•^IS _ MB. F. o.;PicKAnD OAMBRiDOB ON [June 1 6, 



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 often liears of a traveller neglecting to collect material, or make 

 observations of habits, on the grounds that the " Authorities " at 

 home nowadays know everytldiuj 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 Diplurince. These — 

 to which I have given the names lyra and }>ecten (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 Mygalomorphce 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 spealc. 



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 botli afloat and 

 ashore, too numerous to mention by name, 1 must give my thanks 

 tn masse. 



Bibliography relating to the Theraphosidas of South America, 



1726. Madame Meeian. — Insect. Surinam. 



1746. Kleemann. — IJosel's Insects. 



1758. LinnjEds. — Syst. Nat. ed. 10. 



1764. LiNNTEUs. — Mus. Ludovieae Ulrica). 



1820. DufOUR.— Ann. Sci. Phys. Nat. 



1830-1844. M. Peety. — Delectus Animalium Articul. quas in 



itinere per BrasiJiam coll. J. B. de Spix et 0. F. Ph. de Martius. 

 1831-1848. 0. W. Hahn and 0. L. Kooii.— Die Arachniden. 



Niirnberg. 

 1838. GtJKEiN.— Eev. Zool. p. 10. 

 1850-1862. H. Lucas. — Expedition scientifique dans I'Amerique 



du Sud Centrale, de Eio h. Lima et de Lima a Para. 



