Rhabditis aspera Btitschli. (Fig. 11.)

B ü tschli, 1873, pp. 113-114, pl. ix, fig. 58 a-e.

Dimensions.- ♂. Body-length= 0.760 mm., max. width = 0.036 mm., o esophagus = 0.188 mm., tail= 0.0 3 3 mm, α=21.11, β= 4.04, γ=-23.03. ♂. Body - l e n g t h =l.0 mm., max. width =0.0 5 1 mm., o esophagus=0.220 ram., tail=0.0 2 6 mm., α=2 0.0, β =4.55, y =38.46. ♀. Body -length = 0.885 mm., m a x. width = 0.038 mm., o esophagus= 0.180 mm., tail = 0.0 3 3 mm., v u l v a=0.5 5 7 ram., α=2 3.2 9, β=4.92, γ=2 6. 8 2, V =6 2. 9 3 per cent. ♀. Body -length =l. 0 1 8 mm., max. widths= 0.026 mm.,

o esophagus = 0.220 mm., vulva: 0.6 0 5 mm., α =3 9.1 5, γ= 4.63, V = 5 9. 4 3 per cent.

The body is moderately slender, on the whole o f even thickness, it tapers imperceptibly in a posterior direction a n d only gradually in the foremost part of the o esophageal region,

Cuticle smooth. Head rounded, w i t h clearly developed lips. Buccal

c a v i t y short and broad. L e n g t h 16.39/z a n d thickness 4.9/z. The oesophagus is thin, in the middle slightly swollen, posteriorly with a moderately large bulb. The tail is conical, narrower behind, sharply pointed. Vulva situated behind the middle o f the body. Female g o n a d thin,

extended posteriorly. Spicules typical. I n front o f the anus the bursa shows three pairs of ribs and behind the anus at the middle of the bursa t w o (3), more posteriorly one or t w o pairs o f ribs.