Material examined: Holotype: adult (NZAC, in alcohol, 82/7), New Zealand: ND, Hen & Chickens Is. Lady Alice Island, Main Ridge above Grave Bay, from litter, 1 Jan. 1982, leg. R. Hay. Paratype: one adult (NIGA, in alcohol, 82/7), same data as holotype.

Etymology. Named after the type locality—the Lady Alice Island. Motu Muka is the Māori name for the Lady Alice Island, which is a large one (also known as the Big Chicken) among the Hen & Chicken Islands. It is here used as a noun in apposition.

Description. Measurements. Holotype: Prodorsum: length 240, width 155, height 95, setae: ss38, ro 33, in 85; notogaster: length 428, width 270, height 287; setae: c₁ 78, d₁ 70, e₁ 75, h₁ 70, ps₁ 63; ventral region: ad₁ 90, ad₂ 98, ad₃ 19, an₁ 45, an₂ 48; genito-aggenital plate 100×102, ano-adanal plate 80×175. Paratype: Prodorsum: length 250, width 160, height 97; notogaster: length 435, width 275, height 290.

Integument. Colour yellowish. Surface of body covered with small and rounded foveoles with some distances between them.

Prodorsum (Figs. 1–2). Median crista and posterior furrows absent; lateral carinae reachingsinus; sigillar fields distinct, dorsal field narrow, longer than lateral fields; sensilli (ss) with narrow stalk, and fusiform head, covered with small spines; interlamellar setae (in) long, erect and stout, densely covered with small spines in distal half; rostral setae (ro) rough and semi-erect, much thinner than interlamellar setae; lamellar (le) and exobothridial (ex) setae vestigial; comparative length:in>ss>ro; mutual distance of setae: in-in/ro-ro=4.

Notogaster (Fig. 1). 15 pairs of setae (c₁/c₁-d₁=0.78) present, similar in shape with interlamellar setae; setae h₃ shortest and thinnest; setae c₁ and c₃ near anterior border, setae c₂ much further; vestigial setae f₁ positioned posterior to setae h₁; three pairs of lyrifissures ia, im and ih present.

Gnathosoma (Figs. 4–6). Subcapitulum normal (Fig. 4); setae h, m, and a simple and smooth; setae h shorter than distance between them; adoral setae typical of family; palp (Fig. 5) 4-segmented, with femur and genu fused; palpal setation: 0-2-2-7(1); supracoxal seta simple and smooth; chelicera (Fig. 6) typical of family.

Ano-genital region (Figs. 1, 3). Genital setae (g) with formula: 5: 4; ano-adanal plates each with five pairs of rough setae (an and ad), setae ad₁ and ad₂ long, thick and hooked distally, setae an₁ and an₂ thinner but straight, setae ad₃ shortest and thinnest, but distinctly longer and thicker than genital setae; comparative length: ad₂>ad₁>an₂>an₁>ad₃.

Legs (Figs. 7–8). Setal counts for leg segments (without tarsi): I: 1-4-2(2)-4(1); II: 1-3-2(1)-3(1), III: 2-2-1(1)-2(1), IV: 2-1-1-2(1); chaetotaxy of legs complete; setae d on femora I inserted at level of setae l″; setae a” on tarsi I and setae ft” on tarsi II curved distally; setae a” on tarsi II curved distally; setae s and pv′ on tarsi IV present; setae s on tarsi I and II present.

Remark. This new species is more close to Notophthiracarus repostus Niedbała, 1989 in sharing the following features: posterior furrows of prodorsum absent, similar shape of sensilli, interlamellar and notogastral setae, lamellar and exobothridial setae vestigial, vestigial setae f₁ positioned posterior to setae h₁, formula of genital setae: 5: 4, similar shape of setae ad₂ and ad₃, and chaetotaxy of legs complete. However, the new species can be easily distinguished from the latter species by the following eight characters (a versus b): in N. motumuka sp. nov., (1a) lateral carinae of prodorsum present; (2a) dorsal field of prodorsum not bifurcate at distal end, lateral fields longer; (3a) rostral setae relatively short (ro 33), in-in/ro-ro=4; (4a) three pairs of lyrifissures ia, im and ipspresent; (5a) h<h-h; (6a) setae ps4 situated at the level between setae ad₁ and ad₂; (7a) setae ad₁ similar as ad₂, long, thick and hooked distally; (8a) setae d of femora I not bifurcate distally; in N. repostus, (1b) lateral carinae of prodorsum absent; (2b) dorsal field of prodorsum bifurcate at distal end, , lateral fields shorter; (3b) rostral setae fairly long (ro 66), in-in/ro-ro≈1.39; (4b) two pairs of lyrifissures ia and im present; (5b) h>h-h; (6b) setae p_s 4 situated at the level between setae ad₂ and ad3; (7b) setae ad₁ thinner and much shorter than ad₂, slightly hooked distally; (8b) setae d of femora I bifurcate distally.

