Potamon mutandensis Chace 1942: 194–197 Potamonautes mutandensis : Ng et al. 2008: 171 Potamonautes mutandensis P. mutandensis (Cumberlidge 2008b) The freshwater crabs of Lake Kivu (Crustacea: Decapoda: Brachyura: Potamonautidae) Cumberlidge, Neil Meyer, Kirstin S. Journal of Natural History 2011 2011-08-31 45 29 - 30 1835 1857 4M4JD (Chace, 1942) Chace 1942 [462,920,1247,1272] Malacostraca Potamonautidae Potamonautes Animalia Decapoda 7 1841 Arthropoda species mutandensis  ( Figures 3–5, Table 2)      Potamon mutandensis Chace 1942: 194–197, fig. 4, 5a–g.     Potamonautes mutandensis: Ng et al. 2008: 171; Cumberlidge et al. 2009: Appendix 1.   Material examined  Type material.  Uganda. Holotype: adult male (CW 25.7, CL 19.1, CH 9.5, FW 7.8), Mushongero, Lake Mutanda, Kigezi District, coll. A. Loveridge,  1 February 1939( MCZ11232).  Paratype: Mushongero, Lake Mutanda, Kigezi District, coll. A. Loveridge,  1 February 1939( MCZ11233); four adultmales (CWs 22.5, 20.8, 20.5, 19.6), two adultfemales (CWs 25.1, 21.3) Lake Bunyonyi, Kigezi District, from  outflowing stream  100 mfrom the lake in the outflow stream, coll. R. H. Lowe,  21 November 1952( NHM 2010.214– 219).  Other material.Democratic Republic of Congo. Adult male (CW 21.6, CL 15.0, CH7.4, FW 5.7) plus a number of incomplete specimens with detached legs, Lake Kivu,  12 December 1917, coll. Robin Kemp( NHM  1917.12.126–25).  Diagnosis Carapace narrow (CW /CL 1.3), medium height ( CH /FW 1.22); surface smooth; postfrontal crest faint to absent; epibranchial tooth absent; exorbital tooth low; cervical grooves faint, very long; third maxilliped with faint vertical groove ( Figure 3A,B); first carpal tooth low, blunt, followed by two or three granules; distal meral tooth distinct, pointed ( Figure 3A,C); sternal sulcus s2 /s3 deep, running horizontally across sternum; sulcus s3 /s4 incomplete, deep on sides but missing in middle ( Figure 3C); terminal article of GO1 turned strongly outward; distal margin of subterminal segment highest on medial side, forming pronounced shoulder, lowest on lateral side; margins of subterminal segment of GO1 with long setae ( Figure 4A–C).  Distribution   Lake Mutandaand Lake Bunyonyiin Uganda, and Lake Kivuin the Democratic Republic of Congo. The typelocality label reads Mushongero( 1 ◦10 ′43 S, 29 ◦40 ′58 E,  1888 masl), which is on the road close to the northeast shoreline of Lake Mutanda( Figure 5).  Conservation status    Potamonautes mutandensiswas assessed as Endangered (EN) using the IUCN Red List criteria ( IUCN 2003; Cumberlidge et al. 2009, appendix) because of its limited range and vulnerability to invasive crayfish. However, the present study shows that this species is more widespread than previously thought, and that this species occurs over a wide range ( Figure 5). The conservation status of  P. mutandensis(Cumberlidge 2008b)therefore needs to be reassessed in the light of the new records presented here.   Remarks This revised diagnosis is intended to update the original description of this species by Chace (1942). Bott (1955)considered  P. mutandensisto be a junior synonym of  P. emini(Hilgendorf, 1892)from Tanzania. Reed and Cumberlidge (2006)provided a redescription of  P. emini, plus photographs, illustrations and a distribution map of the species.  Potamonautes mutandensiscan be distinguished from  P. eminiby the following characters: the dactylus of the major cheliped of  P. mutandensisis highly arched, whereas that of  P. eminiis only slightly arched; the superior margin of the carpus of the cheliped of  P. mutandensishas only faint carinae, whereas these carinae are strong in  P. emini; episternal sulci s4 /e4, s5 /e5, s6 /e6, s7 /e7 are incomplete but still visible in  P. mutandensisbut absent and smooth in  P. emini; the distal margin of the subterminal segment of GO1 at the dorsal membrane is diagonal in  P. mutandensisbut U-shaped in  P. emini; and the medial and lateral margins of the dorsal membrane of GO1 are of subequal width in  P. mutandensis, whereas the lateral margin is longer than the medial margin in  P. emini; finally, the medial and lateral folds of the terminal article of GO1 are even in  P. mutandensis, whereas the lateral fold is higher than the medial fold in  P. emini. MCZ 11232 1939-02-01 MCZ Mushongero & A. Loveridge Uganda Lake Mutanda Kigezi District 7 1841 1 holotype MCZ 11233 1939-02-01 MCZ Mushongero & A. Loveridge Uganda Kigezi District Lake Mutanda Lake Bunyonyi 7 1841 2 2 paratype 1952-11-21 R H. Lowe 100 8 1842 NHM 2010.214, 219 1 1917-12-12 NHM Robin Kemp CH Lake Kivu 8 1842 1 Uganda Lake Mutanda 1888 -1.178611 Lake 21 29.682777 Lake Bunyonyi 8 1842 1 Sud-Kivu