MARPESSA. 185 



MARGINATED. (Margo t edge.) Having an edge or border 

 thicker than the rest of the shell, from which circumstance the 

 litle genus Marginella derives its name. 



MARGINELLA. (A little rim or border.) Fam Columellaria, 

 Lam. Angyostomata, Bl.— Bescr. Ovate, smooth, shining, with 

 a short, sometimes hidden spire ; aperture narrow, emarginated ; 

 columella with several oblique folds ; outer lip neatly reflected. 

 — Obs. This genus of pretty little shells differs from Voluta, 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. Glabella, Sw. 



MARGINULINA. D'Orb. A genus of microscopic Foraminifera. 



MARINE CONCHACEA. See Conchacea. 



MARINE TESTACEA. Those shell-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 number, 

 and in the genera to which they belong. 



MARINULA. King. A genus of small shells resembling Auricula 

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

 entire ; columella bidentate, uniplicated towards the base, with 

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



MARMAROSTOMA. Sw. A genus of "Trochids," Sw. thus 

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

 sed, and obtuse ; inner lip obsolete ; base even more produced 

 than in Senectus, but never distinctly channeled. M. versicolor. 

 Mont. 176. f. 1740, 1741, undulata. Chem. 169. f. 1640, 1641," 

 Sw. p 348. 



MARPESSA. Gray. A sub-genus of Clausilia, C. bidens, &c. 

 Auct. Gray's Turton, p. 212. 