Material examined: Holotype: adult (NZAC, in alcohol, 83/166), New Zealand: AK, Tamaki Estuary Tohuna Torea, from litter, 13 Oct. 1983, leg. D. Russell. Paratypes: two adults (NZAC, in alcohol, 83/166), same data as holotype; two adults (NIGA, in alcohol, 83/166), same data as holotype.

Etymology. Named after type locality. It is here used as a noun in apposition.

Description. Measurements. Holotype: Prodorsum: length 330, width 210, height 124, setae: ss50, ro 13, in 20, le 13, ex 23; notogaster: length 750, width 375, height 435; setae: c₁ 13, d₁ 15, e₁ 23, h₁ 18, ps₁ 15; ventral region: ad₁ 12, an₁ 11, g₁ 10; genito-aggenital plate 150×195, ano-adanal plate 105×200. Paratypes: Prodorsum: length 232–380, width 178–230, height 104–170; notogaster: length 510–858, width 305–440, height 370–550.

Integument. Colour brown. Surface of notogaster with distinct polygonal sculpture, other regions covered with very small and rounded foveoles with some distances between them.

Prodorsum (Figs. 9, 11–12). Median crista developed; posterior furrows present; lateral carinae absent; sigillar fields distinct, dorsal field narrow and bifurcate anteriorly, longer than lateral fields; sensilli (ss) short and fusiform, covered with small spines; other prodorsal setae (in, le, ro, ex) minute and smooth; comparative length: ss>ex>in>le=ro; mutual distance of setae: in-in/ro-ro≈2.4.

Notogaster (Fig. 9–10). Anterior cowl distinct, covered posterior part of prodorsum, not reaching interlamellar setae; one dorsal, longitudinal carinae present, starting from anterior margin and ending at the insertion levels between setae d₁ and e1; it widens anteriorly and gradually narrows to an thick line at insertion level of setae d₁, then slightly broad posteriorly; 15 pairs of minute setae (c₁<1/10c₁-d₁) present, similar in shape with prodorsal setae; setae c₁ close to anterior border, setae c₂-3 much more remote than c₁; vestigial setae f₁ positioned anterior to setae h₁; two pairs of lyrifissures ia and im present.

Gnathosoma (Figs. 15–17). Subcapitulum normal (Fig. 15); setae h, m, and a simple and smooth; setae h more than two times longer than distance between them; adoral setae typical of family; palp (Fig. 16) 4-segmented, with femur and genu fused; palpal setation: 0-2-2-7(1); supracoxal seta simple and smooth; chelicera (Fig. 17) typical of family.

Ano-genital region (Figs. 9, 13–14). Genital setae (g) with formula: 5: 4; ano-adanal plates each with five pairs of minute and fine setae (an and ad).

Legs (Figs. 18–19). Setal counts for leg segments (without tarsi): I: 1-4-2(2)-4(1); II: 1-3-2(1)-3(1), III: 2-2-1(1)-2(1), IV: 2-1-1-2(1); chaetotaxy of legs complete; setae d on femora I inserted at level anterior to setae l″; setae a” on tarsi I and setae ft” on tarsi II curved distally; setae a” on tarsi II curved distally; setae s and pv′ on tarsi IV present; setae s on tarsi I and II present.

Remark. This new species is most similar to Notophthiracarus tripartitus Niedbała, 1989 in sharing the following features: notogaster with anterior cowl and dorsal carinae; median crista of prodorsum present; posterior furrows present; lateral carinae absent; dorsal field of prodorsum bi-furcate distally; prodorsal, notogastral, anal and adanal setae short and fine; two pairs of lyrifissures present; setae h much longer than distance between them; formula of genital setae: 5: 4; chaetotaxy of legs complete. However, the new species can be easily distinguished from the latter species by the following five characters (a versus b): in N. tamaki sp. nov., (1a) surface of notogaster with distinct polygonal sculpture; (2a) sensilli short and fusiform; (3a) anterior cowl not concave in dorsal view, and small, not reaching interlamellar setae; (4a) notogaster with one short dorsal carina, not same in width longitudinally; (5a) vestigial setae f₁ positioned anterior to setae h₁; in N. tripartitus, (1b) surface of notogaster foveolate; (2b) sensilli long and lanceolate; (3b) anterior cowl concave in dorsal view, and large, reaching far beyond interlamellar setae; (4b) notogaster with two long dorsal carinae, nearly same in width longitudinally; (5b) vestigial setae f₁ positioned posterior to setae h₁.

