Johannes Fibiger and Hjalmar Ditlevsen: Spiroptera neoplastica n. sp. 19 



of 165 fi from the tip of the tail, — which — considering the small size of the male 

 — will be relatively a great deal more than in the female. 



The tail of the male has the shape of a cork-screw as is generally the case in 

 all the species belonging to the genus in question. The windings are distinct although 

 not so marked as may sometimes be observed. The bursa has a rather considerable 

 size. In a male of average size (c. V^h ctm.) the bursa has a length of 462 n and a 

 maximal width of 170^, measured from one edge to the other. Its shape is asymet- 

 rical which is no uncommon faet in these nematodes; this, however, not only ap- 

 plies to the exterior shape of the bursa, it also may affect the placing and relative 

 size of the papillæ on both sides, as well as the mutual size and shape of the spicules. 

 Even Schneider describes this. ^) 



"Bursa und Papillen sind bei einer grossen Zahl von Species asymmetrisch gebildet 

 und gesteilt. Die eine Seite der Bursa ist långer und breiter, zugleich riicken die auf 

 derselben stehenden Papillen weiter nach vorne und aus einander. Die Spicula sind 

 immer ungleich und bei den verschiedenen Species von sehr verschiedener Ge- 

 stalt." — 



In the species concerned one side of the bursa very distinctly appears to be nearly 

 ^/s shorter than the other side, the measure mentioned (462 fj) thus applies to the 

 longer one. The bursa, on the wliole, has a longish oval shape with a distinct con- 

 striction on the middle, somewhat more pronounced on the longer side and placed 

 more caudally on the shorter side. The lower convexity is somewhat more distinct 

 on the longer side. Towards the tip of the tail the bursa narrows very consider- 

 ably, the side edges approaching each other. Almost in front of the hindmost set of 

 papillæ a small dilatation is observed after which the lips converge to a small rounded 

 lingulate tip, reaching c. 14 n outside the tip of the tail. 



Besides the 4 preanal papillæ constantly present in the genus of Spiroptera 4 post- 

 anal papillæ are found on each side. They are all equally shaped, most slender on their 

 point of fixation to the bursa, and evenly increasing in width; the outermost part form- 

 ing a headshaped or rather discoidal dilatation. The 4 preanal papillæ almost have the 

 same size; they are bigger than the postanal papillæ and measure c. 20// in length. 

 Among the postanal papillæ the set next to the anogenital duet is the largest, after 

 which they gradually decrease in size, rendering those proximate to the tip of the tail 

 only c. 10 // in length. 



As already mentioned a distinct asymmetry is to be noted in regard to their 

 placing; all the row of papillæ on the longer side of the bursa has been drawn some- 

 what more cephalic than those of the shorter side. It is, however, the question only 



') Anton Schneider: Monographie der Nematoden p. 84. 



3* 



