Hoplopleura altaiensis n. sp. (Figs. 1–3) Male (Figs. 1A, B, 2A, C) (n ¼ 9): Total body length of holotype, 0.945 mm (mean, 0.916 mm; range, 0.878 –1.028 mm). Head, thorax, and abdomen moderately sclerotized. Head (Fig. 1A, B): Longer than wide with broadly curved lateral margins posterior to antennae and extended anteriorly; distinct dorsal lobe on each side posterior to head suture; maximum head width of holotype, 0.150 mm (mean, 0.151 mm, range, 0.150 –0.152 mm). Antennae 5-segmented with fairly broad basal segment and slightly elongated second segment; no antennal segments highly modified. One distinct ventral principal head seta, 2 ventral preantennal setae, 2 sutural head setae, 4 dorsal marginal head setae, 2 dorsal anterior head setae, 1 dorsal anterior central head seta, 1 dorsal posterior central head seta, 1 dorsal principal head seta, 1 small dorsal accessory head seta, 2 supra-antennal head setae, 1 small dorsal preantennal head seta, and 4–6 apical head setae on each side. Thorax (Fig. 1A, B): Broader than head; maximum thorax width of holotype, 0.205 mm (mean, 0.211 mm; range, 0.205 – 0.216 mm). Thoracic sternal plate (Fig. 1B) somewhat shieldshaped; long posterior extension with squarish posterior margin, small anterior projection, and small lateral indentation on each side. Thoracic fragma distinct. Mesothoracic spiracle diameter of holotype, 0.016 mm (mean, 0.016 mm; range, 0.015 –0.017 mm). Dorsal principal thoracic seta (DPTS) length of holotype, 0.103 mm (mean, 0.104 mm; range, 0.100 – 0.108 mm). Legs each terminating in tibio-tarsal acuminate claw; claw on hindlegs broader than claws on fore and midlegs; forelegs slightly smaller than midlegs; midlegs slightly smaller than hindlegs; leg coxae variously shaped (Fig. 1B). Abdomen (Fig. 1A, B): Broader than thorax with 13 tergites and 10 sternites. Tergites 1 and 3 fairly broad; tergite 1 partially separated medially; tergites 2 and 4 very broad each with diverging acuminate posterio-lateral margins; tergites 4–13 wider than previous tergites; tergite 13 distinctly curved. Sternites 1 and 2 broader than other sternites; sternites 2 and 3 each articulating laterally with corresponding paratergal plate (as characteristic of genus); sternites 3–10 each fairly narrow. Tergite 1 lacking tergal abdominal setae (TeAS); tergites 2 and 3 each with 1 long TeAS and 1 very long TeAS on each side; tergites 4–12 each with 7–12 long TeAS; tergite 13 with 4 small setae on each side. One dorsal marginal abdominal seta (DMAS) lateral to tergites 5–12 on each side. Sternites 1 and 2 each with 7 long sternal abdominal setae (StAS); 2 lateral StAS on each side of sternite 2 slightly diverging with medial of each of these pairs of StAS much more robust than lateral StAS. Sternites 3–10 each with 7–8 long StAS. One ventral marginal abdominal seta (VMAS) on each side lateral to each of sternites 5–13. Paratergal plates (Figs. 1A, B, 2A): Present on abdominal segments 1–8. Plate I small and lacking apical setae. Plates II–V subtriangular; plate VI subrectangular; plates VII and VIII subeliptical. Plates III–VII each with small spiracle. Plates II–VI each with 2 paratergal setae (PrS) of moderate length; plates VII and VIII each with 2 very long PrS; PrS setae on plates II and III slightly thickened. Genitalia (Fig. 2C): Basal apodeme slightly longer than parameres and with moderately sclerotized, postero-lateral extensions. Parameres fairly straight in anterior section and then broadly curved. Pseudopenis extending posteriorly well beyond posterior apices of parameres and with lateral extensions. Subgenital plate (Fig. 1B) surface distinctly spiculate and extending anteriorly to paratergal plate VI, with slightly concave anterior margin, sinuous lateral margins, tapering posteriorly, and differentially sclerotized as represented by 2 distinct horizontal bands; small central lacuna present anteriorly with 3 very long setae inserted along posterior margin; 2 very long setae inserted along posterior margin of middle sclerotized band. Female (Figs. 2B, D, 3A, B) (n ¼ 7): Total body length of allotype, 1.275 mm (mean, 1.264 mm; range, 1.198 –1.345 mm). Head, thorax, and abdomen as in male unless