718 ‘MR. F. 0. PICKARD CAMBRIDGE ON [June 16, 
so common in the neighbourhood of Santarem, yet not once could 
I detect a Spider in the act of seizing her prey or even venturing 
beyond the entrance of her burrow. 
I accentuate these deficiencies in our information, because one 
so otten hears of a traveller neglecting to collect material, or make 
observations of habits, on the grounds that the “ Authorities ” at 
home nowadays know everything and that the trouble taken would 
be but labour lost. 
Among the more interesting incidental discoveries made during 
the work of classification, I might mention that of the stridulating-= 
organs found in three species of the subfamily Diplurine. These— 
to which I have given the names lyra and pecten (the former 
referring to a row of chitinous keys on the inner side of the coxa 
of the pedipalp, the latter to a row of spines on the mandible)— 
are very similar to the musical boxes found in certain Oriental 
groups of Mygalomorphe by Mr. Pocock. Of what may be their 
real use, and of what their ultimate significance in systems of 
classification, it is perhaps a little too soon to speak. 
Before concluding these few remarks by way of preface to the 
more technical and less interesting descriptive matter, I would like 
to take the opportunity of giving my hearty thanks to the many 
kind friends from whom I received both encouragement and actual 
assistance during our expedition up the Amazons. 
Had it not been for the courtesy of Mr. and Mrs. Alexander 
Siemens, I should probably not have visited Brazil at all. Nor 
must I forget to thank Mr. Brocklehurst, of Para, through whose 
kind introduction I fell into the hands of Mr. Wallace, an American 
gentleman resident in Santarem. For my fortnight’s excursion 
in the forest I am entirely indebted to Mr. Wallace, who 
courteously placed his country residence at my disposal and 
gave me every assistance in his power to render my sojourn a 
complete success. 
To the many other friends whom I came across both afloat and 
ashore, too numerous to mention by name, I must give my thanks 
en masse. 
Bibliography relating to the Theraphoside of South America. 
1726. Madame Mur1an.—Insect. Surinam. 
1746. Kiermann.—Rosel’s Insects. 
1758. Linnaus.—Syst. Nat. ed. 10. 
1764. Linnmcs.—Mus. Ludovice Ulrice. 
1820. Durour.—Ann. Sci. Phys. Nat. 
1830-1844, M. Purry.—Delectus Animalium Articul. que in 
itinere per Brasiliam coll. J. B. de Spix et C. F. Ph. de Martius. 
1831-1848. C. W. Haun and C. L. Kocu.—Die Arachniden. 
Niirnberg. 
1838. Guférin.—Reyv. Zool. p. 10. 
1850-1862. H. Lucas.—Expédition scientifique dans l’Amérique 
du Sud Centrale, de Rio 4 Lima et de Lima a Pard. 
