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Terrestrial
Gastropods of the Columbia Basin, British Columbia
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| Family POLYGYRIDAE Pilsbry,
1895
For taxonomic changes since Pilsbry
(1939), see Emberton (1995).
Genus Cryptomastix Pilsbry, 1939 Cryptomastix mullani
(Bland & Cooper, 1881): Coeur d'Alene Oregonian
Description: Shell medium-sized (width to 16 mm), more or less depressed-heliciform and reddish or yellowish brown, with a matt or polished surface; spire low-conical to almost flat; whorls convex and numbering 4¾-5½; whorls slowly enlarging in width; periphery rounded; suture deep; last whorl not descending at the aperture; protoconch with rows of minute granules; teleoconch with low, rounded, irregular axial ribs and fine striae, and sometimes with weak spiral striae; occasional, small, weak malleations may be present on the last portion of the last whorl; periostracum with minute hairs in juveniles and some adults, but most adults without hairs; aperture subovate; parietal denticle short and white, but occasionally absent in some adults; columellar and basal lip thickened, strongly recurved and white; basal lip with a ridge like callus and medially located swelling; outer lip white, rather thickened, very strongly recurved, broadly expanded and with a slight posterior swelling; last whorl very slightly contracted behind outer lip; a rounded crest is present behind the outer lip; umbilicus small, 12-15% of the width of the shell and partially overhung by the expanded outer lip. Similar Species: The shell of Cryptomastix mullani is larger and generally flatter-spired than the coastal C. germana (Gould in W.G. Binney, 1851). The other coastal Cryptomastix, C. devia (Gould, 1846), is larger than C. mullani and has the thickest point of the swelling on the basal lip located relatively closer to the columella than to the periphery. Specimens of C. mullani lacking a parietal denticle are likely to be confused with Vespericola columbianus (I. Lea, 1838), which however, has the outer lip strongly flared outward but not rolled over.
Habitat: In British Columbia, Cryptomastix mullani has been found in the vicinity of streams, under rocks, logs, leaf litter and vegetation. According to Vagvolgyi (1968) predominantly between 457-1,829 m [1,500-6,000 ft], but sometimes as low as 152 m [500 ft ]. Range: Southeast British Columbia; Washington east of the Cascade Mountains to northeast Oregon and east through Idaho to western Montana (Pilsbry 1940). Distribution: In British Columbia, previously reported only from Vernon (Pilsbry 1940). This species has been collected in the Kootenay, Columbia, Arrow Lake valleys, as far north as Eagle Pass west of Revelstoke. Notes: Pilsbry (1940) referred shells from Vernon to the 'subspecies' olneyae, of which the type locality is Spokane, Washington; he recognised a number of named forms or 'subspecies', including olneyae, which have since been placed in the synonymy of Cryptomastix mullani mullani by Vagvolgyi (1968). Name: Genus name derived from anatomical distinctions with related genera, and meaning hidden flagellum. Species name in honour of American Captain Mullan, who built a road over the Bitter Root and Rocky Mountains in 1853-1854 (Pilsbry 1940). Records: Kuskanook Rest Area, Hwy 3A,
E side of Kootenay Lake (49°17.11'N, 116°39.17'W) (Forsyth
Collection 97-101-1006); Lodgepole Creek Road, SE of Fernie (49°20.01'N,
114°56.67'W) (RBCM 998-00296-001); Syringa Creek, Lower Arrow
Lake (circa 49°21.1'N, 117°54.6'W) (Forsyth Coll.
97-113-4259); Nelson (49°30'N, 117°17'W) (RBCM 991-00095-005);
Lockhart Creek, E shore of Kootenay Lake (49°30.6' N, 116°
47.1' W) (Forsyth 97-099-1039); W side of Slocan River, just S of
Winlaw (49°35.66'N, 117°35.47'W) (RBCM 998-00279-004); N
end of Slocan Lake, near hills (49°54.04'N, 117°23.25'W)
(RBCM 998-00266-002); Roadside, Hwy 1, Eagle Pass, E of Clanwilliam,
W of Revelstoke (50°58.2'N, 118°21.0'W) (Forsyth Coll. 98-097-3284).
View the map.
