BY G. F. FERPTS. 285 



Notes. This species is extremely close to 0. strigilecula 

 Ferris from South America. T have compared the specimens 

 directly with the type of tlie latter species and the only really 

 significant differences that I have fonnd are as follows. The 

 antennae in 0. soror are noticeably l^hmter tlian in the other, 

 the processes of the mesostermmi sharper and longer, the setae 

 of the abdomen noticeably more iiuineioiis and more slender. 

 When more is known as to the distribution of these forms it 

 may very well prove that they should merely be regarded as 

 sub-species of the same thing. 



Ornithoctona magna n. sp. (Plate 11, fig. e--h.) 



Specimens Examined. Ten females and three males from 

 the Kalabit district on Spilopelia tigrina. Holotype, a female, 

 paratype females and one paratype male returned to the 

 Sarawak Museum. Remainder retained in the Stanford 

 Collection. 



Female. Length on slide 12 mm. ; length of head and 

 thorax, 6 mm. In alcoholic specimens the head and thorax 

 above are very dark brown except for the frontal vitta of the 

 head and the humeral regions of the thorax which are pale ; 

 entire underside of head and thorax pale and legs pale at base 

 of femur ; remainder of legs almost black ; abdomen grey. 



In general characters very closelv approaching the preceding 

 species, the description and figure of chaetotaxy of head and 

 thorax applying almost equally well to either. There is a 

 slight tendency toward a greater number of setae than in 0. 

 soror, the scutellum of 0. magna bearing as many as eight 

 long setae instead of four. 



Antennae (Plate 11, fig. 2r/> noticeably more slender and 

 more constricted toward the apex than in 0. soror. Thorax 

 with the anterior processes of the mesostenum (fig. 2^?) 

 short and broad. Legs with a pronounced lamellate process 

 at the apex of the anterior tibiae (fig. 2/) which is absent 

 in 0. soror. 



Abdomen entirely devoid of chitinous plates, except for the 

 basal plate both dorsally and ventrally as in 0. soror; 

 completely covered, except for the apical region, with small 

 setae which are set on minute, chitinous prominences ; position 

 of the paired apical plates in 0. soror marked by a cluster of 

 3—5 long setae. Ventral side with long setae surrounding the 

 genital region as in 0. .soror. 



