ON AMPHILINA PARAGONOPORA 49 



p o r a , as will be stated, is found in a fresh-water fish in the 

 Ganges and Jumna. 



(a) Habitat and External Characters. 



Am phi Una paragonopora is parasitic in the body- 

 cavities of the two closely related spec'cs of Siluroid, 

 M a c r o n e s a o r and M. seenghala^ — the common 

 ' Tingra ' — -found in the Ganges and the Jumna at Allahabad 

 and elsewhere in the United Provinces and in the Panjab, 

 and supplied to the bazaars as food for the lower caste natives. 

 In size the parasite varies greatly according to its stage of 

 growth and the degree of contraction of the body musculature. 

 The largest specimens (two) I have found measured when living 

 (and uncontracted) 280 mm. in length (when preserved the 

 specimens contracted to 170 mm.) and 5 mm. in maximum 

 breadth ; on the other hand, the smallest specimens only 

 measured 10 mm. or 11 mm. in length and 1 mm. in breadth. 

 Specimens measuring 60-70 mm. in length are fairly common ; 

 occasionally specimens are found which are slightly broader 

 in proportion to their length than the above measurements 

 indicate. The parasites are thus distinctly ribbon- or strap- 

 shaped (PI. 3, lig. 1), the thickness being one-fifth to one-tenth 

 of the breadth. There is no scolex, but the ' anterior ' " end 

 tapers slightly, is either rounded or pointed (according to the 

 state of contraction), and carries a short muscular globular 

 or ovoid evaginable organ (PI. 3, fig. 1, k) — the ' proboscis ' — 

 which is not a sucker (acetabulum) and is never used for 



^ The chief distinction between Macrones aor and M. seenghala 

 is that ill the latter the maxillary barbels are much shorter than in the 

 former. These fishes are said to grow to a length of six feet, but my 

 largest specimens did not exceed three feet and the majority were between 

 one foot and two feet ill length. I may add that the food of these fishes 

 consisted of insects (chiefly Orthoptera) and small fishes, and an examina- 

 tion of the tissues of this food fauna may reveal later the intermediate 

 host or hosts of A lu p h i 1 i n a p a r a g o n o p o r a . 



^ I apply the term ' anterior ' to the mobile end of the body possessing 

 the proboscis in a descriptive and not in a comparative morphological 

 sense. 



NO. 265 E 



