EGG-LAVING HABITS OF AMPHITRITE ORNATA VERRILL. 335 



ments that serve as moving valves to pump the water slowly 

 through the tube. This pumping action may be demonstrated 

 by placing a recently captured, uninjured worm in a U-shaped 

 glass tube of suitable size. When Amphitritc is about to deposit 

 its eggs the movements become more rapid and frequently more 

 violent than usual. Quoting from my notes, the further process 

 is somewhat as follows : " While the worm's body is undergoing 

 the series of slow peristaltic movements, consisting of contrac- 

 tion-waves that begin near the posterior end and travel forward, 

 the eggs ooze out in string-like, sticky masses that are soon scat- 

 tered by the movements of the body, or by currents of water. 

 The eggs are extruded through five openings in the anterior 

 region of the body, the first opening being on the second seg- 

 ment back of the third pair of gills, or the sixth body segment, 

 not counting the prestomium. Sperm is extruded through sim- 

 ilar openings of the same number and location." These open- 

 ings are nephridiopores that have become specialized as gona- 

 ducts, and it should be added that they are laterally placed, 

 lying between the dorsal and ventral chaetigerous lobes. 



In a previous paper I have mentioned the fact that the eggs 

 are greatly flattened in the polar diameter at the time of extrusion, 

 and that the first polar spindle is in the metaphase. I have also 

 mentioned above the fact that these worms possess the power of 

 separating ripe and unripe eggs in the process of oviposition. 

 How is this accomplished ? Some dissections were made in an 

 attempt to answer the question. It was found that this species 

 possesses the same general arrangement of internal organs as 

 that of other Auiphitrite described by Meyer ('87). " Alle Ne- 

 phridien der Terebelloiden, sowohl die vorderen als die hinteren, 

 miinden im Bereiche desjenigen Korperzonites, welchem sie an- 

 gehoren, einzeln und unabhangig von einander nach aussen ; ihre 

 Wimpertrichter haben eine intersegmental Lage und offen sich 

 stets in das nachst vorangehende Segment." All the septa in 

 the Terebellidae are incomplete with one exception ; this one, the 

 diaphragm, is strongly developed and separates the anterior 

 region of the body cavity from the rest. In the species here 

 described the diaphragm is between the fourth and fifth body 

 segments. The external openings of the excretory nephridia open 



