372 



ARTICULATA: WORMS. 



FIG. 506. 



Marine Worm, Autolytus cornutus, A. Agasaiz. 



A, an asexual individual from which a male is about to separate enlarged six 

 diameters. A, antennje; C, tentacles; F, intestine ; il, setfe. 



B, part of a female enlarged ; 6, eye; e, eggs; /, intestine; 3, one of the appendages 

 of the anterior region of the body; c, dorsal cirrus; li, setigerous tubercle. 



in the bodies of other animals. They vary greatly in 

 FIG SOT form, size, structure, and habits so greatly that 

 naturalists have classified these low articulates 

 in various ways. And it may be added here 

 that in most cases the very young worm is 

 quite different from the parent. 



Young F r our present purposes we recognize the 



worm. Class of Worms or Yermes or Annulata as divis- 



Terebella. 



ible into two Sub-classes : 



I. ANNELIDA, including the more typical forms, together with 

 Gephyrea ; as Errantia or Dorsibranchiata (Lob-worms, etc.) ; 



