Adenoplea meridionalis Kolasa, 1981

(Fig. 1 B)

New localities. The “Lommelse Sahara”, Lommel, Belgium (51°14’48”N; 5°17’46”E), moss in a pine forest (23 July 2008)

Known distribution. Fosso Contesora, Italy, found on mosses on the banks of a helocrene spring (Kolasa, 1981).

Material. A horizontally-sectioned and three sagittally-sectioned specimens from Lommel (UH nrs. VI.4.09– VI.4.12).

Descriptive notes and remarks. The studied specimens have the same habitus and internal organization as Adenoplea meridionalis Kolasa, 1981, at least as far as could be judged from the description and drawings of Kolasa (1981). Animals about 1 mm long. Rostrally, two groups of adenal rhabdites are present. Protonephridiopores open in the mouth pouch. The rosulate pharynx lies just caudally from the body’s midpoint.

The gonopore (Fig. 1 B: gp) is situated at ±80 % of the body and opens into a genital atrium (Fig. 1 B: ga), which is lined with a high epithelium and is surrounded with muscles. Testes were not observed. The paired vasa deferentia (Fig. 1 B: vde) unite before entering the 35-µm-long copulatory organ. This organ contains an intracapsular seminal vesicle (Fig. 1 B: vs), a muscular, sclerotized ejaculatory duct (Fig. 1 B: de) and extracapsular (Fig. 1 B: gg1) as well as intracapsular (Fig. 1 B: gg2) basophilic prostate glands. It is entirely surrounded by two layers of strong spiral muscles (Fig. 1 B: mu). The thin-walled male duct is very short and is surrounded by a thin muscle layer. The copulatory bursa (Fig. 1 B: bu) opens directly in the genital atrium.

The vitellaria (Fig. 1 B: vi) extend from the middle of the body to the posterior end, where they fuse. Coarsegrained, eosinophilic female glands (Fig. 1 B: fg) open into the long female duct (Fig. 1 B: fd), which proximally receives the oviduct (Fig. 1 B: od), the seminal receptacle (Fig. 1 B: rs) and the unpaired vitelloduct.

Discussion. See the discussion following the descriptive notes and remarks on Adenoplea perigraptopera .

B

vde vi od ov vde

od

fd gp

bu

ga gg2

ph m vg md gp

de ga fd

C E ph

pp

vde

ov

gu vi

vg

gg2 D

ph gu