indicated otherwise. Head (Fig. 3A, B): Maximum head width of allotype, 0.161 mm (mean, 0.161 mm; range, 0.161 –0.162 mm). Thorax (Fig. 3A, B): Maximum thorax width of allotype, 0.230 mm (mean, 0.227 mm; range, 0.225 –0.230 mm). Mesothoracic spiracle diameter of Allotype, 0.017 mm (mean, 0.017; range, 0.016 –0.019). DPTS length of allotype, 0.104 mm (mean, 0.105 mm; range, 0.102 –0.108 mm). Thoracic sternal plate (Fig. 3B) with more rounded margin on posterior extension than male. Abdomen (Fig. 3A, B): Broader than thorax with 19 tergites and 15 sternites. Tergites 1–4 as in male; tergites 5–18 narrow, each with 5–8 long TeAS; last tergite distinctly curved and with 1 short and 2 long setae on each side. Sternites 1 and 2 as in male; sternites 2 and 3 each articulating laterally with corresponding paratergal plate (as characteristic of genus); sternites 3–15 each fairly narrow and with 8–12 StAS. One DMAS on each side lateral to each of tergites 6–18. One VMAS on each side lateral to each of sternites 6–15. Paratergal plates (Figs. 2B, 3A, B): As in male but shape of some individual plates slightly different. Genitalia (Figs. 2D, 3B): Subgenital plate subtriangular but with small indentation on each side that is more obvious in cleared, slide-mounted specimens (Fig. 2D) and posterior extension that tapers to truncate margin in SEM specimens (Fig. 3B); cleared specimens with 2 distinct posteriorly directed rounded projections; patches of spicules evident especially near anterior and medial lateral margins; 3 rows of small to minute setae in central to posterior region of plate, Row 1 with 4–5 setae, Rows 2 and 3 each with 2 setae. Gonopods VIII slightly elongate and medially situated, each with 3 posterior setae, antero-medial seta slightly shorter than other setae. Gonopods IX less distinct and slightly more lateral than gonopods VIII, each with 3 robust apical setae. Taxonomic summary Type host: Alticola barakshin Bannikov, 1947 (Gobi Altai mountain vole) (Museum of Southwestern Biology catalog No. MSB:Mamm: 289112 —symbiotype). Other host: Alticola strelzowi (Kastchenko) (Strelzow’s mountain vole) (MSB:Mamm:289797). Specimens deposited: 1 male holotype (MSB:Para:32437), 1 female allotype (MSB:Para:32438), 2 male paratypes (MSB:Para:32441 and 32442), 2 female paratypes MSB:Para:32439 and 32440), 1 additional male (MSB:Para:32447), 1 additional female (MSB:Para:32443) (all sample no. NK270167) ex A. barakshin symbiotype; 4 additional males (MSB:Para:32445, 32447, 32448, 32450), 3 additional females (MSB:Para:32444, 32445, 32446) ex 3 A. barakshin (sample nos. NK270107, NK270111, NK270120); 1 male ex A. strelzowi (MSB:Para:32449) (sample no. NK270545), Museum of Southwestern Biology, University of New Mexico, Albuquerque, New Mexico. Type locality: (Ex A. barakshin) Mongolia: Bayan Olgii Province, Zoolon (49°54 ′ 17.496 ′′ N, 90°06 ′ 55.296 ′′ E) (holotype male, allotype female, 2 male paratypes, 2 female paratypes, 1 additional male, 1 additional female, 28 July 2015 (sample no. NK270167); collectors: B.-O. Ochirbat, S. E. Greiman, J. A. Cook, B. S. McLean, and N. Batsaikhan. Other localities: Mongolia: Bayan Olgii Province, Zoolon (48°54 ′ 29.448 ′′ N, 90°08 ′ 50.760 ′′ E) ex 3 Alticola barakshin (4 males, 3 females), 27 July 2015 (NK270107, NK270111, NK270120); Huljaa river valley (49°24 ′ 23.940 ′′ N, 89°05 ′ 07.908 ′′ E) ex Alticola strelzowi (1 male), 5 August 2015 (sample no. NK270545); collectors: H. Toman, S. E. Greiman, J. A. Cook, B. S. McLean, and N. Batsaikhan. Site of infestation: Skin surface and fur. ZooBank registration: urn:lsid:zoobank.org:act:97DF00C9-EFA1-4305-838B-E4A96987F8BE. Etymology: The specific epithet is derived from the Altai mountains where the hosts and lice were collected. DNA sequences: See Appendix I., Published as part of Durden, Lance A., Robinson, Chase, Cook, Joseph A., Bell, Kayce C., Nyamsuren, Batsaikhan & Greiman, Stephen E., 2022, Sucking Lice (Phthiraptera: Anoplura) Parasitizing Mongolian Rodents With The Description Of A New Species Of Hoplopleura From Mountain Voles (Alticola Spp.), pp. 353-365 in Journal of Parasitology 108 (4) on pages 355-357, DOI: 10.1645/22-2, http://zenodo.org/record/7756349