A revision of the genus Cheliplana de Beauchamp, 1927 (Rhabdocoela: Schizorhynchia), with the description of six new species Author Gobert, Stefan 0000-0003-1949-9174 Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. & stefan. gobert @ uhasselt. be; https: // orcid. org / 0000 - 0003 - 1949 - 9174 stefan.gobert@uhasselt.be Author Diez, Yander L. 0000-0001-8741-4799 Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. & University of Oriente, Departement of Biology and Geography, Avenida Patricio Lumumba s / n, CP 90500, Santiago de Cuba, Cuba. Beaty Biodiversity Research Centre, Departments of Botany and Zoology, University of British Columbia, 3529 - 6270 University Blvd, Vancouver, BC, V 6 T 1 Z 4 Canada. & yander @ uo. edu. cu; https: // orcid. org / 0000 - 0001 - 8741 - 4799 yander@uo.edu.cu Author Monnens, Marlies 0000-0002-9133-1512 Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. & marlies. monnens @ uhasselt. be; https: // orcid. org / 0000 - 0002 - 9133 - 1512 marlies.monnens@uhasselt.be Author Reygel, Patrick 0000-0001-8721-6290 Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. & patrick. reygel @ uhasselt. be; https: // orcid. org / 0000 - 0001 - 8721 - 6290 patrick.reygel@uhasselt.be Author Van Steenkiste, Niels W. L. 0000-0002-2676-7862 niels. vansteenkiste @ botany. ubc. ca; https: // orcid. org / 0000 - 0002 - 2676 - 7862 niels.vansteenkiste@botany.ubc.ca Author Leander, Brian S. 0000-0003-0798-0470 bleander @ mail. ubc. ca; https: // orcid. org / 0000 - 0003 - 0798 - 0470 bleander@mail.ubc.ca Author Artois, Tom Hasselt University, Centre for Environmental Sciences, Research Group Zoology: Biodiversity and Toxicology, Universitaire Campus Gebouw D, B- 3590 Diepenbeek, Belgium. text Zootaxa 2021 2021-05-17 4970 3 453 494 journal article 6258 10.11646/zootaxa.4970.3.2 281c9017-f55b-47bf-bea0-e511a7173605 1175-5326 4766692 FEABE248-E1EA-48F5-A1AF-0077FE40C257 Cheliplana setosa Evdonin, 1971 Fig. 9A–D Material examined. New material. CANADA • 1 whole mount; British Columbia , Calvert Island , Foggy Cove ; 51°39’07”N , 128°08’32”W ; 9 Apr. 2016 ; medium-grained sand in between boulders in the lower intertidal; MI4193 • 1 whole mount; British Columbia , Bamfield, Brady Beach; 48°49’40”N , 125°09’12”W ; 3 Jun. 2015 ; mediumgrained sand in lower intertidal; MI4194 . Reference material. 1 whole-mounted specimen ( SMNH 90403) and 1 serially sectioned specimen ( SMNH 102990) from California , United States . FIGURE 9 . A–D. Cheliplana setosa Evdonin, 1971 from British Columbia, Canada. A. Live specimen. B. Detail of the male copulatory organs in a live specimen. C. Detail of the proboscis with proboscis hooks and hook supports in a wholemounted specimen. D. Detail of the male copulatory bulb with prostate vesicle and tripartite cirrus in a whole-mounted specimen. E. Cheliplana californica Karling, 1989 from British Columbia, Canada. Detail of the male copulatory bulb with cirrus in the whole-mounted specimen. Scale bars: A = 100 μm; B = 20 μm; C = 10 μm; D–E = 20 μm. Known distribution . Posyet, Peter the Great Gulf, Russia ( Evdonin 1977 ). Monterey Bay, California , United States ( Karling 1983 ). Ría de Villaviciosa, near San Martin, Spain ( Noreña et al. 2007 ). Remarks . Live specimens are ~ 1.5 mm long. Specimens are yellowish to pinkish in colour ( Fig. 9A ). The proboscis bears curved proboscis hooks measuring 18–20 μm (h, Fig. 9C ). Hook supports are about 12 μm long in the specimens from Canada (hs, Fig. 9C ). Rod-shaped, weakly sclerotised proboscis sidepieces were observed by Karling (1983) . The prepharyngeal tube is armed with spines (ppc, Fig. 9A ). A single, large testis is situated alongside the pharynx (ph, t, Fig. 9A ). Karling (1983) reports a lobe containing sperm at the posterior end of the testis. A pair of seminal vesicles, one of which ending blindly, the other connecting to the testis via an unpaired vas deferens, enter the proximal end of the copulatory bulb (cb, vs, Fig. 9A–B,D ). The copulatory bulb is oviform (cb, Fig. 9A–B,D ). In the Russian specimens, Evdonin (1971) measures a size range of 110 to 120 μm for the copulatory bulb. The Californian specimen described by Karling (1983) possesses a copulatory bulb of ~130 μm. The copulatory bulbs in the new specimens from Canada are somewhat larger still, measuring 130–160 μm. The copulatory bulb holds a cirrus of 40–60 μm ( Russia and California) ( Evdonin 1971 ; Karling 1983 ) or 68–85 μm ( Canada ) (ci, Fig. 9 A–B,D ). The cirrus can be divided in three clearly defined regions: (1) a proximal tube-like region of ~48 μm (California) to 48–60 μm ( Canada ), armed with fine spines, (2) a ring of five or six large spines of about 10–15 μm ( Canada ) long, set in sclerotised pockets, and (3) a distal region of ~7 μm (California) to 15–17 μm ( Canada ) long, wider than the proximal region, armed with hair-like spines. A single ovary (ov, Fig. 9A ) and bursa are situated near the caudal body end.