SEA-FISHERIES LABORATORY. 391 



to the outer edge of the zygocardiae ossicle with which it 

 articulates by means of a ligament. 



One pair of Post-pectineal Ossicles (pt. pec.) Each is 

 a narrow rod-like ossicle which passes backwards from the 

 pectineal ossicle to the posterior wall of the stomach. It 

 then suddenly turns downwards and runs down the 

 posterior wall of the cardiac fore-gut as a straight rod. 

 At its lower end the ossicle turns forwards for a short 

 distance. On the internal border of the ossicle there is a 

 row of setae projecting into the stomach. 



The Infero-lateral Cardiac Ossicles (i.l.) are a pair of 

 long rod-like ossicles, each of which lies immediately 

 behind and parallel to the rod-like portion of the post- 

 pectineal ossicle. Dorsally the ossicle is in contact with 

 the sub-dentary ossicle, and ventrally it terminates on a 

 level with the lower end of the post-pectineal ossicle. 

 The ossicle is broader at its upper end and tapers 

 gradually towards its lower extremity. 



There is one pair of Sub-dentary Ossicles (s.dt.) At 

 its anterior end each ossicle is in contact with the inner 

 border of the zygocardiac ossicle. The ossicle passes 

 downwards and backwards as a somewhat curved rod, and 

 its posterior end touches the upper end of the infero- 

 lateral cardiac ossicle. 



The Lateral Cardio-pyloric Ossicles are a pair of small 

 ossicles articulating with the posterior and upper end of 

 the infero-lateral cardiac ossicles. 



Postero-lateral Cardiac Plates (cd. pi.). These are a 

 pair of broad plates roughly quadrangular in shape, each 

 lying in front of the post-pectineal ossicle. It is a 

 membranous area having no decided calcification, but 

 being distinctly thicker than the ordinary wall of the 

 stomach. There are two rows of long setae arranged along 

 the posterior edge of each plate and projecting into the 

 cavity of the stomach. 



