Juga nigrina
Creators: name: Strong, Ellen E.
name: Garner, Jeffrey T.
name: Johnson, Paul D.
name: Whelan, Nathan V.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Architaenioglossa
Semisulcospiridae
Juga
Juga nigrina

description: Juga nigrina (I. Lea, 1856)
Figs 22–24
Melania nigrina I. Lea, 1856: 80.
Melania shastaensis I. Lea, 1856: 80. Syn. nov.
Goniobasis circumlineata Tryon, 1865: 244–245, pl. 24 figs 14–15.
Melania californica Clessin, 1882: 189–190, pl. 4 fig. 8 [sic, fig. 9]. No type material located. “ California ”.
Goniobasis chacei Henderson, 1935a: 132–134, pl. 4 fig. 8. Syn. nov.
Goniobasis coquillensis Henderson, 1935a: 131–132, pl. 4 fig. 6. Syn. nov.
Goniobasis orickensis Henderson, 1935a: 130–131, pl. 4 fig. 10. Syn. nov.
Goniobasis yrekaensis Henderson, 1935a: 97–98, pl. 4 figs 3–4. Syn. nov.
Goniobasis yrekaensis obscura Henderson, 1935a: 98–99. Syn. nov.
Goniobasis nigrina – Lea 1863a: 302, pl. 37 fig. 137; 1863b: 124, pl. 37 fig. 137.
Goniobasis shastaensis – Lea 1863a: 337, pl. 38 fig. 199; 1863b: 159, pl. 38 fig. 199.
Goniobasis circumlineata – Tryon 1866: 36, figs 237–238.
Goniobasis chacei – Henderson 1936b: pl. 2 fig. 8.
Goniobasis coquillensis – Henderson 1936b: pl. 2, fig. 6.
Goniobasis orickensis – Henderson 1936b: pl. 2 fig. 10.
Goniobasis yrekaensis – Henderson 1936b: pl. 2 figs 3–4.
Juga (Oreobasis) nigrina – Burch & Tottenham 1980: 154, fig. 453. — Burch 1982: 42, fig. 453; 1989: 154, fig. 453. — Frest & Johannes 1995b: 38 (in part); 2010: 10, 42, fig. 2d. — Holznagel & Lydeard 2000: 237 [identification later corrected in GenBank to Juga bulbosa]. — Campbell et al. 2016: fig. 2b.
Juga (Juga) silicula – Burch & Tottenham 1980: 152 (in part). — Burch 1982: 41 (in part); 1989: 152 (in part).
Juga nigrina – Turgeon et al. 1988: 65; 1998: 67. — Johnson et al. 2013: 282. — Köhler 2016: 270; 2017: 252.
Juga (Oreobasis) chacei – Frest & Johannes 1993: 64; 2000a: 305; 2010: 9, 29. — Campbell et al. 2016: 160.
Juga (Oreobasis) orickensis – Frest & Johannes 1993: 65; 2000a: 306; 2010: 11, 45. — Campbell et al. 2016: 160.
Juga (Oreobasis) “ nigrina ” – Frest & Johannes 1998: 28. — Johannes 2015: 30.
Juga (Juga) silicula shastaensis – Frest & Johannes 2005: 179; 2010: 48 [as possibly valid]. — Johannes 2013a: 24. — Campbell et al. 2016: 160.
Juga newberryi – Strong & Köhler 2009: 486.
Juga (Oreobasis) coquillensis – Frest & Johannes 2010: 31 [as possibly valid].
Juga (Juga) yrekaensis yrekaensis – Frest & Johannes 2010: 51 [as likely valid]. — Campbell et al. 2016: 160.
Juga (Juga) yrekaensis obscura – Frest & Johannes 2010: 43 [as dubiously valid].
Juga chacei – Johnson et al. 2013: 282.
Juga (Juga) coquillensis – Campbell et al. 2016: 160.
Juga shastaensis – Johannes & Clark 2016: 23–24.
Juga nigrina group – Strong & Whelan 2019: 89.
non Melania shastaensis – Reeve 1860: unpaginated, species 318, pl. 44 fig. 318. [= Juga occata]
non Juga (Oreobasis) “ nigrina ” – Frest & Johannes 1995b: 39. [= Juga canella sp. nov. and J. douglasi sp. nov.]; 2005: 179. [= Juga canella sp. nov.]
non Juga nigrina – Lydeard et al. 2002: 401. — Strong & Köhler 2009: 486. — Strong et al. 2011: 53. [= Juga plicifera]
Material examined
Lectotype of Melania nigrina I. Lea, 1856 (designated by Graf 2001: 71) (Fig. 22A) USA • “ Clear Creek, Shasta County, California ”; Dr Trask leg.; USNM 118992.
Paralectotypes of Melania nigrina I. Lea, 1856 USA • 23 spms; same collection data as for lectotype; USNM 1665631 (formerly USNM 118992X).
Lectotype of Melania shastaensis I. Lea, 1856 (designated by Graf 2001: 94) (Fig. 22B) USA • “ Shasta and Scott Rivers, California ” [type locality possibly erroneous; Henderson 1935a, 1936b]; Dr Trask leg.; USNM 119283.
Paralectotypes of Melania shastaensis I. Lea, 1856 USA • 26 spms; same collection data as for lectotype; USNM 1665632 (formerly USNM 119283X).
Lectotype of Goniobasis circumlineata Tryon, 1865 (designated by Baker 1964: 181) (Fig. 22C) USA • “Mission San Antonio, California ”; W. Newcomb leg.; ANSP 27573.
Paralectotypes of Goniobasis circumlineata Tryon, 1865 USA • 1 spm; “ Shasta Co., California ”; W. Newcomb leg.; ANSP 27574 • 2 spms; “ California ”; W. Newcomb leg.; USNM 12185.
Holotype of Goniobasis chacei Henderson, 1935 (Fig. 22D) USA • “ Small tributary of Smith River, Adams Station, Del Norte Co., Calif ” [possibly Mary’s Creek; Frest & Johannes 2010]; Oct. 1931; E.P. Chace leg.; UCM 18058a.
Paratype of Goniobasis chacei Henderson, 1935 USA • 1 spm (Henderson 1935a: pl. 2 fig. 8, at right); same collection data as for holotype; UCM 18058b.
