Arachnologische Mitteilungen 58

3D models of Porrhomma vulvae 3 of the fold goes directly towards the median plane in P. mi­ crops (Fig. 2c), whereas it goes obliquely in P. profundum (Fig. 2d).The whole main sacks are oriented to the sides in P. mi­ crops (Fig. 2c), whereas they are oriented obliquely upwards in P. profundum (Fig. 2d). In the 3D model, all differences are clearly visible. Models are freely available to view on: http://adamruzicka.cz/porrhomma/ Discussion A 3D model combines ventral, dorsal, lateral and caudal views and represents a good approach to understand the spatial structure of the vulva.The accuracy of the final reconstruction is not comparable to that using micro-computed-tomography and serial sectioning and visualization using 3D-reconstruc- tion software (e.g. Runge & Wirkner 2016). 3D modelling is not meant to provide a completely realistic image, rather to present morphological aspects in a more comprehensible way. References Kovblyuk MM, Kastrygina ZA & Marusik YM 2017 New data on Hahnia C.L.Koch,1841 fromCrimea (Aranei: Hahniidae).–Tur- kish Journal of Zoology 41: 311-317 – doi: 10.3906/zoo-1603-55 Miller F & Kratochvíl J 1940 Ein Beitrag zur Revision der mittel- europäischen Spinnenarten aus der Gattung Porrhomma E. Sim. – Zoologischer Anzeiger 130: 161-190 Qing X, Sánchez-Monge A & Bert W 2015 Three-dimensional modelling and printing as tools to enhance education and research in Nematology. – Nematology 17: 1245-1248 – doi: 10.1163/15685411-00002932 Runge J & Wirkner CS 2016 The hemolymph vascular system in Araneus diadematus with special focus on intraspecific variability in artery systems. – Journal of Arachnology 44: 153-164 – doi: 10.1636/JoA-S-16-001 Růžička V 2018 A review of the spider genus Porrhomma (Araneae, Linyphiidae). – Zootaxa 4481: 1-75 – doi: 10.11646/zoota- xa.4481.1.1 Thaler K 1968 ZumVorkommen von Porrhomma -Arten inTirol und anderen Alpenländern (Arachn.,Araneae,Linyphiidae).– Berichte des Naturwissenschaftlich-Medizinischen Vereins in Innsbruck 56: 361-388 Thaler K 1991 Porrhomma . In: Heimer S & Nentwig W (eds.) Spin- nen Mitteleuropas: ein Bestimmungsbuch. Paul Parey, Berlin & Hamburg. pp. 236-23