No. 2.] DEVELOPMENT OF MARINE ANNELIDS. 229 



PART I.— DESCRIPTIVE. 

 A. AMPHITRITE ORNATA verrill. 



Colonies of Amphitrite are found in several places in the 

 vicinity of Woods Holl, Mass., being more abundant at Lackey's 

 Bay, Hadley Harbor, and Ram Island. The animals live in 

 tough mud-tubes, from just below low-water mark to a consider- 

 able depth. A little experience enables one to locate the tubes 

 easily, for every one has two openings, each at the summit of a 

 peculiar mound which resembles a small anthill. The capture 

 of the worms themselves is attended, however, with a good deal 

 of difficulty, since they retreat to a considerable depth beneath 

 the surface of the mud. The limits of the breeding season are 

 unknown. Although about eight hundred worms were collected, 

 in lots of twenty or thirty, between the first of June and the 

 last of August, only seldom were ripe eggs and ripe spermatozoa 

 obtained. Naturally the eggs are not found in the sea, for 

 they are just the color of the mud, and are doubtless discharged 

 free into the water, and soon scattered by the currents. 



The females are darker colored than the males, and the eggs 

 can often be seen through the body wall. It is useless to cut 

 the animals open, for, if the sexual products are mature, they 

 will be discharged, usually at about 6 o'clock in the evening, 

 more often on the day of capture, sometimes the next day. The 

 rarity of ripe specimens is partly compensated for by the enor- 

 mous number of eggs which may be obtained from one female. 

 They may be kept in the sea-water for an hour or more with- 

 out harm, and then successfully fertilized by simply adding the 

 sperm, though it is necessary to rinse the eggs later to rid them 

 of the superfluous spermatozoa. The late larvae, five days old 

 or more, are best kept in a dish with fresh ulva ; the trocho- 

 phores soon lose their cilia and creep upon the sea-weed. 



For killing, I have used Kleinenberg's picro-sulphuric (strong), 

 chrom-formic, Perenyi's fluid (for surface views), and Flemming's 

 fluid, weaker formula. 



My first material was so damaged by the tannin which the 

 alcohol extracted from the cork stoppers that I discarded the 