Holotype of Goniobasis coquillensis Henderson, 1935 (Fig. 22E) USA • “ A creek at Riverton, on Coquille River, Oregon ” [possibly Alder Creek fide Frest & Johannes 2010]; Hannibal collection; UCM 21168a (incorrectly cited as 21167a in the original description).
Paratype of Goniobasis coquillensis Henderson, 1935 USA • 1 spm (Henderson 1935a: pl. 4 fig. 6, at right); same collection data as for holotype; UCM 21168b.
Holotype of Goniobasis orickensis Henderson, 1935 (Fig. 22F) USA • “ Redwood Creek, Orick, California ”; J. and B.R. Henderson leg.; UCM 17710a.
Paratypes of Goniobasis orickensis Henderson, 1935 USA • 2 spms (Henderson 1935a: pl. 4 fig. 10, at left and right); “ A creek 26 miles east of Arcata, California, by winding mountain road, almost certainly Redwood Creek ”; J. and B.R. Henderson leg.; UCM 17703a.
Holotype of Goniobasis yrekaensis Henderson, 1935 (Fig. 22G) USA • “ Shasta River, Calif., about 4 miles above the mouth, below Yreka ”; 6 Aug. 1931; J. and B.R. Henderson leg.; UCM 17735a.
Paratypes of Goniobasis yrekaensis Henderson, 1935 USA • 3 spms (Henderson 1935a: pl. 4 fig. 4); same collection data as for holotype; UCM 17735b.
Holotype of Goniobasis yrekaensis obscura Henderson, 1935 (Fig. 22H) USA • “ A creek two miles southwest of Wonder, Oregon ” [possibly Slate Creek or Butcherknife Creek; Frest & Johannes 2010]; 4 Aug. 1931; J. and B.R. Henderson leg.; UCM 17724a.
Other material examined 244 lots, 2062 specimens, of which 150 were sequenced.
USA – Oregon • 4 spms; Coos Co., Charleston, Sunset Bay State Park, Sunset Creek [sic, likely Big Creek]; [43.331, -124.3717]; 1951; I. Pratt leg.; USNM 598151 • 19 spms; Coos Co., Coos River; [43.3768, -124.1325]; USNM 56462 • 2 spms; same collection data as for preceding; USNM 56462 a • 32 spms; Coos Co., SH 425, just south of Riverton; 43.1162, -124.2901; 14 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295188 • 1 spm; same collection data as for preceding; GenBank: MK472387, MK464754, MK480861; USNM 1295185 • 1 spm; same collection data as for preceding; GenBank: MK472388, MK464755; USNM 1295186 • 1 spm; same collection data as for preceding; GenBank: MK472389, MK464756, MK480862; USNM 1295187 • 1 spm; same collection data as for preceding; GenBank: MK472386, MK464753; USNM 1295184 • 1 spm; same collection data as for preceding; GenBank: MK472385, MK464752; USNM 1295183 • 37 spms; Curry Co., Edson Campground; 42.8152, -124.4109; 13 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295102 • 1 spm; same collection data as for preceding; GenBank: MK472336, MK464703, MK480837; USNM 1295100 • 1 spm; same collection data as for preceding; GenBank: MK472337, MK464704; USNM 1295101 • 1 spm; same collection data as for preceding; GenBank: MK472332, MK464699; USNM 1295096 • 1 spm; same collection data as for preceding; GenBank: MK472333, MK464700; USNM 1295097 • 1 spm; same collection data as for preceding; GenBank: MK472334, MK464701; USNM 1295098 • 1 spm; same collection data as for preceding; GenBank: MK472335, MK464702; USNM 1295099 • 12 spms; Curry Co., Elk River Rd, just upstream of U.S. Hwy 101; 42.7861, -124.4811; 13 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295114 • 1 spm; same collection data as for preceding; GenBank: MK472346, MK464713, MK480841; USNM 1295112 • 1 spm; same collection data as for preceding; GenBank: MK472347, MK464714, MK480842; USNM 1295113 • 1 spm; same collection data as for preceding; GenBank: MK472343, MK464710, MK480839; USNM 1295109 • 1 spm; same collection data as for preceding; GenBank: MK472344, MK464711; USNM 1295110 • 1 spm; same collection data as for preceding; GenBank: MK472345, MK464712, MK480840; USNM 1295111 • 32 spms; Curry Co., Jack Creek; 42.062, -124.219; 14 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413269 • 1 spm; same collection data as for preceding; GenBank: MK472437, MK464804, MK480884; USNM 1413264 • 1 spm; same collection data as for preceding; GenBank: MK472438, MK464805, MK480885; USNM 1413265 • 1 spm; same collection data as for preceding; GenBank: MK472439, MK464806, MK480886; USNM 1413266 • 1 spm; same collection data as for preceding; GenBank: MK472440, MK464807, MK480887; USNM 1413267 • 1 spm; same collection data as for preceding; GenBank: MK472441, MK464808, MK480888; USNM 1413268 • 29 spms; Curry Co., Rogue River at Agness; 42.5578, -124.0595; 14 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413251 • 1 spm; same collection data as for preceding; GenBank: MK472422, MK464789; USNM 1413246 • 1 spm; same collection data as for preceding; GenBank: MK472423, MK464790, MK480874; USNM 1413247 • 1 spm; same collection data as for preceding; GenBank: MK472424, MK464791; USNM 1413248 • 1 spm; same collection data as for preceding; GenBank: MK472425, MK464792; USNM 1413249 • 1 spm; same collection data as for preceding; GenBank: MK472426, MK464793, MK480875; USNM 1413250 • 71 spms; Curry Co., Rogue River at Huntley Park; 42.4802, -124.3303; 14 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413257 • 1 spm; same collection data as for preceding; GenBank: MK472427, MK464794, MK480876; USNM 1413252 • 1 spm; same collection data as for preceding; GenBank: MK472428, MK464795, MK480877; USNM 1413253 • 1 spm; same collection