IX. vSTUDIES IN INDIAN HELMI NTHOL OG Y , 



No. I. 



By F. H. Stewart, M.A., D.Sc, M.B., CapL, I. M.S. 

 Hon. Asst.^ Indian Museum. 



(Plates xviii-xxiii). 



In the present report the following species are recorded,. 

 viz. : — 



1. Oxysoma macinioshii, n. sp. 



2. Oxysoma kachugae, n. sp. 



3. Heterakis macronis, n. sp. 



4. Dacnitis callichroi, n. sp. 



5. Spiroptera denticulata, R. var. minor ^ n. var. 



6. Atr.iciis kachugae, n. sp. 



7. Physaloptera, sp. larva. 



8. Ascaris, sp., larva (L. 33, 36). 

 9- „ ,, ,, (Iv. 15). 



10. Larva undiagnosed {L. 30). 

 II- ,, ,, (L. 14). 



12 Oncholaimus indicus, v. Ijnst. 



I. Oxysoma macintoshii, n. sp. 



(PI. xviii, figs. 1-12). 



From rectum of Rana tigrina, Daud., and Bufo 

 stomaticus, Liitken Lucknow. 



Plump little worms, the body cavity being more developed 

 and less closely packed with viscera than in many nematodes; 

 greater variations in shape and consequently in the measure- 

 ments occur — {vide tables I and la pp. 184, 185). The head can be 

 invaginated into the anterior part of the body, a fact which also 

 contributes to variations in the measurements. 



Females (fig. i) i'9-2 78 mm. long. Head (fig. 3). The mouth 

 is surrounded by three lips, one dorsal, two subventral. Each 

 lip is low, semicircular and membranous, the edge thickened 

 The lips curve in toward the mouth forming a diaphragm over 

 the shallow oral cavity. The base of this cavity is formed by the 

 anterior end of the oesophagus from which three powerful chitin- 

 covered teeth, one dorsal, two subventral, project into it. 



A curved chitinous flagellum can be observed in some speci- 

 mens, springing apparently from the apex of the dorsal tooth. 



The head can be retracted into the neck until the mouth is 

 at the level of the collar. 



