264 



MR. H. A. BAYLIS AND LT.-COL. CLAYTON LANE ON 



anterior end to form two parallel branches which also run 

 forward. 



At the opposite extreme we have observed cases (text-fig. 14) 

 where the vagina runs into a moi'e or less oblong, swollen 

 uterine sac, which gives off a single branch at its posterior end 

 and three branches side by side anteriorly. Between these 

 extremes of variation there appear to be intermediate forms 

 (text-fig. 15) in which the point of origin of the first of the three 

 anteiior branches shows a greater or less tendency to approach 

 that of the other two. The shape of the common uterine 

 chamber varies considerablv. We are unable to recognize in 



Text-figure 15. 



It. ^■^■ 



ut. va. 



Tanqua tiara. Female genital organs. (Young specimen from Nigeria.) 



these varieties in the form of the female organs any of systematic 

 value, since we have found the same range of A^ariation in 

 material from both Indian and African sources, and since the 

 extremes are, as has been stated, connected by intermediate 

 forms. 



Specific Diagnosis. 



Tanqua tiara (v. Linst.). 



Head-bulb divided in the adult into four swellings, each con- 

 taining a single ballonet. Head not retractile within the 

 cnticular collar. Vulva within the last quarter of the bodj^. 

 Uterus with three anterior branches and one posterior. 



Habitat : stomach of sexni-aquatic lizards (Varanida^). 



For list of hosts, see p. 271. 



2. Tanqua anomala * (v. Linst., 1904). (Text-figs. 16-20; 

 PI. IV. fig. 14.) 



Heterakis anomala v. Linstow (1904 a, p. 97 ; pi. i. figs. 



10-11). 

 Tanqua anomala Baylis (1916, p. 229). 

 T. tiara (in part) Baylis (1916, p. 223 ; text-fig. 2). 



Of this species we have now, through the kindness of Dr. 

 J. Pearson, of the Colombo Museum, had the opportunity of 



* For specific diagnosis, see p. 268. 



