ZURAMA. 291 



of a spiral shell. The last whorl is called the body-whorl. The 

 whorls are described as non-contiguous, when they do not touch 

 each other ; continuous, in the opposite case. Depressed when 

 they are flat. They are anyidated, heeled, or coronated ; distinct, 

 or indistinct. They are sometimes, as in Cypraea, hidden by the 

 last whorl. 



XYLOPHAGA. Sow. (£v\ov, zylon, wood ; </;ay w, phayo, to eat.) 

 Fam. Tubiscolse, Lam. — Descr. Equivalve, globose, closed at the 

 back ; with a large, angular hiatus in front ; hinge with a small 

 curved tooth advancing from beneath the umbones in each valve. — 

 Obs. This shell, which is found in a cylindrical cavity, eaten 

 in wood by the animal, resembles Teredo, but has not the shelly 

 tube, nor the posterior hiatus. X. dorsalis, fig. 50, 51. 



XYLOTRYA. Leach. Xylophaga, Sow. 



ZONITES. Montf. A genus formed of Helix Algira, and other 

 similar species with depressed spires and large umbilici ; included 

 in the sub-genus Helicella. Fig. 279. 



ZUA. Leach. A genus described as differing from Bulinus in having a 

 polished epidermis, and a thickened, not reflected lip. Zua lu- 

 brica, B. lubricus, Auct. 



ZURAMA. Leach. A sub-genus of Helix. H. pulchella, Auct. 

 Gray's Turton, p. 41. 



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