells before me being from Long Key. the 

 type locality, where they are nearly smooth, t he striation obsolete; 

 diam. 13—14 mm. I have seen a gnat many specimens from both 

 sides ( ,f the peninsula and the keys, hut saw no variation toward the 

 variety described above. 



In most localities P. uvulifera diverges from the '• historic type," 

 as found on Long Key. in being less chalky, ami decidedly more 

 Strongly striate, the stria- thread-like. The size varies with locality. 

 Thus at Miami, where it is numerous about a mile up the river on 

 the south side, they measure ',) to 1()1 mm. diameter. They occur 

 here under stones (limestone) in a hot, sparsely-wooded plain exposed 

 to the sun. in company with P. cereolus carpenteriana, Urocoptis, 

 Macroceramus and Ohondropoma with an occasional Vaginulus, and 

 moderate numbers of large black scorpions and tarantulas. At Palm 

 Beach they are much larger, diam. 12^-13 mm., and here the soil is 

 sandy, and the forest luxuriant. 



Mr. Pine sent numerous specimens of uvulifera from Hernando 

 Co. which differ from the Long Key types in being strongly striate 

 and smaller. They are more narrowly umbilicated than P. uvulifera 

 bicornuta, with tic opening rather less contracted, the umbilical 

 groove on the last whorl generally less strong, and they want the 

 accessony '• horn " of the parietal margin. They are also more 

 coarsely striate, and may he separated from young or immature bicor- 

 nuta by the narrower umbilicus. I do not know whether these occur 

 with the variety or at separate stations. The largest sent measures 

 1 2 nun. diameter. 



P. auriculata extends some distance down the east coast, and over 

 to the middle of the State in the lake region. 1 have never seen it 

 from the west coast counties, and would be glad to have data on its 

 occurrence there if it has been found. 



