Nematode Genus Tanqua, R. Blanchard. 227 



The spicules of the male are characterized by a peculiar 

 rasp-like covering of minute points or spinelets throughout 

 their length — a fact which the previous observers have 

 omitted to mention. 



In other respects the specimens which I assign to this 

 species agree well with von Linstow^s account (1904). A 

 table, showing in parallel series the measurements of certain 

 parts of the body in the various sets of specimens studied 

 and, for comparison, the measurements given by von Linstow, 

 will be found on p. 231. 



Fig. 3. 



Tanqua diadema. Head of an example from Helicops angulatus. 

 The right half is shown partly in optical section. 



C. G., cervical gland j Cu., fold of cuticle ; L., lip ; R.M., retractor 

 muscles of head. 



2. Tanqua diadema, sp. n. 



The following is an account of the second form, which, as 

 mentioned above, was discovered among the type-specimens 

 of Ascaris obconica, Baird, from the intestines of the South- 

 American fresh-water snake Helicops angulatus. 



The male measures about 20 mm. in length and 0*6 mm. 

 in thickness. The female is laraer, 28-30 mm. Ion": and 