data as for preceding; GenBank: MK472429, MK464796, MK480878; USNM 1413254 • 1 spm; same collection data as for preceding; GenBank: MK472430, MK464797, MK480879; USNM 1413255 • 1 spm; same collection data as for preceding; GenBank: MK472431, MK464798; USNM 1413256 • 14 spms; Curry Co., U.S. Hwy 101, Humbug Mountain State Park; 42.6837, -124.4222; 13 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295121 • 1 spm; same collection data as for preceding; GenBank: MK472348, MK464715; USNM 1295115 • 1 spm; same collection data as for preceding; GenBank: MK472349, MK464716, MK480843; USNM 1295116 • 1 spm; same collection data as for preceding; GenBank: MK472350, MK464717; USNM 1295117 • 1 spm; same collection data as for preceding; GenBank: MK472351, MK464718, MK480844; USNM 1295118 • 1 spm; same collection data as for preceding; GenBank: MK472352, MK464719, MK480845; USNM 1295119 • 1 spm; same collection data as for preceding; GenBank: MK472353, MK464720, MK480846; USNM 1295120 • 15 spms; Douglas Co., ~. 35 mi S of Hwy 138 (south of junction of NF4714 and NF4720); 43.3018, -122.6817; 13 Aug. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295029 • 1 spm; same collection data as for preceding; GenBank: MK472321, MK464688, MK480832; USNM 1295024 • 1 spm; same collection data as for preceding; GenBank: MK472322, MK464689; USNM 1295025 • 1 spm; same collection data as for preceding; GenBank: MK472323, MK464690; USNM 1295026 • 1 spm; same collection data as for preceding; GenBank: MK472324, MK464691; USNM 1295027 • 1 spm; same collection data as for preceding; GenBank: MK472325, MK464692; USNM 1295028 • 25 spms; Douglas Co., along SH 42, just SW of Winston; 43.1177, -123.4268; 14 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295170 • 1 spm; same collection data as for preceding; GenBank: MK472380, MK464747; USNM 1295165 • 1 spm; same collection data as for preceding; GenBank: MK472381, MK464748; USNM 1295166 • 1 spm; same collection data as for preceding; GenBank: MK472382, MK464749, MK480860; USNM 1295167 • 1 spm; same collection data as for preceding; GenBank: MK472383, MK464750; USNM 1295168 • 1 spm; same collection data as for preceding; GenBank: MK472384, MK464751; USNM 1295169 • 39 spms; Douglas Co., Cow Creek Rd at FS Rd 32-7-19; 42.7724, -123.5737; 14 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295194 • 1 spm; same collection data as for preceding; GenBank: MK472390, MK464757; USNM 1295189 • 1 spm; same collection data as for preceding; GenBank: MK472391, MK464758; USNM 1295190 • 1 spm; same collection data as for preceding; GenBank: MK472392, MK464759; USNM 1295191 • 1 spm; same collection data as for preceding; GenBank: MK472393, MK464760; USNM 1295192 • 1 spm; same collection data as for preceding; GenBank: MK472394, MK464761; USNM 1295193 • 11 spms; Douglas Co., Fort Umpqua; [43.7028, -124.1675]; Smithsonian leg.; USNM 119286 • 12 spms; Douglas Co., Glendale, Cow Creek; [42.7401, -123.4168]; W. Westgate leg.; USNM 334393 • 55 spms; Douglas Co., North Umpqua River at Amacher Park; 43.2816, -123.3564; 15 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413383 • 1 spm; same collection data as for preceding; GenBank: MK472466, MK464833; USNM 1413378 • 1 spm; same collection data as for preceding; GenBank: MK472467, MK464834, MK480904; USNM 1413379 • 1 spm; same collection data as for preceding; GenBank: MK472468, MK464835; USNM 1413380 • 1 spm; same collection data as for preceding; GenBank: MK472469, MK464836; USNM 1413381 • 1 spm; same collection data as for preceding; GenBank: MK472470, MK464837, MK480905; USNM 1413382 • 7 spms; Douglas Co., Roseburg, Umpqua River; [43.2108, -123.3525]; J. Henderson leg.; USNM 425496 • 19 spms; Douglas Co., Umpqua River; Andrus leg.; USNM 134591 • 48 spms; Douglas Co., Umpqua River at Sawyers Rapids; 43.6822, -123.6684; 15 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413377 • 1 spm; same collection data as for preceding; GenBank: MK472461, MK464828; USNM 1413372 • 1 spm; same collection data as for preceding; GenBank: MK472462, MK464829, MK480902; USNM 1413373 • 1 spm; same collection data as for preceding; GenBank: MK472463, MK464830, MK480903; USNM 1413374 • 1 spm; same collection data as for preceding; GenBank: MK472464, MK464831; USNM 1413375 • 1 spm; same collection data as for preceding; GenBank: MK472465, MK464832; USNM 1413376 • 14 spms; Douglas Co., Upstream of NF2823 bridge (downstream of log jam); 43.1071, -122.585; 12 Aug. