THE TREMATODE PAKASITES OF FISHES. 



497 



respectively. Pseudocotyle squatinae was found on the skin of Rhina 

 squatina, and Calicotyle Kroyeri was met with in the cloaca of the three 

 rays, Raja circularis, R. maculata and R. davata. A species of Microco- 

 tyle was obtained from the gills of Trachinus draco. Two specimens only 

 were present, and they were not quite mature. Their posterior end was 

 provided with seven suckers on each side. Some similar specimens were 

 collected from the same host at Aberdeen (Fig. 6). They were 

 larger and apparently fully mature. In them the posterior end had 

 eleven pairs of suckers. I am unable to decide whether these two forms 

 are identical or not, and whether both are identical with the Microcotyle 

 draconis obtained by Briot (1904) from the same host. As Briot's work is 

 not accessible to me I am unable to make any comparison of these forms. 

 The probability is that my specimens are identical with those of Briot. 



Descriptions of Calicotyle Kroyeri and Octobotkrium merlangi are to be 

 found by Lebour (1908, pp. 49 and 50). A description of Axine helones 

 will be found by Scott (1911, p. 69). 



LIST OF FISHES EXAMINED AT PLYMOUTH, WITH THE 

 TREMATODE PARASITES COLLECTED FROM THEM. 



1. 



Mullus barbatus. 



Derogenes varicus. 

 Spar us centrodontus. 



Steringotrema pagelli. 



Zoonogenus vividus. 



Derogenes varicus. 



Hemiurus communis. 

 Trachurus trachurus. 



Tergestia laticollis. 



Derogenes varicus. 



Lecithaster gibbosus. 



Hemiurus communis. 



Stomach. 



Intestine. 

 Rectum. 

 Stomach. 

 Stomach. 



Rectum. 

 Stomach. 

 Intestine. 

 Intestine. 



KEW SEIIIES. — VOL. X. NO. 3. OCTOBER, 1914. 



2 I 



