THE NATURAL HISTORY SURVEY. 149 



and five or six narrow bands below and one or two above the 



peripheral band; whorls six, convex, rapidly increasing in size; 



aperture very nearly circular; somewhat contracted by the 



reflected peristome, and showing the bands of color through 



the shell; peristome reflected, very thick, white or pinkish, 



with an obtuse tooth on the base; terminations deflected toward 



each other and connected, in some specimens, by a thin callus; 



the reflection near the columella partly covers the umbilicus; 



umbilicus profound and wide, showing all the volutions to the 



apex, which may be easily perforated; base of shell convex. 



Greater diam., 29.00; lesser, 25.00; height, 15.50; umbilicus, 5.00 mill. (10118.) 



" 30.00; " 25.50; " 15.50; " 5.00 " (7731.) 



" 26.00; " 21.50; " 15.50; " 5.00 " (7730.) 



" 31.50; ' 25.50; " 14.50; " 6.00 " (7729.) 



Animal: With a long and narrow body; color light brown, 

 darker on eye-peduncles and head, uppersurface of foot flecked 

 with white; foot thick, long, narrow, acutely pointed behind; 

 eye-peduncles long and slender, cylindrical, the black eyes on 

 prominences at the tip; tentacles short, cylindrical, blunt; re- 

 spiratory orifice large, on the right side under the peristome. 

 The heart is plainly seen just below the largest brown band and 

 about 5 mill, from the aperture. An examination of the pulsa- 

 tions of a dozen individuals gave the following data: 70 (3 spec- 

 imens), 65 (4 specimens), 62 (3 specimens), 58 (i specimen), 

 56 (i specimen). The heart beat much slower when the shell 

 was held tightly in the hand, and much faster (70) when the 

 animal was extended and crawling over the hand. Length of 

 foot 41.00 mill., width lo.oo mill. Another specimen gave 57 

 by II mill. 



Jaw: Strongly arched, ends squarely truncated; ten stout 



FIG. 18. 

 Jaw of POLYGYRA PROFUNDA Say. (Original.) 



ribs on anterior surface which denticulate both margins of jaw 

 (Fig. 18). 



Radula formula: V + V+i+V + V or \ 8 + V+i+ + 

 (40140); central tooth with a squarish base of attachment, 

 much expanded on the lower outer edges; reflected portion 



