SEA-FISHERIES LABORATORY. 



81 



The scolex is represented in fig. 2. There are four very 

 prominent bothridia each of which, projects well out from 

 the neck. 



The latter is very short. There are no accessory 

 suckers at the summits of the bothridia. Each of the latter 

 is really divided into three loculi by two transverse, curved 

 costae, but the most anterior loculus is long, about twice 

 the length of the two posterior ones, and it is not apparently 



Suctorial JDart 

 of Both Hum 



Fig. 2. Prosthecobothrium dujardinii, (van Beneden). A, the scolex ; 



B, diagram of one bothrium, seen from the side ; C, the hooks. 



A and C mag. 76 dia. ; B mag. 154 dia. 



concave transversely. The most anterior costa is very 

 prominent, and the second one difficult to see. There 

 appears to be only one loculus, but close examination 

 shows that a costa is concealed in this deeply concave 

 double loculus. This is shown in fig. 2 A, and the diagram, 

 fig. 2 C. It forms a cup-shaped structure- the " appendice 

 tres-motile qui a la forme d'un feuille " of van Beneden. 

 The bothrium is thus essentially similar to that of 



