1914.] F. H. Stewart : Indtan HeliiiiiUhology, No. I. 167 



Thus the characteristic three preanal ® and three perianal papillae 

 of the genus Oxysoma are found. 



The tail is sharp pointed but relatively stouter than in the 

 female. Postanal papillae (fig. 6) occur, seven pairs on the 

 ventral half of the tail and six pairs on the dorsal half. 



The spicules (figs. 8, 9, ii, 12) two in number, are long, 

 measuring each 1 of the body length. They are stout hollow 

 cylindrical structures, '013 mm. in thickness. In one specimen 

 the wall of the cylinder is so thick that vacuoles can be observed 

 in it. Two muscular bands are attached to the anterior end of 

 each spicule. 



The gonads appear to consist of a single tube divided into 

 an upper testicular region, a large seminal vesicle and a short 

 vas deferens. 



The species is named in honour of my teacher and friend 

 Professor Macintosh of St. Andrews. 



Comparison of this species with species described by Dujardin (3). 



{A.) Heterakis acuminata, Schrank. The Lucknow speci- 

 mens differ from Heterakis acuminata, Schrank, as described by 



Dujardin, in that the males possess long spicules ( ^'^^^^ = ^) 

 not short spicules. 



(Z?.) Heterakis brevicaudata, Duj. They agree with the 

 Heterakis brevicaudata of Dujardin in characters of generic value, 

 namely: (i) as regards the head, '' tete obtuse, a trois lobes peu 

 distincts, non mucrones, separes a I'interieur par des pieces 

 cornees ". " Pharynx long de -05. mm. a trois angles— et separe 

 de I'oesophage par une sorte de diaphragme armee de trois pointes 

 horizontales ' ' may be the same structure as the anterior portion 

 of the oesophagus described above. A specimen of Oxysoma sp. ? 

 from the rectum of an English specimen of Rana temporaria 

 (kindly given to me by my friend Dr. Dobell) exhibits the struc- 

 ture of the head identical with that of the lyucknow specimens. 

 Dujardin's specimens were obtained in Paris and Rennes; (ii) as 

 regards the tail of the male — ''Male a queue, .munie de deux 

 membranes tresetroites et de deux rangees de. .papilles. .• deux 

 spicules tres-longs. 



They however differ from this species in many characters. 

 (1) Size— females not longer than 278 mm., whereas H. brevicaudata, 



Duj., measures 4' 5-6 mm. The relation >j'j^ " equals - as con- 

 trasted with — in H. brevicaudata. (ii) The vulva is in front of 

 the middle, in H. brevicaudata it is behind the middle, (iii) 



Postanal length . , i . , t t 



tX. ^^ ^ equals g : m & equals -, contrasted with ~ 



in both sexes in H. brevicaudata, (iv) Papillae of tail ina' 6 pairs 

 contrasted with 13 in H. brevicaudata. (v) Spicules strong, stout 



