162 



;\s natural a condition as possible, or to make g-eneral 

 stained preparations of the proglottides. Before pre- 

 serving- it is, however, desirable to rinse the animal A'ery 

 gently in fresh water in order to get rid of the muens and 

 chyle with which it is snrrounded. In the case of many 

 species the strobila generally comes to pieces on being 

 preserved and if tjie whole organism is to be stndied it is 

 necessary to preserve snch worms, each in a separate tnbe. 



I. CESTODA. 



BOTHRIOCEPPIALID^. 



Bothriocephalus ( = Dibothrium) punctatus, Rudolpni. — 



Fig. 11. 



Hosts: Rhombus mtunmiis and R. laevis; at all 

 stations. 



Every tnrbot and brill examined has so far proved 

 to be the host of one or moi-e of this cestode. Generally 

 the brill harbours only two or three Avorms, but in the 

 case of the turbot the number is much greater. One 

 turbot -iOj inches in length, (?auglit in Luce Bay in 

 October, 1905, was greatly infested, and I counted over 

 60 Dihotlirin in the gut exclusive of several which had 

 become detached. All were attached to the walls of the 

 pyloric caeca. 



Two distinct varieties of Dibothriiim punctatus are to 

 be noticed (see fig. 11, A and B), and it is hard to resist 

 the impression that we are dealing here with two distinct 

 species. The general morphology of the scolex and 

 j)rogl()ttides is, hoMever, so similar in both cases that it 

 is probable that we have to deal with varieties only, or 

 at most physiological species, the difference being due 

 to the different habitat. The differences between the two 

 cestodes are (1) the length and thickness of the head and 



