68 ANTERIOR. 



ANNULATED. (Annus, a ring.) Composed of, or surrounded by 

 rings, as in the ease of Tubicinella, fig. 14. 



ANODON. Brug. Fam. Submytilacea, Bl. Nayades, Lam. A genus 

 composed of such species of Nayades as are destitute of teeth 

 on the hinge. Europe, North America, &c. An example is given 

 in A. Cataractus, fig. 152. 



ANOMAL1NA. D'Orb. A genus of microscopic Foraminifera. 



ANOMIA. Fam. Ostracea, Lam. and Bl. — Desc?\ Irregular, in- 

 equivalve, sub-equilaternal, foliaceous, pearly within ; adhering 

 to marine substances by means of a bony appendage, which passes 

 through a large circular opening in the lower valve ; muscular 

 impression divided into three irregular portions ; hinge destitute 

 of teeth with a short cartilage, — Obs. The Linnsean genus in- 

 cluded not only the shells to which the description above given 

 would apply, but also many other genera, such as Crania, Orbicula, 

 Terebratula, &c. which belong to the Brachiopoda, and are per- 

 fectly distinct. The AnomiaB are found in Europe, N. America, 

 Moluccas, Philippine Islands, &c. Fig. 186, in the plates, is a 

 somewhat reduced representation of a full grown specimen of 

 A. Ephippium. Fig. 187, the hinge of the under valve, with the 

 bony process. Fig. 1S8, the hinge showing the opening through 

 which it passes. 



ANOSTOMA. See Anastoma. 



ANSATES. Klein. A genus formed of those species of Patella 

 which have a produced, recurved beak. Helcion, Montf. Ex. 

 Patella pellucida, fig. 230. 



ANSULUS or ANSYLUS. Mr. Gray conjectures that the name of 

 the genus Ancylus, should be so written. 



ANTENOR. Montf. A genus of microscopic Foraminifera. 



ANTERIOR. In Bivalves is the side on which the head, or part 

 analogous to the head of the animal lies ; it is known in the 

 shell by the umbones, which if turned at all, are turned towards 

 that part. If there be a sinus in the impression of the mantle, 

 it is always on the posterior part of the shell. If the ligament 

 be placed only on one side of the umbones, it is only on the 



