70 CEYLON PEARL OYSTER REPORT. 



If) millims. in length by about 0'5 millim. in breadth, but in the absence of the head 

 they could not be identified. Specimens of T. herdmani described under Trygon 

 walga were also taken from this fish. 



SPHYK.EXA COMMERSONI, Cuv. and Vai, 



This is the sole genus in the family Sphyrsenidse. The species are often called 

 " Barracudas"; they are large voracious fishes living in the tropical and sub-tropical 

 seas. 



Tetrarhynchus, sp. Cysts : 



A considerable number of large Tetrarhynchid cysts were taken from the 

 abdominal cavity of a Sphyrcena commersoni. 



The cysts are large forms varying in length between 8 millims. and 30 millims., 

 with a breadth of about 3 millims. They belong to Vaullegeard's T. erinaceus 

 series, being enclosed in a vesicle as well as in a cyst, which latter is apparently 

 formed by the tissues of the host. The teeth were very crowded, and the excretory 

 opening was visible, but little else could be made out. 



TRYGON KUHL1, Muller and Henle. 



This large ray is called in Tamil, " Ktttti tirikhai." 



Two individuals were dissected ; the first captured off Dutch Bay, the second 

 caught on the pearl bank known as South Modragam Paar. 



From the stomach contents of these two it would appear that the food consists 

 almost exclusively of small annelids and small crustaceans. In the first named the 

 stomach was distended with a large mass of Lumbriconereids, mingled with which were 

 a few thin-shelled small crustaceans. In the second specimen the material was wholly 

 annelidan Terebella, Lumbriconereis, Eunice, &c. 



Phyllobothrium blakei,* n. sp. Plate V., figs. 72 and 73. 



Some half a dozen specimens of this minute worm were taken from a Trygon kuhli 

 captured in the pearl banks. Half of these were without heads. They are very 

 delicate, thin, fragile creatures, measuring 10 millims. in length of the body, and 

 at their greatest width some 0*25 millim. to 0"33 millim. 



The head measures something over 0'5 millim. It consists of four crumpled 

 bothridia with thickened edges, which are so twisted that they show numerous 

 little bays and rounded recesses which at first sight might easily be taken for small 

 circular suckers. These bothridia spring with practically no stalk from the edge 

 of a hollow which shows some circular markings as if there were here two rings 

 of circular muscles. There is no kind of armature. 



The proglottides immediately following the head are broader than the subsequent 



* Named in honour of H.E. Sir Henry Blake, K.C.M.G., the present Governor of Ceylon. 



