LEPIDONOTUS SQUAMATUS. DIOPATRA CUPREA. 81 



LEPIDONOTUS SQUAMATUS. 



The family Polynoidae, to which this belongs, can be distin- 

 guished from all others by the presence of peculiar plates (elytra) 

 on the dorsal surface. They lead sluggish lives under stones 

 and are carnivorous. Note the size, color, and shape of the 

 worm. 



1. The elytra. How are they arranged? What purpose 

 do they serve? How many are there? With a hand-lens ob- 

 serve the fringed condition of the outer edge and the small tuber- 

 cles covering the surface. Note the color of the elytra and the 

 notches in the inner edges of the posterior pair. L. suhlcevis 

 differs in that its elytra are merely punctate and the posterior 

 pair are not so deeply notched. 



2. The head is hidden by the first pair of elytra. If the ely- 

 tra are removed you will find a small reddish prostomium with 

 a pair of eyes, three tentacles (the middle one large and club- 

 shaped), and a pair of palps. 



3. Find the mouth, which is placed ventrally. Note the 

 median, red streak along the ventral surface that is due to pig- 

 mented cells which surround the nerve cord. If the pharynx 

 is everted, observe the fringe of papillse surrounding a dorsal 

 and a ventral pair of teeth. There are no septa in the anterior 

 region of the body where the withdrawn pharynx lies. 



4. The anus is dorsally placed, and can be found beneath the 

 notches in the last pair of elytra. 



A drawing is desirable. 



DIOPATRA CUPREA. 



This worm belongs to the family Eunicidae. Specimens 

 live on mud- and sand-flats, sometimes above low-tide mark, 

 but usually where the burrows are covered by water. This 

 form is especially interesting because of its feeding and tube- 

 building habits, parapodial gills, and complex jaw- apparatus. 

 Study the preserved specimens for the structure and specimens 

 in an aquarium for the habits. Notice the construction of the 

 tube and determine how it is formed. 

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