NEMATODE GEHUS PHYSALOPTEBA. 1067 



After a study and comparison of these three species, I hold that, 

 although they are nearly related, they must be regarded as distinct 

 species. Ph. varani differs from Ph. paradoxa by its longer 

 oesophagus, longer trunlf, mode of origin of the four uteri, and 

 the absence of a denticular ridge on the inner side of each lip. 

 It differs from Ph. quadrovavia by its longer oesophagus, shorter 

 tail of the female, less evolved type of origin of the uteri, and 

 also by the absence of denticles on the inner surface of the 

 lips. 



Ph. varani appears to be very closely related to Ph. abbreviata, 

 as redescribed by Seurat (1914 Z) and 1917 a), with which species 

 it agrees in the female genitalia. It appeal's, however, to differ 

 from Ph. ahbi-evicijta in its larger size, absence of denticles on the 

 inner surface of the lips, relatively shorter bursa, and larger 

 spicules. I have unfortunately not been able to examine and 

 compare any examples of Ph. abbreviata. 



Ph. 2^'^Mariii Seurat, 1917, seems to be a near relative of 

 Ph. varani, from which species it can, however, be very easily 

 distinguished by its much shorter left spicule, the conformation 

 of the circumcloacal area, and by the position of the vulva in 

 front of the posterior limit of the oesophagus. 



Parona's (1889) description differs from my findings in that 

 he mentions and figures the presence of four pairs of post-anal 

 ventral papillse, the last three pairs of which are equidistant 

 from each other, the 1st pair being situated immediately behind 

 the anus. I think an error has crept in his observations : namely, 

 that he has missed one pair of small papillae just behind the 1st, 

 and has misjudged the distance separating the 2nd and 3rd 

 pairs in his figure. I am led to this view because I think his 

 specimens could not have been well preserved, as he shows the 

 caudal alse having a lobulated border, a state of affairs which 

 I have noticed to take place in contracted specimens. I do not 

 think there can be any doubt as to the identity of the materials, 

 although Parona's description is so incomplete that it can apply 

 to quite a number of Physaloptera. 



(25) Physaloptera Antarctica v. Linstow, 1899. (Text-figs. 

 36 & 37.) 



Syn. Ph. alba Stoss., 1902. 



Fer)%ale. 



Mature and fully-grown females are abovit 45 mm. long and 

 950 [x broad. The body is of more or less uniform thickness, 

 only tapering slightly towards the anterior end. The body is 

 terminated by a short tail about 440 /x long. The cuticle is 

 roughly ringed, and between these rings a very fine cuticular 

 striati©n is observed under high-power magnification ; the cuticle 

 anteriorly is partly drawn over the lips. The cervical papillae are 

 lodged in shallow pits in the cuticle, and are situated about 650 ju, 



