Limnoterrestrial ‘ Typhloplanidae’ (Rhabdocoela, Platyhelminthes), with the description of four new species and a new genus Author Houben, Albrecht M. 47A2BBE9-0820-4E83-B8BD-B41A66C214ED Biodiversity & Toxicology, Agoralaan Gebouw D, B- 3590 Diepenbeek, Belgium. albrecht.houben@gmail.com Author Monnens, Marlies 782F71E0-EF84-48DA-BE72-8E205CB78EAC Biodiversity & Toxicology, Agoralaan Gebouw D, B- 3590 Diepenbeek, Belgium. marlies.monnens@uhasselt.be Author Proesmans, Willem 41B81434-06EE-4BD0-8DCE-4DE73F2A6B30 Agroécologie, INRAE, 17 Rue Sully, F- 21065 Dijon, France. willem.proesmans@gmail.com Author Artois, Tom J. 2EDDE35C-A2F0-4CA2-84AA-2A7893C40AC4 Biodiversity & Toxicology, Agoralaan Gebouw D, B- 3590 Diepenbeek, Belgium. tom.artois@uhasselt.be text European Journal of Taxonomy 2022 2022-03-01 798 70 102 http://dx.doi.org/10.5852/ejt.2022.798.1671 journal article 20416 10.5852/ejt.2022.798.1671 dc185c1a-2bc2-48f1-bbdd-e0ae42f852f1 2118-9773 6323040 F136E044-62C8-4FB3-8160-7DAE663D9600 Krumbachia subterranea Reisinger, 1933 Fig. 8A–C Material examined Neotype GERMANY • 1 spec. , studied alive and sagittally sectioned; Hessen ; 50°46′30″ N , 09°30′18″ E ; 9 Aug. 2011 ; A.M. Houben and W. Proesmans leg.; submersed meadow at the banks of the Breitenbach creek ; neotype no. 823 ; HU . Reference material GERMANY • 1 spec. , live observations; same collection data as for neotype . Description The examined specimens are around 2.5 mm long. The body is slender with a somewhat pointy anterior end and rounded posteriorly (see Fig. 8A ). Adenal rhabdite glands occur just behind the brain ( Fig. 8A : ar). Paired protonephridiopores (pp) are positioned ventrally, very near to the mouth ( Fig. 8A : pp). A rosulate pharynx ( Fig. 8A : ph) is situated just behind the centre of the body. The gonopore ( Fig. 8A–C : gp) is located at ±75% of the body and connected to the gonoduct ( Fig. 8B– C : gd). The gonoduct is surrounded by an inner circular and outer longitudinal muscle layer, and lined with a ciliated, nuclear epithelium resembling the epidermis. The genital atrium ( Fig. 8A–C : ga) is surrounded by a similar musculature and lined with a high, nucleated epithelium. On both lateral sides of the genital atrium, a group of proliferating cells ( Fig. 8C : pc) is found. A large group of eosinophilic glands is situated posterior to the genital atrium and probably enters this atrium anteriorly (not drawn on the reconstruction). The large, egg-shaped testes ( Fig. 8A : t) lie anterior to the pharynx and ventral to the vitellaria ( Fig. 8A– B : vi). Paired vasa deferentia unite to form a single vas deferens ( Fig. 8A–C : vde) just before entering the copulatory bulbus ( Fig. 8A : co). Two layers of spiral muscles surround the long, curved copulatory organ, which bends up to 80° towards its distal end. The copulatory organ bears an intracapsular seminal vesicle ( Fig. 8B–C : vs) and a strongly sclerotised ejaculatory duct ( Fig. 8B–C : de). Several coarsegrained, extracapsular eosinophilic glands ( Fig. 8A–C : gg) enter the copulatory organ at the proximal end. Their secretion is lightly basophilic when entering the copulatory organ, however, it becomes strongly eosinophilic in the ejaculatory duct. A cone-shaped bursa ( Fig. 8A–C : bu), surrounded by strong inner circular and outer longitudinal muscles, lies next to the copulatory organ and opens into the genital atrium. The vitellaria extend from the region of the rhabdite glands to the posterior end ( Fig. 8A : vi). The vitelloducts ( Fig. 8C : vd) fuse just before opening into the female duct ( Fig. 8C : fd). Furthermore, this duct is surrounded by a layer of circular muscles and receives the oviduct, a seminal receptacle ( Fig. 8A–C : rs), and the female glands ( Fig. 8C : fg). The seminal receptacle is provided with a short stalk, which also is surrounded by circular muscles. Discussion See the general discussion on the genus Krumbachia Reisinger, 1924 . Fig. 8. Two species of Krumbachia Reisinger, 1924 . A–C . Krumbachia subterranea Reisinger, 1933 . A . Internal organisation of a live specimen. B . Organisation of the genital system of a live specimen. C . Reconstruction of reproductive organs based on sagittal sections of the neotype (neotype no. 823). D–E . Krumbachia virginiana ( Kepner & Carter, 1931 ) Ruebush, 1938 . D . Internal organisation of a live specimen. E . Reconstruction of reproductive organs based on sagittal sections. Previously known distribution Ruhr, Germany ( Reisinger 1933 ), riparian forest near Schlitz, Germany ( Schwank 1981 ). Common species in Europe ( Lanfranchi & Papi 1978 ).