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295036 • 1 spm; same collection data as for preceding; GenBank: MK472331, MK464698; USNM 1295035 • 1 spm; same collection data as for preceding; GenBank: MK472326, MK464693, MK480833; USNM 1295030 • 1 spm; same collection data as for preceding; GenBank: MK472327, MK464694, MK480834; USNM 1295031 • 1 spm; same collection data as for preceding; GenBank: MK472328, MK464695; USNM 1295032 • 1 spm; same collection data as for preceding; GenBank: MK472329, MK464696, MK480835; USNM 1295033 • 1 spm; same collection data as for preceding; GenBank: MK472330, MK464697, MK480836; USNM 1295034 • 7 spms; Douglas Co., Winchester, Umpqua River; [43.283, -123.3552]; J. Henderson leg.; USNM 425497 • 29 spms; Douglas Co., Yoncalla Creek at Boswell Rd; 43.6408, -123.2983; 15 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413365 • 1 spm; same collection data as for preceding; GenBank: MK472456, MK464823, MK480897; USNM 1413360 • 1 spm; same collection data as for preceding; GenBank: MK472457, MK464824, MK480898; USNM 1413361 • 1 spm; same collection data as for preceding; GenBank: MK472458, MK464825, MK480899; USNM 1413362 • 1 spm; same collection data as for preceding; GenBank: MK472459, MK464826, MK480900; USNM 1413363 • 1 spm; same collection data as for preceding; GenBank: MK472460, MK464827, MK480901; USNM 1413364 • 10 spms; Douglas Co.; T.J. L. leg.; USNM 509447 • 41 spms; Jackson Co., Jenny Creek at Pinehurst; 42.118, -122.366; 15 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413329 • 1 spm; same collection data as for preceding; GenBank: MK472451, MK464818, MK480894; USNM 1413324 • 1 spm; same collection data as for preceding; GenBank: MK472452, MK464819; USNM 1413325 • 1 spm; same collection data as for preceding; GenBank: MK472453, MK464820; USNM 1413326 • 1 spm; same collection data as for preceding; GenBank: MK472454, MK464821, MK480895; USNM 1413327 • 1 spm; same collection data as for preceding; GenBank: MK472455, MK464822, MK480896; USNM 1413328 • 28 spms; Jackson Co., near jct of Birdseye Creek Rd and Birdseye West Rd (37-4-4); 42.3845, -123.1748; 12 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295134 • 1 spm; same collection data as for preceding; GenBank: MK472360, MK464727, MK480847; USNM 1295129 • 1 spm; same collection data as for preceding; GenBank: MK472361, MK464728, MK480848; USNM 1295130 • 1 spm; same collection data as for preceding; GenBank: MK472362, MK464729, MK480849; USNM 1295131 • 1 spm; same collection data as for preceding; GenBank: MK472363, MK464730, MK480850; USNM 1295132 • 1 spm; same collection data as for preceding; GenBank: MK472364, MK464731, MK480851; USNM 1295133 • 18 spms; Jackson Co., Neil Creek; 42.1765, -122.6504; 15 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413298 • 1 spm; same collection data as for preceding; GenBank: MK472447, MK464814, MK480891; USNM 1413294 • 1 spm; same collection data as for preceding; GenBank: MK472448, MK464815, MK480892; USNM 1413295 • 1 spm; same collection data as for preceding; GenBank: MK472449, MK464816; USNM 1413296 • 1 spm; same collection data as for preceding; GenBank: MK472450, MK464817, MK480893; USNM 1413297 • 6 spms; Jackson Co., Rogue River at Rogue River City; 42.4313, -123.1711; 14 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413275 • 1 spm; same collection data as for preceding; GenBank: MK472442, MK464809; USNM 1413270 • 1 spm; same collection data as for preceding; GenBank: MK472443, MK464810, MK480889; USNM 1413271 • 1 spm; same collection data as for preceding; GenBank: MK472444, MK464811, MK480890; USNM 1413272 • 1 spm; same collection data as for preceding; GenBank: MK472445, MK464812; USNM 1413273 • 1 spm; same collection data as for preceding; GenBank: MK472446, MK464813; USNM 1413274 • 30 spms; Jackson Co., SH 234, Dodge Bridge County Park; 42.5261, -122.8427; 12 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295158 • 1 spm; same collection data as for preceding; GenBank: MK472377, MK464744; USNM 1295155 • 1 spm; same collection data as for preceding; GenBank: MK472378, MK464745, MK480859; USNM 1295156 • 1 spm; same collection data as for preceding; GenBank: MK472379, MK464746; USNM 1295157 • 1 spm; same collection data as for preceding; GenBank: MK472375, MK464742; USNM 1295153 • 1 spm; same collection data as for preceding; GenBank: MK472376, MK464743, MK480858; USNM 1295154 • 11 spms; Jackson Co., SH 62 just upstream of Casey State Recreation Area, Takelma Dr, near McGregor Park; 42.6589, -122.694; 12 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295140 • 1 spm; same collection data as for preceding; GenBank: MK472365, MK464732, MK480852; USNM 1295135 • 1 spm; same collection data as for preceding; GenBank: MK472366, MK464733, MK480853; USNM 1295136 • 1 spm; same collection data as for preceding; GenBank: MK472367, MK464734; USNM 1295137 • 1 spm; same collection data as for preceding; GenBank: MK472368, MK464735, MK480854; USNM 1295138 • 1 spm; same collection data as for preceding; GenBank: MK472369, MK464736, MK480855; USNM 1295139 • 35 spms; Josephine Co., North Fork Galice Creek; 42.5553, -123.6388; 14 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413169 • 35 spms; Josephine Co., North Fork Galice Creek Rd; 42.5531, -123.6324; 14 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295108 • 1 spm; same collection data as for preceding; GenBank: MK472340, MK464707; USNM 1295105 • 1 spm; same collection data as for preceding; GenBank: MK472341, MK464708; USNM 1295106 • 1 spm; same collection data as for preceding; GenBank: MK472342, MK464709; USNM 1295107 • 1 spm; same collection data as for preceding; GenBank: MK472338, MK464705, MK480838; USNM 1295103 • 1 spm; same collection data as for preceding; GenBank: MK472339, MK464706; USNM 1295104 • 23 spms; Josephine Co., Rogue River at Carpenter Island Park; 42.5595, -123.5984; 14 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413263 • 1 spm; same collection data as for preceding; GenBank: