SEA-FISHERIES LABORATORY. 299 



The measurements of the largest of these are : — 

 Greatest diameter of head : 1*75 mm. ; 

 Total length of strobila : 10*7 cm. ; 

 Width of widest proglottis : 3 mm. ; 

 Length of widest proglottis : 1*7 mm. ; 

 but this worm is obviously incomplete. 



The shape of the head is very characteristic of this 

 species but identification is made practically certain if the 

 top of the scolex be shaved off and cleared so as to display 

 the hooks. There is one pair of these on the margin of 

 each bothrium and the two hooks of the pair are connected 

 together at their bases. 



Fig. 12 shows the scolex from the side and the same 

 seen from the top. 



Acanthobothrium coronatum, Budolphi. — Fig. 13. 



Hosts : Rata clavata, Carnarvon Bay, and R. batis, 

 off-shore grounds. 



Most of the specimens of this worm were very small, 

 measuring from 5 mm. to 20 mm. One, however, was 

 much larger, and I give the principal measurements as 

 taken from this specimen. 



Length of head : 1*18 mm. ; 

 Greatest diameter of head : 1'16 mm. ; 

 Length of head and neck : o'O mm. ; 

 Diameter of hook apparatus at the apices : 

 024 mm. 



This species is easily recognised by the general shape 

 of the head and the presence of the three large accessory 

 suckers above each bothrium. These accessory suckers 

 are not easily observed in such a view of the head as is 

 represented in fig. 13, but if the latter is propped up in 

 a watch-glass so that one may look down on it from above 

 their disposition can easily be seen. 



