134 A. C. OUDEMANS. ACARI. 



Mandibies (Fig. 74 and 75) short, curved downward, strongly chitinized, anteriorly 

 obliquely eut off, and, seen from above, with distal external blunt small tooth. 



Maxillae. Coxal part (base) ventrally pentangular, with top backward (Fig. 71). The 

 posterior (proximal) part is interior, covered by the skin, and shows a médian epimerite 

 (Figg. 71 and 75). Coxal hairs pectinate, near the trochanterofemur of the palp (Figg. 71 and 75). 

 Hypostome (Fig. 71) triangular; its distal part ventrally swollen (Fig. 75); this swollen portion 

 has a heart-shaped ventral aspect (Figg. 71 and 74), for the top of the hypostome is bilobate. 

 Dorsally (Fig. 73) the hypostome is distally open and bears basally a pair of smooth hairs, 

 reaching beyond the top. Tliere is no trace of an epipharynx, nor of a liypopliarynx. Troch- 

 anterofemur of palp dorsally and externally swollen, dorsally with a feathered hair. Genu 

 dorsally (Fig. 73) and internally with a smooth hair. Tibiotarsus dorsally with two smooth 

 hairs, ventrally (Fig. 74) with a proximal and external strongly curved pectinate hair, intern- 

 ally with a strong distally pectinate hair and terminally with a strong bifid claw (the main 

 claw being provided ventrally and externally with a secondary smaller sharp accessory claw). 

 Telotarsus very short, scarcely club-shaped, with four feathered hairs and two smooth olfac- 

 toric hairs. 



Legs (Fig. 70). Legs II are the shortest ; legs III the longest. Ail the femora are distinctly 

 divided in a basifemur and a telofemur. The joints of each leg are increasing in length dis- 

 talward. The number of the beautifully pectinate hairs on the joints increase distalward. Notic- 

 eable are the following facts : The tarsi I and II both show an indistinct protarsus (Figg. y6 

 and yy). The tibiae I and II are distally provided (Figg. 76 and yy) with a short rod-like 

 olfactoric hair. Tarsus I is proximally provided with a rod-like olfactoric hair and in its distal 

 half with a second sharply-ending ditto. Tarsus II (Fig. yy) shows in the middle a short rod- 

 like olfactoric hair, standing on a short rounded protubérance. Tarsus III (Fig. 78) is proxim- 

 ally provided with a long smooth hair, apparently tactile. Ail the paratarsi are distinct, at least 

 twice longer than wide, distally provided with two curve, slender, blunt claws, and with a 

 claw-like empodium, slenderer and longer than the real claws and scarcely proximally and 

 distally nodded. 



Habitat: on the head op Goura sp., where hundreds are placed in regular rows like 

 the pavement in the street, and apparently cause featherless spots. Remarkable is the fact 

 that Professors SaraSIN hâve caught the saine species on the legs of themselves and of a 

 Javanese in North-Celebes, where thèse mites cause the same itch like the larva of Tlirom- 

 bidium van der Sandei Oudms. in the woods and forests of New Guinea. 



Remark. This larva is called „gonone" in North-Celebes. But since the name „gonone" 

 appears in Littérature, it has got the signification of itch-causing-creature on the legs, so that no w 

 in New Guinea the name „gonone" is also attributed to the larva of Thrombidium van der Sandei. 



Named in honour of Prof. Dr. A. WlCHMANN, leader of the Expédition. 



Erythraeus de Beauforti Oudms. 

 (Plate IV, fig. 79—87). 



1905 March 1. Erythraeus de Beauforti nov. sp. OUDEMANS in Entomologische Berichten, 

 n°. 22, p. 217. 



