54 CEYLON PEARL OYSTER REPORT. 



were unable to make out the anatomy of these, as it seemed the material was not very 

 well preserved. 



The diagnosis of Tetrarhynchus carcharidis is as follows : 



Minute, some 9 millims. Anterior end of body very fine and whip-like. Head 

 small, proboscides very fine, with backwardly directed spines, not hooks ; lappets with 

 simple edges, not wrinkled ; proboscis-tubes very coiled, proboscis-bulb one-fifth the 

 length of head. Eighteen or nineteen proglottides, separated by clear, transparent 

 partitions, at first very narrow from front to back. The last two attain a length 

 of 1*5 millims. and of 2 millims., and a width of 0'5 millim. 



Habitat : Carcharias melanopterus, in the intestine. 



CHILOSCYLLIUM IKDICUM (GMEL.). 



This fish is termed " Kurakan sura " in Tamil. 



A. female, sexually mature, and having an egg capsule in each uterus, was caught 

 on the North Modragam Paar, Ceylon pearl banks, on February 3, 1905. The stomach 

 contents consisted of small fishes. 



Carpobothrium, n. gen. 



A minute form, belonging to the Phyllobothriidse. The head consists of four 

 stalked bothridia, each ending in a circular, flat area, from which project two 

 processes, which are opposed to one another. One of these is obcordate in outline. 

 The body is coiled, with little or no neck, the cuticle very crinkled. 



Carpobothrium chiloscyllii, n. sp. Plate III., figs. 38 and 39. 



These peculiar and minute little tape-worms were taken from the intestine of a 

 Chiloscyllium indicum, the common " dog-fish " of the Indian Ocean, on the North 

 Modragam Paar, Ceylon. They are short and in all cases coiled forms, the whole 

 animal being twisted up into a bunch not more than 1 millim. by 0*5 millim. 



The head is remarkable for four long arms which end in four remarkable suckers. 

 The arms stand out at right angles to one another and to the neck ; they consist of a 

 stalk terminating in a very peculiar bothrium. The stalk is capable of considerable 

 extension. In a sketch made from a living specimen each of the four stalks are 

 extended till they attain a length of about one-sixth the total body length and have 

 parallel sides. In the preserved specimens the stalk is contracted and conical. Each 

 stalk ends in a circular, slightly concave area, from the centre of which emerge two 

 processes, slightly flattened and opposed to one another. The process which is nearer 

 to the centre of the head is obcordate like a violet leaf, the second process is rounded. 

 Around the base of these is a ring of muscle fibres, which is, however, broken into 

 two halves, as is shown in Plate III., fig. 39. The bothridia are very mobile, and 

 take up different outlines in different specimens. 



