Plectus parietinus
Bastian, 1865
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Female, length 1/23", breadth 1/400".
External Characters. Body white, tapering at either extremity. more especially posteriorly.  Head truncate, provided with a circle of four large rounded papillae.  Integumental striae transverse 1/18000" apart.
Pharyngeal cavity 1/643" long.  Oesophagus about 1/4 of total length.  Intestinal cells indistinctly tessellated, containing rather few light-coloured fat-particles.  Anus 1/250" from posterior extremity.  Vulva at middle of body.  Excretory ventral gland having twisted duct opening at 1/133" from anterior extremity.  Lateral vessels commencing at circular markings of integument 1/1250" from anterior extremity, by narrowed portions 1/1333" in length, with delicate vessels from 1/10000"  to 1/5000" broad.
Male not seen.
Hab. Hemispherical tufts of moss (Tortula) on the roofs of old houses or walls, and also from the yellow lichen (Parmelia parietina), Broadmoor, Berks.
(Description- Bastian, 1865)

L = 1.05-1.2 mm; a = 16-18; b = 4.5-4.7 ; c = 13-15; V = 47-49
(Bastian, 1865)    Female: L = 1.1 mm; a = 17; b = 4; c = 10.8
(Steiner, 1916)     Female: L = 1.29-1.54 mm; a = 18-25; b = 4.3-4.6; c = 10.9-14.9; V = 45-48
(Andrassy, 1958) Male: L = 1.1 mm; a = 21; b = 4.1; c = 12; spicules = 43 um
(Maggenti, 1961) Female: L = 0.93-1.7 mm; a = 12-25; b = 3.2-5.2; c = 8-15; V = 45-52
                            Male: L = 1.2-1.3 mm; a = 18-22; b = 4.3-4.8; c = 12-13; spicules = 60-64/44-56 um

    Body large and robust, ventrally arcuate.  Cuticle thick, especially on the neck, 3-4 um on mid-body region, distinctly annulated; annules 1.5-2 um wide on mid-body.  Lateral field 6-8 um wide, 1/7 - 1/8 of body width, with two alae.  Hypodermal glands large, 12-17 um, their number 44-58 on each side of body.
     Head well set off by  a constriction, 13-16 um wide, lips separate, conoid, 7-8 um high.  Cephalic setae short (4-5 um) but strong, directed forward.  Body on posterior end of oesophagus 3.4-4 times as wide as head.  Amphids 2.5-3.5 um wide, 12-16 um behind anterior extremity, level with mid-stoma.
    Stoma 24-26 um long, 1.8-2 times head diameter, 1/9 of oesophagus length, spacious.  Protostom 1/3 of stoma.  Oesophagus 225-250 um long, bulbus strong, cardial process short.  Excretory pore 121-137 um from head, in 53-55% of oesophagus length.  Rectum as long as anal diameter.
    Vagina 1/3 of corresponding body width, showing four muscle circles.  Each gonad 14-16% of body length.  Vulva-anus distance 5.9-6.6 times as long as tail.  Tail short and plump, 74-80 um, 2.4-3 times anal body diameter, 6.8-7.5% of body length.  Spur about one tail tip diameter from the extremity.  Further caudal setae three in number.
    The male was first described by Andrassy (1958) and then by Maggenti (1961).  It is characterized by the presence of five large tubular organs and a great number of short and thick setae on the posterior body end.  Spicules asymmetrical: either the right or the left one longer than the other.
(Description- Andrássy, 1985)


Measurements (from Mulk & Coomans, 1978)
L = 1.27-1.44 mm; a = 14.1-15.6; b = 4.4-4.5; c = 11.5-12.1; V = 46-47; stoma = 28-32 um

DNA Sequences Obtained
Specimen: Collected:
KonzaII AA-128 Konza Prairie, First Survey