THE TOWER SHELL. J ^ 



In Fig. 58, we have a picture of the Tower Shell, 

 Turritella Cooperi, Cpr. , Tur-ri-tel'-la Coop'- 

 er-i, which is likewise a southern shell, found, 

 according to Mr. Hemphill, on the sandy 

 beach, between tides. The shell can hardly 

 be said to have a body- whorl, but consists 

 wholly of a slender, tapering, many-whorled 

 spire. The sutures are distinct, the aperture 

 circular, and the outer lip sharp and thin. 

 The color is yellowish, somewhat spotted with 

 brown; length, two inches. It can hardly be 

 mistaken for any other shell. 

 Fig.ls. Mesalia tenuisculpta, Cpr., Me-sa'-li-a ten- 

 ui-sculp'-ta, is like a minute specimen of the last, and 

 is found on mud flats. Its whorls are rounded, and 

 feebly sculptured by cross-lines. The usual length 

 is less than one-fourth of an inch. 



The next species is wholly different from any that 

 have gone before. It has a shell about one-eighth of 

 an inch long, looking like a minute, slightly-curved 

 tube. Under the microscope it is seen to be com- 

 posed of very numerous and closely-crowded rings. 

 Its color is white or yellowish, and its name is Ccecum 

 Calif ornicum, Dall., Se'-kum Cal-i-for'-ni-cum. 



Ccecum crebricinctum, Cpr., kre-bri-sink'-tum, is a 

 species having a shell twice as large as the last, 

 marked by exceedingly fine rings, which are often 

 quite indistinct. Both of these species are found 

 chiefly in the South. 



Spiroglyphus lituella, Morch., Spi-ro-gly'-fus lit-u- 

 el'la. This singular mollusk has an irregular, tubular 

 shell, which becomes attached to the side of a stone, 

 and twists itself into an ill-shaped, flattened cone. 



