Monodontium malkini, Raven, 2008

Raven, Robert J., 2008, A Revision Of The Mygalomorph Spider Genus Monodontium Kulczynski (Barychelidae: Araneae), Raffles Bulletin of Zoology 56 (1), pp. 29-44 : 35-37

Monodontium malkini , new species

( Figs. 1 , 4A–G ; Table 2)

Monodontium sp. : Raven, 1994: 319, 322, Figs. 16B, 19E.

Material examined. – Holotype. “Hollandia [=Djajapura, West Papua, 2º32'S 140º42'E], Dutch New Guinea ”, female, Apr.1945, Borys Malkin ( AMNH).

Diagnosis. – Females differ from those of M. mutabile in the absence of the outer row of teeth on the claws of leg IV and from M. tetrathela in the absence of the posterior median spinnerets. Spermathecae: two, each a narrow twisted duct.

Etymology. – Named in honour of the collector, Borys Malkin.

Description. – Holotype female (AMNH): Carapace 3.13 long, 2.38 wide. Abdomen 3.42 long, 2.28 wide. Total length, 7.0.

Colour in alcohol: Carapace orange-brown with brown marks on caput and along margin, chelicerae, maxillae, labium, and sternum orange, legs orange-brown with distinct brown annulations proximally on all tibiae to about one-third their length. Abdomen dorsally brown with eight small, irregular, paired areas in posterior half, laterally with small white mottling; ventrally pallid with three long irregular brown areas between posterior booklungs and two irregularly shaped areas in front of the spinnerets.

Carapace: Pilosity: almost glabrous; striae indistinct, narrow; no bristles dorsally on caput save for few anteromedially; 2 bristles between PME, and 5 long between ALE; long between AME, long brown bristles on lateral margins. Fovea straight; one pair of foveal bristles. Clypeus absent.

Eyes: Tubercle distinct. In three rows (2.2.4); back row procurved. Eye group occupies 0.29 of head-width; front width, back width, length, 23, 23, 19, respectively. MOQ front width, back width, length, 13, 16, 9, respectively. AME:ALE:PME:PLE, 4: 8: 4: 5. Eye interspaces: AME– AME, 0.5; AME–ALE, 1.3; ALE–PLE, 2.0; PME–PME, 2.5; ALE–ALE, 2.0.

Chelicerae: With narrow band of spaced thin brown bristles prodorsally, laterally with few fine hairs. Rastellum of 2–3 long curved spines on inner edge and 6 thinner in transverse line laterally. Furrow promargin with 3 thick close teeth anteriorly and 4 smaller spaced teeth posteriorly teeth, basomesally with curved line of 10–15 fine red teeth.

THE RAFFLES BULLETIN OF ZOOLOGY 2008

Labium: 0.28 long, 0.63 wide. One cuspule present; labiosternal suture narrow.

Maxillae: 0.88 long in front, 1.28 long behind, 0.58 wide; with 16–17 cuspules in inner angle. Heel rounded; anterior lobe indistinct.

Sternum: 2.08 long, 1.53 wide. Sigilla small, oval, marginal.

Legs: Coxae I, II with slightly pronounced heel.

Scopula: Metatarsi: I, II, distal thin, divided widely; absent on III, IV. Tarsi: palp, I, II, thin, sparse, widely divided by band 6–8 setae wide; absent on III, IV.

Spines: Leg 1: fe p1d3; pa 0; ti 0; me v2. Leg 2: fe p1d3; pa 0; ti v1; me v2. Leg 3: fe 0; pa p2r1; ti p1r1v8; me p3r2v8. Leg 4: fe r1; pa 0; ti r2v8; me p3r2v10. Palp: fe 0; pa 0; ti v3.

Claws: Three to four teeth on paired claws of legs I–III in two rows; 3 teeth on prolateral faces on IV, none on other face; three teeth on inner face of palpal claw. Claw tufts thin, narrow, terminating well below curve of claws.

Trichobothria: In two rows on tibiae, each of 5–7 for half length; about 6 on metatarsi in diagonal line; about 8–10 filiform but none clavate on tarsi.

Spermathecae: Two, each a narrow twisted duct.

Spinnerets: PMS absent. Basal, middle, apical, total segments of PLS, 0.43, 0.15, 0.10, 0.68 long, respectively.

Male: Unknown.

Distribution. – Djajapura, north-east West Papua.

Remarks. – The tarsal organ and claw tufts of Monodontium sp. ( Raven, 1994: Figs. 19E and 16B, respectively) are those of M. malkini .

Figures

Fig. 1. Occurrence of Monodontium.

Fig. 4. Monodontium malkini, new species, holotype female: A, cephalothorax, dorsal view; B, eyes, dorsal view; C, sternum, maxillae, labium and chelicerae; D, abdomen, dorsal view; E, spermathecae; F, spinnerets, showing apical segment of PLS; G, abdomen, ventral view. Scale bars = 1 mm for A, C, D, G; 0.5 mm for B, F; 0.25 mm for E.