290 Memoirs of the Indian Museum. [Vol. VII, 



fasts" would be very effective in assisting close union if, as we suggest, they are em- 

 braced by the sucker. 



Heterakis longecaudata, v. Linst., 1879. 



This species, which is very closely related to the genotype, H. papulosa, appears 

 to have been recorded up to the present only in its type-host, Megacephalon maleo, 

 a bird of the Megapodiid family, found in Celebes. It is not improbable, however, 

 that its exceedingly close resemblance to H. papulosa has led to its being often con- 

 fused with that species when found in other hosts. In the Zoological Garden, Calcutta, 

 it occurred in the following birds: — 



Monâl (Lophophorus impeyanus) . 



Crimson horned pheasant (Tragopan satyra). 



Swamp-partridge (Francolinus gularis). 



Red spur-fowl (Oalloperdix spadicea). 



In the two first-mentioned hosts it appears to occur not uncommonly, though in 

 small numbers, if we may judge from the small amount of material available. In 

 the horned pheasant it sometimes occurred together with H. bosia or H. isolonche, or 

 both. In the monâl both longecaudata and isolonche occur, but we have not found 

 them together. 



It may be useful to amplify somewhat the short original description given by von 

 Linstow (1879). The measurements here given are based on examples from the 

 monâl. 



The length of the male is from 79 to 9*1 mm., that of the female 7*9 to 9*6 mm. 

 The maximum thickness, measured dorso-ventrally, is 0*3-0-4 mm. The cuticular 

 striation is so fine as to be scarcely visible in some specimens. The anterior end of 

 the worm is usually curved towards the dorsal side. The three lips are simple and 

 very similar to those of H. papulosa. The diameter of the head at the base of the 

 lips is 0*08 mm. There are well-developed lateral alae, commencing at a short dis- 

 tance from the head, and running throughout the greater part of the length of the 

 body. At 0*55 mm. from the anterior end a pair of small cervical papillae project 

 into the alae. The Oesophagus, measured from the anterior end of the worm to the 

 back of the bulb, is ro-n mm. long. It commences with a small anterior section, 

 or "pharynx," narrower than the oesophagus proper and 0-08-0*09 mm. long. Pos- 

 teriorly the oesophagus passes gradually into a large, pear-shaped bulb, 0*18-0*22 mm. 

 in diameter, and containing a well-developed valvular apparatus. The nerve-ring is 

 situated at 03 mm., and the excretory pore at 0*45-0-5 mm., fiom the anterior end. 



In the male, the caudal end is provided with very broad alae. The tail proper 

 (i.e., the postanal portion) measures 0-45-0*5 mm. in length, and tapers beyond the 

 alae to a fine filament. The preanal sucker measures 0*08-0*09 mm - m diameter, and 

 is situated at 0*1-0*15 mm - from the cloaca. Both spicules are alate, the alae of the 

 short left spicule being very broad, those of the long right spicule much narrower. 

 The shorter spicule has a double bend near the tip. like that of H. papulosa, while the 



