Oxyuris paronai, v. Linst. 



125 



protruded in only a small proportion of the specimens. It 

 then has the appearance represented in fig. 2, when seen 

 under a high magnification ( T V oil-immersion objective). 

 In the majority of the specimens" the "funnel" is withdrawn 

 into the anterior end of the oesophagus. This arrangement 

 somewhat resembles the structure seen in Crossocephalus. In 

 that genus, however, the funnel-like apparatus supported by 

 the six jaws is inverted into the oesophagus when closed. In 

 P. paronai, as far as can be made out, it is probably simply 

 retracted, without inversion. 



The " pigmentation ** of the oesophagus, intestine, and other 

 parts of 0. paronai, referred to by von Linstow, seems to 



Fig. 2. 



0-05 mm. 



Anterior extremity of Paracis paronai, highly magnified. 



have been due to some artificial discoloration. It is not seen 

 in the material collected by Mr. Loveridge. 



As, at present, generic distinctions among the Oxyurida? 

 rest almost entirely upon male characters, it is proposed to call 

 the new form, as distinct from P. paronai, Oxyuris Joveridgei, 

 sp. n., using the name Oxyuris in a broad sense. Further data 

 may show that it is really a dimorphic form of P. paronai, but 

 the chief reasons for regarding it for the present as a distinct 

 species are: (1) the different proportional length of the 

 oesophagus; (2) the different structure of the mouth, which 

 appears to be quite simple and without the funnel-like 

 apparatus, but merely surrounded by three small sessile 

 papillae ; (3) the position of the vulva, which is in front of 



