WORMS 



181 



calcareous tubes ; these are often found on rocks, in coral, and 

 in the shells of mollusks. The anterior end of the body is more 

 highly developed than the posterior end. 



FAMILY SPIONIDJE 



GENUS Nerine 



N. agilis. Two to three inches long ; slender ; somewhat flattened 

 at the anterior end ; head conical and sharp ; the two tentacles about 

 one half of an inch long ; four eyes ; color reddish-brown, light green 

 on the sides ; gills red ; tentacles greenish- white. It burrows with ex- 

 treme rapidity and lives on exposed beaches near low-water mark. 



N. coniocephala. Two and a half inches long, one sixteenth of an 

 inch in diameter ; head conical ; body flattened on the dorsal side, round 

 on the ventral side ; has two long tentacles turned backward and a mem- 

 brane on the gills of the anterior segments ; gills red ; bristles long and 



numerous. 



FAMILY CIRRATULIDJE 



Worms of this family have a cylindrical body, more or less atten- 

 uated at each end ; segments similar throughout ; many segments 

 with long, filamentous 

 cirri which act as gills ; 

 and a conical head. 

 They live in burrows. 



GENUS Cirratulws 



C. grandis. Four to 

 six inches long; head 

 acute ; segments numer- 

 ous, short, and distinct; 

 color dull yellow, or 

 orange, to brown, often 

 iridescent beneath ; ven- 

 tral surface somewhat 

 flattened. Numerous 

 long, filamentous, red to 

 orange-colored cirri ex- 

 tend nearly the whole 

 length of the body and 

 act as gills. It is com- 

 mon in sand and gravel 

 at low-water mark from 

 Cape Cod to New Jersey. 



Cirratulut grandis. 



