GASTHOCH^NA. 159 



not sinuated ; ligament small, partly internal, partly external, 

 fixed on a prominent fulcrum. — Obs. The wide hiatus in the 

 ventral margins of this equilateral shell prevents the possibility 

 of confounding it with any other. Four or five recent species 

 are known, one of which is found on the coast of SicUy, and also 

 in the British Channel. Fam. " KeUiad*." G. Tui-toni. PL 

 ii. fig. 28, 29. 



GrALEEICTJLUS. {Galericulum, a Httle cap or bonnet.) Velu- 

 TiKA, Auct. fig. 337. 



G-ALEEIIS. Humph. Species of Caitptb^a, Lam. "With an 

 obliquely spiral septum. Ex. C. Chinensis. 



GAPING. {Hians.') Bivalve shells are said to gape when the 

 margins do not meet all around. Ex. Gastrochsena, fig. 52. 



GASTEEOPODA. Lam. {Vaarrip, gaster, belly; ttovq, ttoUq, 

 pus, podos, a foot.) The second order of the class MoHusca, 

 Lam. containing those moUuscous animals whose organs of 

 locomotion are ventral. Most of the shells belonging to this 

 order are patelliform, placed upon the back of the animals, 

 which rest or crawl upon the belly. This order is divided into 

 Pneumonobranchiata, that is, those which breathe air, or land 

 moUuscs ; and Hydrobranchiata, or those which breathe water, 

 marine or fresh-water moUuscs. Eig. 227 to 263. 



GASTEEOPTEEA. Meckel. A genus of Bullidae without any 

 sheU. 



GASTEANEA. Schum. ? Cokbula, Act. 



GASTEIDEA. ? Pseudoliva Swainson, 1840. Ebuma plumbea. 

 Sowerby. PI. xxvi. fig. 547. 



GASTEOCHiEIS'A. Spengler, 1780. {TanTrip, gaster, beUy.; 

 Xaivw, chaino, gape.) Fam, Pholadaria, Lam. Pyloridea, Bl. 

 ■ — Descr. Equivalve, regular, inequilateral, with a wide, oblique, 

 ventral hiatus, inclosed in a curved pyriform tube. Differing 

 from Galeomma in being a free, oblique shell ; from Eistvdana, 

 in the oval shape of the valves, and the curve of the tube ; from 

 Aspergillum and Clavagella, in both valves being free. — Obs. 

 The Gastrochaenae are found in the hoUows of massive shells or 

 other marine substances. G. Modiolina. PL ii. fig. 62. 