MK472432, MK464799, MK480880; USNM 1413258 • 1 spm; same collection data as for preceding; GenBank: MK472433, MK464800, MK480881; USNM 1413259 • 1 spm; same collection data as for preceding; GenBank: MK472434, MK464801; USNM 1413260 • 1 spm; same collection data as for preceding; GenBank: MK472435, MK464802, MK480882; USNM 1413261 • 1 spm; same collection data as for preceding; GenBank: MK472436, MK464803, MK480883; USNM 1413262 • 38 spms; Josephine Co., SH 199, 1.4 mi SW of Wonder; 42.348, -123.5594; 12 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295146 • 1 spm; same collection data as for preceding; GenBank: MK472370, MK464737, MK480856; USNM 1295141 • 1 spm; same collection data as for preceding; GenBank: MK472371, MK464738; USNM 1295142 • 1 spm; same collection data as for preceding; GenBank: MK472372, MK464739; USNM 1295143 • 1 spm; same collection data as for preceding; GenBank: MK472373, MK464740, MK480857; USNM 1295144 • 1 spm; same collection data as for preceding; GenBank: MK472374, MK464741; USNM 1295145 • 3 spms; Klamath Co., 16 mi NE of Dorris; [42.174, -121.7985]; USNM 404252 • 17 spms; Klamath Co., 2 mi N of Modoc Point; [42.4711, -121.8728]; 13 Aug. 1929; L. Sinitsin leg.; ditch by the highway; USNM 531428 • 2 spms; Klamath Co., Klamath Falls, L. Klamath; [42.2389, -121.8051]; W. Westgate leg.; USNM 334391 • 81 spms; Klamath Co., Klamath Falls, small creek by lab at Biological Survey on the lake; [42.2292, -121.7769]; 14 Aug. 1929; L. Sinitsin leg.; USNM 531319. – California • 4 spms; USNM 12140 a • 5 spms; same collection data as for preceding; USNM 56464 • 1 spm; same collection data as for preceding; H. Hemphill leg.; USNM 504245 • 2 spms; same collection data as for preceding; S. Smith leg.; USNM 218589 • 7 spms; Del Norte Co., 4 mi E of Klamath; [41.5378, -123.9379]; J. Henderson leg.; USNM 425495 • 15 spms; Del Norte Co., along SH 199, south side of Gasquette, former site of Adams Station; 41.8428, -123.9948; 13 Jul. 2014; J.T. Garner and N.V. Whelan leg.; USNM 1295128 • 1 spm; same collection data as for preceding; GenBank: MK472355, MK464722; USNM 1295123 • 1 spm; same collection data as for preceding; GenBank: MK472356, MK464723; USNM 1295124 • 1 spm; same collection data as for preceding; GenBank: MK472357, MK464724; USNM 1295125 • 1 spm; same collection data as for preceding; GenBank: MK472358, MK464725; USNM 1295126 • 1 spm; same collection data as for preceding; GenBank: MK472359, MK464726; USNM 1295127 • 1 spm; same collection data as for preceding; GenBank: MK472354, MK464721; USNM 1295122 • 13 spms; Del Norte Co., Klamath; [41.5257, -124.0426]; 7 Jul. 1951; USNM 665461 • 24 spms; Del Norte Co., Klamath River at Klamath Glen; 41.5152, -124.0003; 13 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413145 • 1 spm; same collection data as for preceding; USNM 1413140 • 1 spm; same collection data as for preceding; USNM 1413141 • 1 spm; same collection data as for preceding; USNM 1413142 • 1 spm; same collection data as for preceding; USNM 1413143 • 1 spm; same collection data as for preceding; USNM 1413144 • 31 spms; Del Norte Co., tributary of the Smith Creek [sic, Smith River]; 9 May 1929; L. Sinitsin leg.; USNM 531452 • 102 spms; Glenn Co., Brittain Ranch [sic, Brittan Ranch]; [39.3968, -122.6636]; 22 Mar. 1970; K.E. Lucas leg.; CASIZ 30022 • 7 spms; Humboldt Co., E of Willow Creek Campground, Hwy 299; [40.9452, -123.6566]; 16 Jun. 2015; B. Norman leg.; USNM 1436667 • 8 spms; Humboldt Co., near Orick, near hatchery; 9 May 1929; L. Sinitsin leg.; USNM 531473 • 84 spms; Humboldt Co., Redwood Creek at Chezem Rd; 40.9129, -123.8137; 13 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413066 • 1 spm; same collection data as for preceding; GenBank: MK472395, MK464762, MK480863; USNM 1413061 • 1 spm; same collection data as for preceding; GenBank: MK472396, MK464763; USNM 1413062 • 1 spm; same collection data as for preceding; GenBank: MK472397, MK464764; USNM 1413063 • 1 spm; same collection data as for preceding; GenBank: MK472398, MK464765, MK480864; USNM 1413064 • 1 spm; same collection data as for preceding; GenBank: MK472399, MK464766; USNM 1413065 • 47 spms; Humboldt Co., Redwood Creek at Orick; 41.2888, -124.0571; 13 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413122 • 1 spm; same collection data as for preceding; GenBank: MK472411, MK464778; USNM 1413116 • 1 spm; same collection data as for preceding; GenBank: MK472412, MK464779, MK480870; USNM 1413117 • 1 spm; same collection data as for preceding; GenBank: MK472413, MK464780; USNM 1413118 • 1 spm; same collection data as for preceding; GenBank: MK472414, MK464781; USNM 1413119 • 1 spm; same collection data as for preceding; GenBank: MK472415, MK464782, MK480871; USNM 1413120 • 1 spm; same collection data as for preceding; GenBank: MK472416, MK464783, MK480872; USNM 1413121 • 1 spm; Humboldt Co., Redwood Creek, Bair’s Ranch; [40.9638, -123.8405]; H.S. Barber leg.; USNM 193865 • 1 spm; Lake Co., Clear Lake; [39.0616, -122.8272]; Pease leg.; USNM 30647 • 4 spms; Mendocino Co., 10 mi N of Willets; [39.536, -123.4162]; 26 Jun. 1951; USNM 665462 • 11 spms; Mendocino Co., Cow Mountain; [39.1122, -123.109]; W.M. Gabb leg.; ANSP 27579 • 4 spms; Mendocino Co., Montgomery