DIVISION III. 
ARTICUL AT A. 
The animals of this comprehensive division have their bodies, 
or members, composed of segments or articulated rings, to 
which the muscles are attached, on their interior surface. This 
division contains five classes; namely, Anndides , Crustacea, 
Arachnides, Myriapoda, and Insecta. 
CLASS V.—ANNELIDES. 
Bodies more or less elongated, soft, naked, or inclosed in 
a tube, consisting of a number of segments, and having red 
blood. It contains three orders. 
ORDER I.—SEDENTARLE. 
Animals protected by a testaceous tube, which they never 
leave during life ; branchial placed at one extremity of the body. 
TRIBE I. SEllPULACEA. 
The branchue are either separate, or covered by an operculum ; 
tube solid and testaceous. 
Genus 1. —M A GIL U S. — Lamarck. 
Generic Character. —Shell with its base bent into a spiral 
form, ova), with four contiguous, convex volutions, the last of 
