196 MAEM ABO STOMA. 



Angyostomata, IBl.—Descr. Ovate, smooth, shining, with a short, 

 sometimes hidden spire ; aperture narrow, emarginated ; colu- 

 mella with several oblique folds ; outer lip neatly reflected. — 

 06s. This genus of pretty little shells differs from Yoluta, in the 

 reflection of the outer lip. The animal covers the greater part 

 of the shell with the mantle, and by continually depositing 

 vitreous matter gives it a bright polish, which, together with 

 the delicately neat arrangement of colours in most species, 

 renders them exceedingly beautiful. The Marginellse are marine 

 and tropical. A few fossil species are found in the Calc-grossier. 

 Fig. 437. M. Glabella, genus Gtlabella, Sw. Sowerby's Mono- 

 graph in Thesaurus Conchyliorum enumerates 108 species. It 

 will be seen that priority may be claimed for the name " Porcel- 

 lana" for this genus. PI. xx. fig. 437. 

 MAHGrlNULINA. D'Orb. A genus of microscopic Poraminifera. 

 MAEINE CONCHACEA. See Conchacea. 

 MAEINE TESTACEA. Those sheU-fish which inhabit seas, lakes, 

 &c. of salt water, in distinction from the Aquatic Testacea, or 

 those which are found in rivers, ponds or stagnant pools of fresh 

 water : and also from the Land Testacea, which live on land and 

 breathe air. The great proportion of shells belong to the former 

 class, those of the latter two classes being limited in their num- 

 ber, and in the genera to .which they belong. 

 MAEINIJLA. King. A genus of small shells resembling Auricula 

 and Pedipes, described as " Ovate, sub-solid, with aperture ovate 

 entire ; columella bidentate, uniphcated towards the base, with 

 large sub-remote teeth ; the largest uppermost ; no operculum." 

 MARIS A. Grray, 1824. Cekatodes, Gruilding. Amptjliabia 



Cornn-arietis, Lamarck. See our fig. 323. 

 MAEMAEOSTOMA. Sw. A genus of « Trochid^," Sw. thus 

 described : " Umbilicus deep ; spire of few whorls, much de- 

 pressed;, and obtuse ; inner lip obsolete ; base even more pro- 

 duced than in Senectus, but never distinctly channeled. M. versi- 

 color. Mont. 176. f. 1740, 1741, undulata. Chem. 169. f. 1640, 

 1641." Sw. p. 348. The operculum is thick, rounded, and 

 with a canal near the outer edge. 