Creek at Montgomery Woods State Reserve; 39.2347, -123.3961; 12 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413072 • 1 spm; same collection data as for preceding; GenBank: MK472400, MK464767, MK480865; USNM 1413067 • 1 spm; same collection data as for preceding; GenBank: MK472401, MK464768, MK480866; USNM 1413068 • 1 spm; same collection data as for preceding; GenBank: MK472402, MK464769; USNM 1413069 • 1 spm; same collection data as for preceding; GenBank: MK472403, MK464770; USNM 1413070 • 1 spm; same collection data as for preceding; GenBank: MK472404, MK464771; USNM 1413071 • 2 spms; Mendocino Co.; H. Hemphill leg.; USNM 30552 • 6 spms; Mendocino Co.; USNM 59028 • 9 spms; Napa Co., Huichica Creek; [38.2145, -122.3564]; 8 Jul. 1980; L. Eng leg.; CASIZ 80989 • 12 spms; Napa Co., Oakville; [38.441, -122.395]; Brannan leg.; USNM 59040 • 17 spms; Napa Co., White Sulphur Springs; [38.49, -122.498]; Jul. 1877; J. Le Conte leg.; USNM 58932 • 25 spms; Shasta Co., Clear Creek at French Gulch; 40.7048, -122.6366; 11 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413115 • 1 spm; same collection data as for preceding; GenBank: MK472405, MK464772, MK480867; USNM 1413109 • 1 spm; same collection data as for preceding; GenBank: MK472406, MK464773; USNM 1413110 • 1 spm; same collection data as for preceding; GenBank: MK472407, MK464774, MK480868; USNM 1413111 • 1 spm; same collection data as for preceding; GenBank: MK472408, MK464775; USNM 1413112 • 1 spm; same collection data as for preceding; GenBank: MK472409, MK464776; USNM 1413113 • 1 spm; same collection data as for preceding; GenBank: MK472410, MK464777, MK480869; USNM 1413114 • 6 spms; Siskiyou Co., 4 mi above mouth of Shasta River; [41.7863, -122.6017]; J. Henderson leg.; USNM 425494 • 4 spms; Siskiyou Co., Klamath River at Klamathton; [41.8999, -122.505]; 1899; R.C. McGregor leg.; ANSP 76792 • 7 spms; Siskiyou Co., O’Neil Creek; [41.8105, -123.1158]; W.B. Murbarger leg.; USNM 467207 • 8 spms; Siskiyou Co., Scott River, 8 mi above Scott Bar; [41.6767, -123.1016]; L. Shapovalor leg.; ANSP 179318 • 7 spms; Siskiyou Co., Scott River, Scott River Resort [Scott River Lodge]; [41.6795, -123.1]; 23 Jun. 1948; M.L. Walton leg.; ANSP 347189 • 46 spms; Siskiyou Co., Shasta River below Hwy 263 Bridge; 41.807, -122.5938; 14 Sep. 2015; E.E. Strong and P. Bouchet leg.; USNM 1413128 • 1 spm; same collection data as for preceding; GenBank: MK472417, MK464784; USNM 1413123 • 1 spm; same collection data as for preceding; GenBank: MK472418, MK464785; USNM 1413124 • 1 spm; same collection data as for preceding; GenBank: MK472419, MK464786; USNM 1413125 • 1 spm; same collection data as for preceding; GenBank: MK472420, MK464787; USNM 1413126 • 1 spm; same collection data as for preceding; GenBank: MK472421, MK464788, MK480873; USNM 1413127 • 12 spms; Sonoma Co., Adobe Creek; [38.2343, -122.5978]; ANSP 120900 • 1 spm; Sonoma Co., Austin Creek State Recreation Area, East Austin Creek, Black Rock Creek to road crossing in Recreation Area; [38.5594, -123.0564]; 10 Jul. 1979; L. Courtois leg.; CASIZ 169957 • 2 spms; Sonoma Co., Austin Creek State Recreation Area, East Austin Creek, vicinity of road crossing; [38.5359, -123.0721]; 10 Jul. 1970; L. Eng leg.; CASIZ 85269 • 18 spms; Sonoma Co., Buckeye Spring, on The Geysers Rd; [38.7414, -122.8289]; 28 Aug. 1979; J. Landye leg.; on rocks and sand; USNM 892379 • 6 spms; Sonoma Co., Cloverdale; [38.816, -123.0111]; USNM 58994 • 3 spms; same collection data as for preceding; USNM 56426 • 207 spms; Sonoma Co., Cold Springs, S of Sulphur Creek, The Geysers, 0.5 km S, 0.8 km E from NW corner; [38.7531, -122.8242]; 26 Aug. 1979; J. Landye leg.; on rocks, leaves, dead wood; USNM 903672 • 8 spms; Sonoma Co., Duncans Mills; [38.4541, -123.0495]; USNM 56425 • 27 spms; Sonoma Co., Gualala River, Wheatfield Fork; USFC; Gilbert leg.; USNM 109894 • 12 spms; Sonoma Co., Healdsburg; W. Gregg leg.; USNM 1501084 • 13 spms; Sonoma Co., in spring on E Side of U.S. Hwy 101, 0.9 mi N of Hwy 101 bridge over Russian River; [38.6055, -122.8708]; 25 Aug. 1979; J. Landye leg.; USNM 892371 • 53 spms; Sonoma Co., Mr Martin’s Ranch [Silas W Martin Dairy, in Two Rock, near Petaluma]; [38.2426, -122.7525]; 17 Apr. 1929; L. Sinitsin leg.; USNM 531206 • 4 spms; Sonoma Co., 1.15 mi NE of junction of California Hwy 1 and 12, 550 ft NW of BM 27, Duncans Mills Area; [38.4495, -123.0948]; 21 Sep. 1966; J. Landye and D.W. Taylor leg.; in spring trickle on N side of Russian River; USNM 905121 • 9 spms; Sonoma Co., Sonoma Creek; [38.2773, -122.4719]; W. Sutton leg.; USNM 509435 • 4 spms; same collection data as for preceding; J. Rowell leg.; ANSP 27575 • 3 spms; Sonoma Co., The Geysers; [38.7748, -122.7552]; Kelsey leg.; USNM 153054 • 3 spms; Sonoma Co.; H. Hemphill leg.; USNM 30556 • 7 spms; Sonoma Co.; J.G. Cooper leg.; USNM 28929 • 1 spm; Trinity Co., North Fork of the Trinity River, East Fork of the North Fork of the Trinity River, tributary, Brock Creek [sic, Brock Gulch]; [40.7881, -123.1242]; 6 Jun. 1978; Del Sarto leg.; CASIZ 85263 • 2 spms; Trinity Co., Trinity River, tributary, Dutton Creek; [40.675, -122.9704]; 20 Jun. 1978; Del Sarto leg.; CASIZ 85222 • 81 spms; 3 mi N of Golden Beach [sic]; 15 Aug. 1951; USNM 665463.
