98 annt:lida. 



of Nereis, and the reduced parapodia provided with simple setae. 

 Notice the characteristic collar on the fifth somite, and the 

 funnel at the posterior end, with the anus within it. The mouth 

 is more or less ventral and is overhung by a narrow prostomium 

 surrounded by a peristomial rim. 

 A draiuing is desirable. 



ARENICOLA CRIST ATA. 



This remarkable worm, called the ''lug- worm" by fisher- 

 men, belongs to the family Arenicolidse. 



1. Notice the color, and the gradual diminution in size pos- 

 teriorly. Also notice the false annulations between the appen- 

 dages, the arborescent gills representing modifications of certain 

 notopodia, the reduced parapodia, and the character of the setae. 



2. If the buccal region is everted, observe the papillae which 

 cover it. The prostomium is an inconspicuous dorsal knob and 

 it is fused with the peristomium. At the sides of the prostomium 

 is the ciliated nuchal groove. 



3. On what somites can you find indications of neuropodia? 

 of gills? of setae? Notice the cirriform papillae of the "tail." 

 Find nephridiopores on certain somites about an eighth of an 

 inch below each notopodium. What is the distribution of the 

 pores? 



A drawing is desirable. 



Gamble and Ash worth: The Anatomy and Classification of the Areni- 

 colidai with Some Observations on their Post-larval Stages. Quart. 

 Jour. Mic. Sci., 43, 1900. 



SABELLA MICROPHTHALMA. 



This worm belongs to the family Sabellidae. It builds leath- 

 ery, muddy tubes on piles, among tunicates, algae, etc. 



1. In addition to the general size, form, and color of the 

 worm, observe the reduced condition of the parapodia, and the 

 arrangement and general structure of the branchice or gills. These 

 structures are modifications of the palps and not of the parapo- 

 dia, as in the other species which have been studied. Observe 



