SEA-FISHERIES LABORATORY. 219 



pointed or flattened into a disc (Plate I., fig. 4). This is 

 the " chalimus " stage referred to on previous pages, so 

 called because Burmeister, in 1831,* described it as a new 

 genus under the name " Chalimus." This was afterwards 

 shown by Hesse and others to be only a young stage of the 

 Caligidse. The young parasite continues to grow by suc- 

 cessive moultings, and the various appendages make their 

 appearance in regular order. The duration of this 

 attached stage has not been determined. When the 

 appendages are fully developed, as in Plate I., fig. 6, the 

 filament separates at its junction with the frontal margin 

 leaving a notch, the remains of which persist all through 

 the adult life. 



The male, at the conclusion of the attached stage, is 

 practically fully developed. The female remains in an 

 immature condition until fertilisation is effected and the 

 ova begin to pass down the oviducts. The genital seg- 

 ment then increases in size from that shown on Plate II. , 

 fig. G, to the mature condition of Plate I., fig. 1. 



/ 



* Nov. Act. Acad. Natur. Cur. Bonn., vol. xvii., p. 294 