Genus Allogona Pilsbry, 1939
Allogona ptychophora
(A.D. Brown, 1870): Idaho Forestsnail
Allogona ptychophora 
Description: Shell rather large (width to 23.7 mm), heliciform; surface matt or a little shiny, brownish or straw yellow; spire moderately elevated, but somewhat variable; whorls 5.25-5.75, convex; periphery rounded; suture deep; last part of the last whorl descending at lip; protoconch smoothish; teleoconch with fine axial striae and irregular, lighter-coloured wrinklelike axial riblets; exceedingly fine, wavy spiral striae throughout, but not visible on eroded shells; surface rarely malleated; periostracum not hirsute and sometimes mostly eroded away; aperture subovate, without a parietal denticle; columellar and basal lip white; basal lip heavy, thickened, and with a slight bulging callus at its junction with the columellar lip; outer lip thickened within and strongly reflected; last whorl scarcely contracted behind lip; crest very low or absent; umbilicus small, about 10% of the width of the shell, and partially concealed by the expanded and reflected columellar lip. Juveniles lack the reflected, thickened outer lip and have the periphery slightly angled. Within populations of this snail a few are paler, of a yellowish straw-colour, and in this respect, is similar to the coastal species Allogona townsendiana (I. Lea, 1838), which also shows variation in colour. Similar Species: The shell chiefly differs from A. townsendiana (I. Lea, 1838) by its slightly smaller size and generally less malleated ornamentation. A. lombardii A.G. Smith, 1943, is also similar (see Notes below). Habitat: Under leaf litter, grass, rocks and logs, and on ground in open or in woods. Sometimes very abundant. In Montana, reported at 2,590 m [8,500 ft] (Vanatta 1914). Range: Southern British Columbia south through Montana and Idaho and west down the Columbia River valley of Washington and Oregon (Pilsbry 1940). Distribution: Allogona ptychophora is common and generally spread in the southern Kootenay, Columbia and Elk river drainages, at least as far north as Revelstoke. Elsewhere in British Columbia A. ptychopora is known from Vernon (Pilsbry 1940) and Salmon Arm (RBCM 998-00018-001). Notes: Smith (1943) suggested that specimens of Allogona from Boswell, British Columbia were Allogona lombardii A.G. Smith, 1943, which is said to differ from A. ptychophora by its larger size, heavier texture and more prominent ribbing. This British Columbia record of the A. lombardii is, however, unsubstantiated; Smith stated that the Boswell shells were similar to A. lombardii in sculpture but not in size, and that the specimens should probably take that name. All Allogona from southeast British Columbia are here considered to be A. ptychophora pending a more reliable means of separating A. lombardii and A. ptychophora. Name: Genus name in reference to the anatomy and meaning "different genitalia". Species name meaning "bearing folds" and describing the sculputure of the shell. Records: Creek Marsh, S end of Creston Valley Wildlife Management Area (49°05.64'N, 116°37.31'W) (RBCM 998-00281-001); Trail (49°06'N, 117°42'W) (Whiteaves 1906); Creston Valley Wildlife Management Area (49°07.34'N, 116°37.24'W) (RBCM 998-00264-004); Glenmarry Creek Road, near Nancy Greene Provincial Park (49°15.94'N, 117°56.36'W) (RBCM 998-00280-001); Lodgepole Creek Road (49°17.03'N, 114°42.72'W) (RBCM 998-00296-004); Kuskanook Rest Area, Hwy. 3A, E side of Kootenay Lake (49°17.11'N, 116°39.17'W) (Forsyth Coll. 97-101-1009); Syringa Creek Provincial Park, Lower Arrow Lake (circa 49°21.1'N, 117°54.6'W) (Forsyth Coll. 97-113-4240); Betania Road near Sand Creek, E end of Betania Road, S side of Hwy 3/93, W of Galloway (49°22.23'N, 115°14.59'W) (Forsyth Coll. 97-105-907); Boswell (49°27'N, 116°46'W) (Pilsbry 1940); Elk River valley, along Hwy 3, S of Fernie (circa 49°27.5'N, 115°04.2'W) (Forsyth Coll. 97-109-1016); Hepher Road at Hwy 3A, Boswell (49°28.46'N, 116°46.0'W) (Forsyth Coll. 97-100-864); Coal Creek at Cokato Road, Fernie (49°29.72'N, 115°03.75'W) (Forsyth Coll. 97-108-1048); "Cold Creek valley" [likely in error for Coal Creek (circa 49°30'N, 115°04'W)] near Fernie (Pilsbry 1940); Cranbrook (49°30'N, 115°46'W) (Pilsbry 1940); Nelson (49°30'N, 117°17'W) (RBCM 991-00095-006); Hwy 3 near Hosmer (49°34.94'N, 114°58.05'W) (RBCM 998-00299-002); Kokanee Landing (49°36'N, 117°06'W) (RBCM 996-00010-005, 996-00010-006); Kokanee Creek Provincial Park, Kootenay Lake (49°36.2'N, 117°07.7'W) (Forsyth Coll. 97-095-1084); Crowsnest Pass (49°38'N, 114°41'W) (Whiteaves 1906, Pilsbry 1940); Cummings Creek, N of Sparwood (49°46.32'N, 114°54.95'W) (RBCM 998-00293-002); Blanket Creek Provincial Park, S of Revelstoke (50°50'N, 118°05'W) (Staatliches Museum für Naturkunde Görlitz p5958); along Hwy 1, W of Revelstoke, B.C., at junction with Hwy 23. (51°0.2'N, 118°13.4'W) (Forsyth Coll. 98-096-3320). "Sproat" (Whiteaves 1906), possibly a locality in the vicinity of Mt. Sproat (50°45'N, 117°54'W) at the north of the north end of Upper Arrow Lake. View the map. |
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