322 MALACOZOA. CEPHALOPODA. FOBAMINIFERA. 



to be distinct and undescribed, I have named it after Mr. 

 Alexander Davidson. 



Found by me, in December, 1842, in shell sand, from Cru- 

 den Bay, sent by Mr. Alexander Murray. 



3, Dent alma rectiuscula. Straiyhtish Dent aline. 



Shell subarcuate, slightly tapering, somewhat com- 

 pressed, of twelve slightly convex, smooth, even, some- 

 what oblique cells, the uppermost much larger, with a 

 small circular aperture. Rectiusculus, straightish. 



Shell arcuate in various degrees, somewhat compressed, 

 tapering a little toward the lower end, which is rounded ; of 

 twelve slightly convex, smooth, transparent, somewhat oblique 

 cells ; the uppermost cell much larger, oblong, oblique, nar- 

 rowed anteriorly, and having a small circular aperture directed 

 somewhat toward the concave side of the shell; the colour 

 hyaline-white. Length two-twelfths of an inch, breadth a 

 fifth of the length. 



All the species of Dentalina are essentially more or less 

 curved, and the present, not being by any means straight, 

 cannot with propriety be named "recta." A discoverer, it 

 seems to me, has no right to misname an object; and there- 

 fore I have modified the specific name given by Montagu. 



Found by me, in December, 1842, among shell sand from 

 Cruden Bay, sent by Mr. Alexander Murray. 



Nautilus rectus. Mont. Test. Brit. 197. PI. 19. f. 4, 7. Nodo- 

 saria Dentalina. Lamk. Syst. vii. 596. Ortnocera recta. Flein. 

 Brit. Anim. 236. 



GENUS 2. VAGINULA. VAGINULE. 



Shell linear, much compressed, somewhat tapering, 

 straight or slightly arcuate, composed of numerous ob- 

 lique cells, disposed in a single series, the last cell a 

 little elevated ; aperture small, submarginal. Vagmula y 

 a little sheath or scabbard. D'Orbigny. 



This genus differs so little from Dentalina, that the 

 two might well be united* 



1. Vaginula Legumen. Common Vaginule. 



Shell subarcuate, considerably tapering, compressed, 

 of nine slightly convex, smooth, oblique cells ; the upper 