Description
SHELL. Thin to moderately thick, large, usually not exceeding ~ 2.5 cm, exceptionally reaching ~ 3.75 cm in length; turriform, narrowly conical to cylindrical in shape, spire moderate to high, highly variable in sculpture, color, and banding (Fig. 23). Whorls somewhat flattened to convex, occasionally weakly shouldered or with a subsutural ramp, suture weakly to deeply impressed. Aperture oval in shape, occasionally flattened at the base, lip smooth, simple to slightly sinuous. Spiral sculpture of fine striae, indistinct to moderately developed, highly variable in strength and number; later whorls occasionally with few, indistinct elevated lirae. Axial sculpture of fine, orthocline, weakly opisthocyrt to sinuous growth lines; plications present or absent, confined to upper part of spire; plications regular to somewhat irregular, weakly to moderately developed, occasionally shouldered, orthocline to moderately opisthocyrt; may be thickened or beaded at intersections with spiral striae. Shell black, dark brown, to olive, tan or yellowish in color. Bands present or absent, one to three in number and variable in width, reddish-purple in color. Interior of aperture white or cream to dark purple in color. Base of columella occasionally tinged reddish-purple
RADULA. Rachidian narrowly rectangular, wider than tall, with convex lower margin and small, bluntly pointed, basal denticles at lower, outer corners (Fig.24). Upper margin slightly concave with cutting edge bearing central, elongate conical cusp, and two to three stout, conical denticles on each side. Lateral teeth with prominent triangular cusp flanked by two to three inner and two to three outer, triangular denticles, and occasionally a membranous outermost denticle. Marginal teeth with broadly rounded cutting edges and long, slender, flattened shafts with membranous flanges along inner and outer edges. Narrow inner flanges along distal half to two-thirds of shafts; broad outer flanges extending almost to tooth bases. Inner marginal teeth with ~five, and outer marginal teeth with six to seven flattened denticles.
Distribution and ecology
In small creeks to large rivers primarily in coastal drainages from south-central Oregon to central California (Fig. 21B).
Remarks
Melania nigrina and M. shastaensis were established simultaneously by Lea (1856). Melania shastaensis was first synonymized with Goniobasis occata by Reeve (1860), followed by Brot (1862), an error resulting from a misidentified specimen that was labeled as originating from the author (“authentic”; Tryon 1865: 237; 1873: 146). Tryon (1864) synonymized shastaensis with silicula which has been followed by most subsequent authors (Tryon 1865, 1866, 1873; Henderson 1929; Goodrich 1942; Burch & Tottenham 1980; Burch 1982, 1989), apart from Pilsbry (1899) who synonymized the species with plicifera. Henderson (1935a, 1936b) recognized the species as a distinct variety of silicula which was followed by Frest & Johannes (2010). Campbell et al. (2016: 167) noted that their sequenced specimen of J. (J.) silicula shastaensis was supported in a different clade from J. (J.) silicula silicula but did not address its taxonomic status. Thus, the fact that nigrina and shastaensis represent the same taxonomical species is new. We here take the right of First Reviser (Art. 24.2.2; ICZN, 1999), and establish the precedence of nigrina over shastaensis.
Although it is not known precisely where in Clear Creek the types of Melania nigrina originated, this creek has been severely affected by impoundment and gold dredging and many sites still lack Juga (Frest & Johannes 2010). However, refugial populations in several large tributaries seem to be repopulating the main course near their junctions with Clear Creek. Frest & Johannes (2010) noted the discrepancy between Lea’s (1856, 1863a, 1863b) description and the type specimens (Fig. 22A), which do not appear as nearly black and polished with a dark purple interior as the description would suggest. Near topotypic specimens from Clear Creek at French Gulch (Fig. 23T) were included in the analysis of Strong & Whelan (2019), which showed a range of variation from those yellow-brown in color with a light interior similar to the type, to those black in color with a dark purple interior (Fig. 23U) matching the original description.
The type locality of Melania shastaensis was indicated to be Shasta and Scott Rivers, California (Lea 1856). Lea (1863a, 1863b) later added “Fort Umpqua, O.T. [Oregon Territory]” to the list of habitats with the Smithsonian as collector, which refers to USNM 119286 from the Lea collection. However, this material has no type status as it was not originally included. Henderson (1935a, 1936b) questioned whether the original type locality was erroneous, having seen no material from the Shasta River that matched the description, and considered the types more similar to material from the Umpqua River, an opinion shared by Frest & Johannes (2010). Henderson submitted specimens from the Shasta, Klamath and Umpqua Rivers to the USNM for comparison with the type of shastaensis and received the following reply from curator Harald Rehder, “[the types of Goniobasis shastaensis Lea] are more like those from the Umpqua River. […] Whether Lea’s type lot (from Scott and Shasta Rivers) really came from either or both of those rivers, or whether we are here dealing with a confusion of localities, I cannot tell” (Henderson 1935a: 95; 1936b: 276). Owing to his doubts over the precision of the type locality, Henderson (1935a) described material in his possession from the Shasta River as Goniobasis yrekaensis. Henderson (1936b) later reported receiving specimens from the Scott River that agreed well with the original description of shastaensis, as did specimens from the Umpqua River drainage and elsewhere in western Oregon. Efforts to recollect from the Scott River were unsuccessful (Frest & Johannes 2010). Ultimately, however, the ambiguity is of little consequence as the same taxonomical species (J. nigrina) is found in both the Klamath and Umpqua River drainages.
The type locality of Melania circumlineata is the Mission San Antonio in Monterey County, California, but is widely assumed to be in error (Henderson 1932; Taylor 1981; Frest & Johannes 2010) as it lies far to the south of the documented distribution of Recent Juga (Fig. 21B). It was not infrequent in those times that specimens brought back to natural history museums “from the seats of trade” (Carpenter 1857: 162), or from the seats of worship (e.g., Neubert et al. 2009), took incorrect provenance. Cooper (1894) indicated San Antonio Creek as the southern extent of Goniobasis circumlineata. This creek, which forms part of the boundary between Marin and Sonoma Counties, is a tributary of the Petaluma River, which flows into the northwestern corner of San Pablo Bay. Henderson (1932) quoted a personal communication from G.D. Hanna who pointed out that there are many San Antonio Creeks in California, but agreed that the one cited by Cooper may be the source of the type material. Hanna referred to an unconfirmed report of a chapel on the San Antonio Rancho at the head of the creek.
Several museum lots (e.g., Fig.23 A’)collected in southern Sonoma and Napa Counties are morphologically similar in size, shape, color and proportion to the lectotype of circumlineata. Pilsbry (1899) and Walker (1918) considered it to be likely only a variety of nigrina; Frest & Johannes (2010) agreed that the type may be a decollate “ nigrina ” s. lat. Campbell et al. (2016: supp. file 1) reported this species could represent a number of smooth-shelled forms but were not able to analyze it. In addition to specimens from Mission San Antonio and Shasta County, California, both received from W. Newcomb, Tryon’s (1865) concept of Goniobasis circumlineata included specimens collected by J.S. Newberry from the Pit River, and specimens from J.H. Thomson from the Feather River. Possible type material from the latter two localities has not been located and could potentially represent Juga occata, J. douglasi sp. nov., or both, but not J. nigrina, which does not extend that far east. Tryon (1873) later omitted circumlineata without comment and did not reproduce his earlier figures.
