THE NEMATODE FAMILY GNATHOSTOMID^. 



269 



The bead-bulb (text-fig. 21) is divided into two hemispheres, 

 as in T. ano')nala. Tl:ie lips (text-fig. 21) are rather large 

 relatively to the head-bulb. The oesophagus occupies about 

 one-tenth of the total length. The cervical sacs are short. 



In the male the tail (PI. III. fig. 15; PI. IV. fig. 16) has 

 rather wide ahe. The caudal papillas are similar in number and 

 arrangement to those of the other species. The second pair from 

 the tip of the tail, however, are relatively small in some specimens, 

 and do not always show the basal swelling to a very marked 

 extent. The spicules are suddenly narrowed at the extremity to 

 form a little, conical, smooth tip (text-fig. 22). 



Text-figure 21. 



Text-fiffure 22. 



Li I 





Text-fig. 2\.—Tanqna diadema. The head, with the cuticular sheatli removed 



dorsal (or ventral) view. 

 Text-fig. 22. — Tanqua diadema. Terminal portion of spicule. 



Text-figure 23. 



0-5 mm. 



Tanqua diadema. Female genital organs. (Matm-e specimen.) 



In the female the tail is tapering and sharply pointed. The 

 vulva opens in the middle third of the body. The vagina (text- 

 fig. 23) is short and tliick. It opens at right angles into the 

 uterus, the two branches of which at once pass ofi" in opposite 

 directions, without further subdivision. 



