.128 Pub. Puget Sound Biol. Sta. Vol. 2, No. 42 



reproductive phase. Some forms, like the echinoderms, have passed their 

 egg-laying period before the Station opens, so that usually only a few 

 belated forms may be observed. Others, as the coelenterata, are abund- 

 ant, and present wonderful opportunities for work with the eggs of me- 

 dusae and ctenophora. The same is true of the ascidians. In still other 

 groups the season is too early. However, the University of Washington 

 plans sometime soon to keep the station open throughout the whole sum- 

 mer; this will greatly extend the possibilities for embryological work, so 

 that many forms not in this list may be discovered. 



Porifera 



Grantia (?). Common on the piles and floats near the laboratory 

 and in the hauls with the trawl, June to August. Individuals kept in the 

 laboratory failed to discharge eggs or larvae, but eggs were easily obtained 

 from teased material. 



Esperella adhaerens Lambs. Abundant on Pecten shells, from June 

 to August. Eggs obtained 1917, but none showed signs of development. 



Myxilla parasitica Lambs. Abundant on Pecten shells brought up 

 by trawl during month of July. Eggs were obtained, but none were found 

 in process of development (1917). 



Coelenterata 



The eggs of the medusae given below may be obtained and fertilized, 

 when the adults are mature, merely by leaving a number of individuals 

 in a dish of water for one to several hours. Many lay eggs at night. The 

 tggs will be found on the bottom of the dish, or floating if the water is 

 sufficiently agitated by the movements of the medusae. 



Phialidium gregarium Haeckel. Abundant in Friday Harbor and eas- 

 ily obtained from docks in front of the laboratory, June to August. Eggs 

 may be obtained in quantity and are large and transparent. Thq hydroid 

 was raised in 1917 by Mrs. T. C. Frye, and proved to be Clytia incon- 

 spicua (Forbes) Eraser. 



Sarsia rosaria Haeckel. Common in Friday Harbor and can be ob- 

 tained from docks in front of the laboratory, June to August. During the 

 summer of 1918 they were less common than in 1917. They vary greatly 

 in numbers from day to day. The eggs are large and clear, and cleavage 

 is easily followed. The hydroid was raised in 1917 by M. C. Riddle, and 

 proved to be a Syncoryne. 



Stomatoca atra Agassiz. Common in Friday Harbor, and may be eas- 

 ily obtained from the docks in front of the laboratory, June to August 

 It was fairly abundant during the summer of 1917, and less so in 1918. 

 The number of individuals is variable from day to day. The eggs are 

 rather small and with yolk, so they are not transparent. Individuals lay 



