552 DISCOVERY REPORTS 



relatively coarse in the oesophageal region, where they have prominent posterior edges, 

 giving the outlines of the body a saw-like appearance in optical section. The interval 

 betw^een the striations in this region is about o-oi mm. in the male and 0-015 mm. in 

 the female. More posteriorly the striations are much finer and less prominent. The 

 cuticular spines which are so conspicuous a feature in other species of the genus, 

 forming complete circles on the posterior edges of the cuticular rings, are here repre- 

 sented by very small spines confined to the ventral surface of part of the oesophageal 



0-2 MM. ^ 



Fig. 9. Spinitectus guntheri. Part of the female genital organs, in 

 lateral view. (The arrow points towards the anterior end.) u^, «-, 

 the two uterine branches; v., vulva; vag., vagina. 



region. They do not extend forward much beyond the level of the junction of the two 



portions of the oesophagus, or backw-ard as far as its posterior end. 



The paired lateral lips are conical, and each appears to be provided with three 

 papillae, one near the apex and two at the base. The lateral walls of the buccal capsule 

 are formed by a continuation of the thickened cuticle of the lips, while its dorsal and 

 ventral walls begin at the level of their bases. There is a pair of prominent cervical 

 papillae, situated, in the female, at about 0-17 mm. from the anterior extremity. The 

 nerve-ring is situated at about o-2-o-2i mm., and the excretory pore at about 0-25- 

 0-29 mm., from the anterior end. 



The posterior end of the male is spirally coiled. The tail is about 0-23 mm. long, and 

 is conical. There are slight lateral alae, into which project ten pairs of preanal and five 

 pairs of postanal papillae. The cuticle of the ventral surface, for some distance from the 

 posterior end, is raised into numerous longitudinal series of rectangular plates or tuber- 

 cles. These doubtless correspond to the more restricted number of rows of "plates", 

 "tubercles" or "ridges" described in other species (four rows in S. cristotiis Railliet 

 and Henry, 1915 (= Filaria serrata Linton, 1901) and S. ranae Morishita, 1926; 

 four to eight rows in S. gracilis Ward and Magath, 19 16). The left spicule is long and 

 filiform, measuring about 2-5 mm. in length. The right spicule is very stout and measures 

 only about 0-25 mm. in length. There is no accessory piece. 



In the female, the tail, which is rapidly tapering and pointed, is 0-23-0-27 mm. long. 

 The vulva is situated at 6-2-6-7 mm. from the posterior end. The vagina runs forward 

 at first from the vulva, but soon doubles back again, and at about the level of the vulva 

 expands into a small oval swelling, which gives off at right angles to itself the two uterine 



