312 



C(ELHELMINTHES. 



bristles of each side are supported by a fleshy outgrowth of the 

 somite, the parapodium, in which two portions corresponding to the 

 bunches of bristles dorsal, notopodium; ventral, neuropodium 

 may be recognized (fig. 281). This is the first appearance of 

 A 



K 



FIG. 281. A, head with protruded phaiynx; B, parapodium of Nereis versipedata. 

 (After Ehlers.) c, cirri; fc, jaws; I, head with eyes; p, palpi; *, tentacles. 



true appendages, but they differ from those of Arthropoda in 

 that they are not jointed to the body nor jointed in themselves. 

 On the dorsal surface may occur diverse outgrowths, known, accord- 



Fia. 282. Ampkitrite ornata* (From Verrill.) 



ing to position or function, as cirri, elytra, gills, etc. ; on the head, 

 palpi and tentacles. The cirri are long processes on the parapodia, 

 and like palpi are tactile (fig. 281). Elytra are thin lamellse 

 which cover the back like shingles and thus protect the body. 