Material examined: Holotype: adult (NZAC, in alcohol, 72/227), New Zealand: Red I. Mercury Is. CL., from litter, 24 Nov. 1972, leg. G. W. Ramsay. Paratypes: four adults (NZAC, in alcohol, 72/227), same data as holotype; three adults (NIGA, in alcohol, 72/227), same data as holotype.

Etymology. The specific name (rimi) is abbreviation for Red Island, Mercury Islands. It is used here as a noun in apposition.

Description. Measurements. Holotype: Prodorsum: length 255, width 175, height 95, setae: ss35, ro 48, in 75, le 10, ex 15; notogaster: length 504, width 320, height 310; setae: c₁ 80, d₁ 70, e175, h₁ 72, ps₁ 70, ps₄ 46; ventral region: ad₁ 50, ad₂ 70, ad₃ 15, an₁ 45, an₂ 45; genito-aggenital plate 102×150, ano-adanal plate 95×178. Paratypes: Prodorsum: length 205–225, width 150–155, height 75–80; notogaster: length 370–375, width 255–257, height 245–255.

Integument. Colour yellowish. Surface of body covered with very small and rounded foveoles, especially dense on notogaster.

Prodorsum (Figs. 20–22). Median crista, lateral carinae and posterior furrows absent; sigillar fields distinct, dorsal field narrow, longer than lateral fields; sensilli (ss) with narrow stalk, and rounded and rough head; interlamellar setae (in) long, erect and stout, sparsely covered with small spines in distal half; rostral setae (ro) rough and semi-erect, much thinner than interlamellar setae; lamellar (le) and exobothridial (ex) setae short and fine; comparative length: in>ro>ss>ex>le; in/le7.5; mutual distance of setae: in-in/ro-ro≈3.73.

Notogaster (Fig. 20). 15 pairs of setae (c₁/c₁-d₁=0.68) present, similar in shape with interlamellar setae; setae e₂, h₂ and h₃ shortest; setae c₁ and c₃ near anterior border, setae c₂ much further; vestigial setae f₁ positioned anterior to setae h₁; two pairs of lyrifissures ia and im present.

Gnathosoma (Figs. 25–27). Subcapitulum normal (Fig. 25); setae h, m, and a simple and smooth; setae h shorter than distance between them; adoral setae typical of family; palp (Fig. 26) 4-segmented, with femur and genu fused; palpal setation: 0-2-2-7(1); supracoxal seta simple and smooth; chelicera (Fig. 27) typical of family.

Ano-genital region (Figs. 20, 23–24). Genital setae (g) with formula: 5: 4; ano-adanal plates each with five pairs of setae (an and ad), setae ad₁ and ad₂ long, thick, rough and slightly hooked, setae ad₃ minute and fine, setae an₁ and an₂ thinner and straight, setae ad₃ short and fine, similar in shape as genital setae; comparative length: ad₂>ad₁>an₁=an₂>ad₃.

Legs (Figs. 28–29). Setal counts for leg segments (without tarsi): I: 1-4-2(2)-4(1); II: 1-3-2(1)-3(1), III: 2-2-1(1)-2(1), IV: 2-1-1-2(1); chaetotaxy of legs complete; setae d on femora I inserted in the middle of article and slightly posterior to the level of setae l″; setae a” on tarsi I and setae ft” on tarsi II curved distally; setae a” on tarsi II curved distally; setae s and pv′ on tarsi IV present; setae son tarsi I and II present.

Remark. This new species is very close to Notophthiracarus claviger Niedbała, 1993 in having the following features: lateral carinae absent, similar shape of prodorsal and notogastral setae, h<h-h, setae ad3 short and fine, and chaetotaxy of legs complete. However, the new species can be easily distinguished from the latter species by the following six characters (a versus b): in N. rimi sp. nov., (1a) notogaster elongated oval in shape; (2a) sigillar fields distinct, dorsal field narrower; (3a) setae h₁ inserted below level of e₂, setae ps₁ situated much below level of h₂, and setae ps₂ situated slightly below level of ps₃; (4a) formula of genital setae: 5: 4; (5a) setae ad₂ situated slightly posterior to the insertion level of an₁; (6a) setae d on femora I inserted slightly posterior to the level of setae l″; in N. claviger, (1b) notogaster rounded in shape; (2b) sigillar fields poorly visible, dorsal field broader; (3b) setae h₁ inserted slightly above level of e₂, setae ps₁ situated slightly above level of h₂, and setae ps₂ situated slightly above level of ps₃; (4b) formula of genital setae: 6: 3; (5b) setae ad₂ situated slightly posterior to the insertion level of an₂; (6b) setae d on femora I inserted much posterior to the level of setae l″.