136 TRANSACTIONS OF THE WAGNER FREE 



appearance and to angulate the aperture a little in front of the suture on the 

 outer lip ; the varix of the adult is more pronounced than in any specimen of 

 the recent form I have seen, the lirse on the pillar and outer lip are stronger, 

 the aperture narrower, the periphery of the last whorl distinctly flattened, 

 and owing to the margination of the suture the spire has a slightly turrited 

 appearance. 



This varies in size and in the strength of the (usually 13—14) ribs, as the 

 recent shells do, but I have not been able to find a single specimen which 

 exactly reproduces the recent type in any of its numerous variations. 



Anachis avara var. amydra Dall. 

 In this variety, which is less common, the ribs are obsolete or absent and 

 represented only by a band of little knobs which coronate the whorl at the 

 suture, which is not appressed; the spiral sculpture, always present, is in this 

 variety more prominent owing to the absence of the ribs ; the aperture is 

 strongly lirate. This form is found with the preceding, and is nearest some 

 of the mutations of ^. avara var. seviiplicata Stearns of the recent fauna. 



Anachis camax n. s. 

 Plate 12, figure 3. 



Shell slender, elevated, with two small, smooth (usually caducous) nuclear 

 whorls andeightsubsequent reticulated whorls ; spire acute, with flattish sides ; 

 transverse sculpture of (on the last whorl 15) narrow, rounded ribs extending 

 from suture to suture and (on the last whorl) over the periphery, becoming 

 obsolete on the base, and, especially on the later whorls, with much wider in- 

 terspaces ; spiral sculpture of (between the sutures about 5) strong, flattish 

 threads, most marked on the base and interspaces, feeble on the ribs and with 

 subequal interspaces, except the first one in front of the suture, which is wider; 

 whorls flattish, suture distinct ; aperture rather narrow and long; canal short, 

 pillar twisted ; inner lip with a thin callus ; outer lip not much thickened and 

 with a few feeble lirse; lines of growth distinct. Max. Ion. of shell 14.5; of 

 aperture 5.0; max. diam. of shell 4.5 mm. 



Pliocene marls of the Caloosahatchie and Shell Creek. 



This form is longer and more slender and more regularly reticulated than 

 any of the recent forms I am acquainted with. It is, perhaps, most like the 

 strong-sculptured variety of A. iontha Ravenel, but much larger. 



Anachis ithitoma n. s. 

 Plate 12, figure 6. 

 Shell small, slender, thin with a large, smooth, two-whorled nucleus and 

 four subsequent whorls ; transverse sculpture of numerous narrow, nearly 

 straight, rounded riblets, reaching the sutures, but obsolete on the base, with 

 subequal interspaces; spiral sculpture extremely fine and faint or none ; whorls 

 rounded slightly, suture distinct, but not appressed ; base rounded ; canal very 



