754 MR. F, 0. PICKARD CAMBRIDGE ON [June 16, 
lati.” ‘Tibis quatuor antice inferne aculeis setiformibus 3—3, 
metatarsi aculeis validioribus 3—3 instructi, pedes postici nume- 
rose aculeati.”’ ‘ Mamille fusco annulatex.” “ Long. ceph.+abd. 
13°5 mm.” 
There is very little doubt, short of actual comparison of types, 
as to the identity of H. auricomis, Sim., with my female adult 
specimen from Santarem and with the immature females from 
Gurupa. The males have not hitherto been described, but the two 
obtained on the Lower Amazons undoubtedly belong to the females 
taken at the same time. 
Genus Dretura, C. Koch; E. Sim. 
Type. Mygale macrura, C. K. (dg. 65 mm. long), Die Arach- 
niden, ix. p. 38, tab. ece. fig. 715 (1842). Hab. San Juan, West 
Indies. In coll. Impr. Mus. Berlin. 
The genus Diplura was founded in 1850, ‘Uebersicht des 
Arachn.,” C. L. Koch, p. 75. The author says of the type, 
D. macrura, ‘Sehr gerade ausstehende Spinnwarzen,” and in his 
description of the same spider under Mygale he says “ Kopf und 
Thorax rostgelb”—‘‘ Der Hinterleib sammt den Spinnwarzen 
braunschwarz.” 
The figure on plate ccc. seems to suggest that this species is 
closely allied to that described below as D. sanguinea, but the 
unicolorous abdomen would prove it to be certainly a different 
species. Not having seen the type of the genus, which apparently 
is still extant in Berlin, and feeling pretty sure that it will prove 
not congeneric with the three species described below, I have con- 
sidered it less liable to lead to confusion in the future to form two 
new genera for their reception. Two of them, Melodeus sanguineus 
and M. niger, might possibly fall under Simon’s group A, while the 
third, Harmonicon rufescens, would fall under group B (ef. Hist. Nat. 
Ar. i. p. 178, 1892). If, however, group A really corresponds, as 
M. Simon suggests, to Bertkau’s genus Thalerothele, then mine will 
not fall into the group, for of Th. fasciata, Bert., the type of the 
genus, Bertkau says “scopula nulla”; whereas all these three species 
possess very distinct scopulz on the tarsi of all four pairs of legs. 
It is just possible, however, that Bertkau’s type may be immature, 
in that case the scopula would probably not be developed ; but of 
this I cannot speak with certainty. 
Trechona' is undoubtedly a good genus, the tarsi and protarsi 
1 Genus Trucuona, OC. Koch. 
Type. Trechona zebrata (Walck.), 1835, sub Mygale (Q). In coll. Brit. 
Mus. Nat. Hist. 1896. 
Anterior eyes almost equal, forming a slightly curved line, almost straight. 
Carapace a little raised behind the eye-tumulus. Posterior spinners one-half 
shorter than abdomen; segments subequal. Legs long, robust; protarsi and 
tarsi i. and ii. entirely and densely scopulate, the former with three or four 
long spines lying amongst the scopuls; the latter without any central series of 
long setze amidst the scopule. Protarsus iii. with distal two-thirds, tarsus iii. 
entirely, densely scopulate. Protarsus iv, with distal half and entire tarsus iy. 