Attempts to locate type material of Melania californica have been unsuccessful. Clessin’s collection was in Stuttgart, Germany, and was reportedly destroyed during World War II (Tomlin 1947: 288). Although parts of the collection evidently remain intact in the Stuttgart Museum, no types of this species are found there (I. Richling, pers. com.). Clessin (1882) attributed the locality information (“California”) as communicated (“ com. ” = communicavit) from H. von Heimburg of Oldenburg. Parts of von Heimburg’s collection, particularly the freshwater parts, were purchased and re-assembled by C. Bosch, whose collection was received by the Senckenberg in 1962 (Zilch 1967). However, there is no type or topotypic material of this species in the Senckenberg (J. Sigwart, R. Janssen, pers. com.). Thus, on the merits of the originally published figure, we tentatively consider californica to be a synonym of nigrina. This synonymy was first proposed by Pilsbry (1899) and followed by Walker (1918), Henderson (1929, 1935a, 1936b), and Taylor (1981). Frest & Johannes (2010) found Taylor’s (1981) synonymy with nigrina to be plausible but noted that it could be a nigrina -like form and suggested the common name California Juga. Campbell et al. (2016: supp. file 1) reported this species could represent a number of smooth-shelled forms but were not able to analyze it. Other authors have ignored the name.
Topotypic or near topotypic specimens for all five of Henderson’s (1935a) nominal species established from northern California (Goniobasis chacei, G. coquillensis, G. orickensis, G. yrekaensis, and G. y. obscura) were included in the molecular analysis of Strong & Whelan (2019) (Fig. 23F, M–N, S, V–W) and are conspecific with topotypic specimens of nigrina (Fig. 23T–U). All five were regarded as species incerta by Goodrich (1942). Burch & Tottenham (1980) and Burch (1982, 1989) did not mention any of them; nor did Turgeon et al. (1988, 1998). Taylor (1981) considered only Juga (Oreobasis) chacei and J. (O.) orickensis as valid, of which only the former was retained in the list of Johnson et al. (2013). Frest & Johannes (2010) considered all as valid, or potentially so, except yrekaensis obscura, which they synonymized with yrekaensis. Campbell et al. (2016: supp. file 1) supported the synonymy of obscura with yrekaensis but they did not address the taxonomic status of Henderson’s other nominal species. Thus, the explicit synonymy of all five nominal species with nigrina here is new.
Specimens identified as Juga (Oreobasis) “ nigrina ” from the Upper Klamath River drainage by Frest & Johannes (1998) and Johannes (2015) are hypothesized here to represent true nigrina, but this will require confirmation with molecular data. Frest & Johannes (1998, 2005) reported that they had found no ribbed forms in this area. However, USNM 334391 from Klamath Falls is a lot of two juvenile specimens which display regular plications typical of nigrina. The other three historical lots from Klamath County are all eroded but are rather high spired and cylindrical with a moderately impressed suture and are cautiously interpreted as representing true nigrina as well. However, it is possible they could represent a mixture of nigrina and smooth forms of J. canella sp. nov., which would extend the distribution of the latter to the east. The OTU referred to as Juga (Oreobasis) “ nigrina ” (Frest & Johannes 2005 = Schoolhouse Meadow Juga) and later as Juga (O.) n. sp. (Johannes 2013a = Spring Creek Juga) from the Cascade-Siskiyou National Monument comprises smooth forms of J. canella. The OTU referred to as J. (O.) “ nigrina ” (Frest & Johannes 1995b = Smooth River Juga) from the Upper Sacramento System is a mixture of J. canella. and J. douglasi sp. nov. as circumscribed here. The axially ribbed forms of true nigrina that occur in the Cascade-Siskiyou National Monument have been referred to as J. (J.) silicula shastaensis (Frest & Johannes 2005; Johannes 2013a). Populations from Sacramento River drainages of the western foothills of the Sierra Nevada have been attributed primarily to J. nigrina (e.g., Lowe 1916; Taylor, 1981; Frest & Johannes 1995b; Brim Box 2002; Brim Box et al. 2005) or to a potentially new species (Frest & Johannes 2007) and are interpreted here as representing J. douglasi (see account above). As confirmed by sequenced specimens, J. nigrina is known only as far east in California as the McCloud River drainage in northwestern Shasta County and does not occur in the Sierra Nevada.
Distribution
Historical museum records place the species in southern Sonoma and Napa Counties, California, in the north San Pablo Bay watershed. The southernmost populations previously documented were from Salmon Creek and nearby Occidental in Pacific drainages of western Sonoma County (Henderson 1932). Taylor (1981) noted that the population in Salmon Creek was presumed extirpated. However, an observation record in iNaturalist (https://www.inaturalist.org/observations/11249251) has documented an extant population in Salmon Creek, an observation we have confirmed; this record and others from the area indicate that isolated populations in southern Sonoma and Napa Counties are still extant.
Common name
The common name for this species is the Black Juga (Turgeon et al. 1988, 1998; Frest & Johannes 1995b, 2010; Johnson et al. 2013). Synonyms have been referred to as the Shasta Juga (J. (J.) silicula shastaensis), Chace Juga (J. chacei), and Redwood Juga (J. orickensis) (Frest & Johannes 1993, 2005, 2010; Johannes 2013a; Johnson et al. 2013). The OTU referred to as J. (O.) nigrina (Frest & Johannes 1995b = Black Juga) from the Upper Sacramento System is a mixture of true J. nigrina and J. douglasi sp. nov. as circumscribed here.
description: Published as part of Strong, Ellen E., Garner, Jeffrey T., Johnson, Paul D. & Whelan, Nathan V., 2022, A systematic revision of the genus Juga from fresh waters of the Pacific Northwest, USA (Cerithioidea, Semisulcospiridae), pp. 1-97 in European Journal of Taxonomy 848 on pages 60-74, DOI: 10.5852/ejt.2022.848.1993, http://zenodo.org/record/7427764