Arachnologische Mitteilungen 58

2 V. Růžička & A. Růžička ved around the appendices, and the axes of their end part are divergent; i.e. they are directed oblique laterally (Fig. 1b). In the 3D model, all these differences are clearly visible. Porrhomma microps (Roewer, 1931) versus Porrhomma profundum Dahl, 1939 In these two microphthalmic species, the copulatory ducts have a broad side loop and ascending part, and the sperma- thecae are situated deeper in the opisthosoma. All species of the microphthalmum -group are characterised by a conspicuous fold, which is formed in the uppermost part of the vulva (Růžička 2018). Vulvae are hardly distinguishable in ventral and dorsal views (e.g., Miller & Kratochvíl 1940). The main difference is visible in caudal view. The fold is very conspicuous in P. microps (Fig. 2a), but it is not as tight in P. profundum (Fig. 2b). Moreover, the inner branch Fig. 1: A model of the caudal (a,b) and dorsal (c,d) views of the vulvae. a, c. Porrhomma egeria ; b, d. Porrhomma campbelli . Abbreviations: A, appendix; MS, main sack; SL, side loop; axes of the end part of the main sacks Fig. 2: A model of the caudal (a, b) and dorsal (c, d) views of vulvae. a, c. Porrhommamicrops ; b, d. Porrhomma profundum . Abbreviations as in Fig. 1. F, fold of the copulatory duct; axes of the end part of the main sacks; a course of the inner part of the fold