SCABRICULA. 251 



SANDALINA. Schum. Crepidulina, Lam. A genus of micro- 

 scopic Foraminifera. 



SANGUINOLARIA. Lam. {Sanguis, blood.) Fam. Nymphacea, 

 Lam. Pyloridea, Bl. — Bescr. Equivalve, inequilateral, transverse, 

 sub-ovate, rounded anteriorly, sub-rostrate posteriorly, compressed, 

 thin, covered with a shining epidermis, gaping at the sides ; hinge 

 with two cardinal teeth in each valve, and an external ligament 

 supported upon a prominent fulcrum ; muscular impressions two 

 in each valve, lateral, irregular, palleal impressions with a large 

 sinus. — Obs. This description is made to exclude some of La- 

 marck's species of Sanguinolaria, such as S. occidens, S. rugosa, 

 which are Psammobise ; and to include others which he has left 

 out. The Sanguinolarise are sub-rostrated posteriorly, while the 

 Psammobiae are sub-quadrate and have a posterior angle. Fig. 98, 

 S. rosea. Sandy shores of tropical climates. 



SARACENARIA. Defr. A genus of microscopic Foraminifera. 



SAVIGN1UM. Leach. A genus of Sessile Cirripedes, described as 

 composed of four valves soldered together, and a convex bivalve 

 operculum ; the ventral and posterior valve on each side being 

 soldered together, in other respects resembling Pyrgoma. 

 Fig. 30. 



SAXICAVA. Fl. de Belvue. Journ. de Ph. an. 10. (Saxum, a 

 stone ; cava, a hollow.) Fam. Lithophagidse, Lam. Pyloridea, 

 Bl. — Bescr. Transverse, irregular, generally oblong, inequilateral, 

 sub-equivalve, gaping anteriorly ; ligament external ; muscular 

 impressions two, lateral ; palleal impression interrupted, not 

 sinuated; hinge, when young with sometimes two or three minute, 

 obtuse, generally indistinct, cardinal teeth ; which become obso- 

 lete when full grown. — Obs. Several genera have been founded 

 only upon the difference between the young and old shell of the 

 same species of this genus. The Saxicavse are found in the little 

 hollows of rocks; in cavities on the backs of oysters, of roots of sea- 

 weeds, &c. in northern and temperate climates. S. rugosa, fig. 94. 



SCABRICULA. Sw. A sub-genus of Mitrse, consisting of species 

 which have a roughened external surface, &c. Sw. Malac. 

 p. 319. 



