
WoMERSLEY—MICROTROMBIDIINAE OF AUSTRALIA AND NEW GUINEA 295 
amity TROMBIDIIDAE Leach 1814. 
Susvamity MICROTROMBIDIINAE Sig Thor, 13a (dan. ). 
= Orronunag Sig Thor, 1934, Nov. (1935). 
Kmended Description. 
Body size small to moderate. Shape more or less cordate, often with well de- 
fined shoulders to hysterosoma, propodosoma usually triangular, its base slizhtly 
narrower than hysterosoma, latter slightly tapering with rounded posterior, A 
distinct suture line between propodosoma and bysterosoma, Crista linear, with- 
out avy enlarged triangular or subtriangular anterior area or nasus!, with u 
rowidish subposterior areola-like sensillary area furnished with a pair of long 
filamentous sensillae. yes usually present. 2--2, on well developed sessile or sub- 
sessile ocular shields. Palpi generally stout, tibia with stout apical claw, smaller 
accessory claw, two pectines and usually 1 ov more strong spines on external side ; 
tarsus usually elongate. Dorsal setae very variable, simple, or spine-like, pennate, 
clavate, septate or of eurious forms, often of two distinet sizes or Forms. 
Genotype: Microtrombium G. Haller, 1882. 
Kev ro tae Genera (ADULT) OF THE MicrorROMBIDIINAR SIG THOR 1935, 
1. Legs T and TV very much longer than the body, 1 much stouter than the others. Shoulders 
prominent, Eyes 2-+ 3, sessile, Palpal tibia fairly slender in divtul portion, with #trong 
apical claw, with or without smaller accessory claw, with pectines but without external spines. 
Dorsal sotuc, more or less pennate or with long setules, of uniform or variable lengtli 
Dromeolhrombinm Bert, 1912. 
2, 
Legs Land LY not, or only slightly longer than the body 
2. With two kinds of dorsal setae, of which the longer are stiff? and a spines, ‘ath or without 
short setules or serrations = .. sf 
tf with two kinds or lengths of dorsal setae then the longer ones re ¢ not stiff'and spinu-like 4, 
3. The smaller dorsal setae pennate, or ath? with Jong ciliations, Palpul tibia with one strong 
external spine + Echinothrombinm Wom. 1937. 
Smaller dorsal setae spalhulate, with tong erilations or short denticles. Crista, posterior of 
sensillary avea evancacent. TPalpal tibin without external spine = Spathiutathranbium nov. 
4. Dorsal setae, even if of two different longtlis, peanite, or as slender rods with long ciliations 
Microtrombidium Haller 1882 4. ett. 
Dorsal setae of varying forms but not as above rr : be ois) MG: 
5. At least the larger dorsal setae septate and chambered ‘z rt ov «6, 
No dorsal setae septate = a. L4 ‘it 7 
6, Dorsal setae uniform, slender, clavate, aeptete, and decumbently curved 
Campylat hrombium Krause 1916, 
Larger dovsal setac globose or thistlotike, septate, upright and not curved or decumbent; 
smaller setae variable at .. Camerotrambidinm Sig Thor 1936, 
7. Dorsal setae mainly ewisea: and tightly packed, but with some fine simple louger vetar 
interspersed : . ve Butrichothrambium Wom, 1937, 
Dorsal setae other Wise ofe AY 4 * &. 
&. Dorsal setac small, uniform, tree-like with fine intertingling bvabtipe: Palpal tibin witli 
external spine rp i fe ola i Ai ch Sig Thor 1936, 
Dorsal setae otherwise Ie “ ' 9, 
9, Dorsal setae thin and Jametiate, or oad Like, often with the margins Spuleprtel aaniabiaid 
80 muuch so as to form a sort of helmet ae me vs ots oe 40, 
Dorsal setae otherwige we — sae ay ig, 
1. Dorsal setae with the margins not. jingeoed: foliate .- ow AL: 
Dorsal! sctac with the margins more or less ineurved, sometimes atrongly 80; (he setae being 
helmet-like ‘ 2 “4 obs = Totsotrombidium noy. 

1 The anterior rounded. or sinuated apex of the propodosoma may he a more or lese lightly 
chitimized transvorse plate appearimg as part of the evista as in 2 cchidninum but there is no 
true unteriorly projecting nagus. 
