1918 Bovard and Osterudj on Embryological Material 137 



Chelysoma productus Stimpson. Common in trawling, and known as 

 the horse-shoe ascidian. Large clear eggs were found in the ovaries at 

 the end of the season (August 1917). 



Vertebrata 



Hydrolagus colliei (Lay & Bennett) Gill. Common in trawling, but 

 rarely are the eggs of these found. 



Raja hinoculata Girard. Common skate found in waters of the Sound. 

 The egg cases brought up in trawling during July very often contain a 

 good series from the eggs with the blastodermic disk formed to young 

 with the yolk-sac nearly absorbed. When the trawl brings up these egg- 

 cases it nearly always brings up at the same time six and perhaps more. 

 There may be one to five eggs in a single case, and almost invariably the 

 eggs from the different egg cases may be arranged in a series, thus sug- 

 gesting that the skate lays her eggs all in one place or nest. 



A species of cottoid fish lays large masses of eggs which are clear and 

 stuck together with a gelatinous substance. They may be seen at low tide 

 fastened to the side of rocks. These are found only early in the season, 

 June to early July. 



