14 



F.R. WANLESS AND R. HUNTER 



Fig. 18 Tylenchus rex Andrassy. 1979. A-F, male. A. anterior region: B, 

 oesophageal region; C, head region showing amphid; D. lateral field; E, 

 tail and spicular region; G. spicular region. Scale bars a = 20 jam, b = 50 

 |jm, c = 10 |jm, d = 100 urn. 



rather than smooth; the tail is longer ( 160 um vs 130-140 urn); ratio 

 c is lower (6.1 vs 6.3-6.6) whereas c' is slightly higher (9.0 vs 7-8). 

 However, these ratios and tail length fall within the range of meas- 

 urements given for T. rex by Brzeski (1996). 



Tylenchinae sp. 



(Figs 19, 36C) 



Material examined. Foyers Plateau: 159 m; core 14; 1 9. River 

 Foyers: 0.39 m; core 42, 1 9. 



Horizon. Core 14, (1-2 cm). 



Females, (n = 2). L = 468, 520 urn; a = 43.3, 40.6; b = 4.5, 4.7; c 

 = 4.7, 5.0; c'= 12, 12.5; V = 65, 62; V = 80; tail/V-a = 74.8, 94; tail 

 = 99.2, 104 um. 



Head not set off, about 6.6 um wide at base. Amphid apertures not 

 seen. Annules fine about 0.8 um at mid-body. Lateral fields narrow 

 with two lines. Spear moderately robust, 1 1 .5 um long with rounded 

 basal knobs 2.5 um wide; shaft slightly longer than conus. Oesopha- 

 gus 103, 110 um long; median bulb ovate, valve at about 45% of 

 oesophageal length. Excretory pore 71.4, 78.7 um from anterior. 

 Anterior genital branch 115, 109 um long. Spermatheca empty. 

 Postuterine sac not seen, possibly collapsed. Vagina about 6.0 um 

 long, slightly inclined or curved anteriorly. Tail elongate, not fili- 

 form; tip rounded. 



Remarks. The generic position of these nematodes is uncertain. 

 They are placed in Tylenchinae because they are close to Tylenchus 



Fig. 19 Tylenchinae sp. A-E. female. A. oesophageal region; B. tail: C. 

 lateral field: D. vulval region; E, habitus. Scale bars a = 10 um, b = 100 

 Um. 



Bastian, 1865 in which the anterior conus and posterior shaft of the 

 spear are about equal in length. However, the presence of two lines 

 in the lateral fields is not compatible with the generic definition of 

 Tylenchus, which is characterized by the presence of four lines 

 Additional material and SEM studies are required in order to resolve 

 the status of these interesting nematodes. 



Ditylenchus sp. 



(Fig. 20) 



Material examined. River Foyers; 0.39 m; core 44, 1 6. 



Male, (n = 1). L = 754 um; a = 58.9; b = 5.7; c = 7.4; c = 9.5; 

 spicule = 16 um; gubernaculum = 5.2 um; tail = 102 um. 



Head 4.2 um wide, annuli not seen. Cephalic framework weak. 

 Lateral fields with five lines at mid-body, apparently four lines on 

 anterior and posterior regions, but for the most part difficult to 

 observe. Body annuli fine, less than 1 .0 um wide. Spear delicate, 7.6 

 um long; cone shorter than shaft; knobs rounded about 2.0 um wide. 

 Excretory pore 91 um from anterior. Oesophagus 131 um long; 

 median bulb oval with distinct valve at 39.6% of oesophageal 

 length; basal bulb and isthmus indistinct. Caudal alae about 30.7 um 

 long, 30% of tail length. Tail terminus finely rounded. 



Remarks. Ditylenchus species are rather uniform and do not 

 show many characters helpful for identification (Brzeski, 1991b). 

 This single male cannot be named with any confidence and addi- 

 tional specimens, particularly females, are required for proper 

 identification. 



