1881.] ON THE GENERIC DIVISIONS OF THE BUCCONIDjE. 775 



EXPLANATION OF PLATE LXVI. 



Fig. 1. Thwaifesia margarififera, sp. n., p. 7G6. 



a, Spider in profile, enlarged, without, legs or palpi ; b, eyes, from 

 in front ; c, maxilliB and labium ; d, left palpus, fiom outer side ; 

 e, right palpus, from outer side ; /, genital opening and process, from 

 in front ; g, ditto in profile ; h, natural length of Spider. 



2. Eriauchenus workmanni, sp. n., p. 768. 



a. Spider in profile, enlai-ged, without legs or palpi ; h, caput in 

 profile, moreeularged ; c, caput and falces, from in front ; f/.uiaxilhe, 

 labium, and sternum ; e, perspective view of caput and falces ; 

 /, Spider, of natural size. 



3. Ariamnes atfenuata, sp. n., p. 770. 



a, Spider, enlarged, in profile, with legs and palpus on one side 

 only ; 6, right palpus, from outer side ; c, caput in profile. 



4. Mutina furcifera, sp. n., p. 771. 



a, Spider enlarged ; b, caput and falces, from in front; c, natural 

 length and breadth of Spider. 



5. Bucranium taurifrons, sp. n., p. 772. 



a, Spider, enlarged ; b, caput, still more enlarged, from above and 

 behind ; c, outline of Spider in profile, enlarged ; d, caput and falces, 

 from in front ; e, maxillK, labium, and sternum ; /, natural length 

 of Spider. 



6. Perissoblemma thomisiforme, .sp. n., p. 774. 



a, Spider, enlarged ; b, ditto, outline in profile ; c, caput, falces, and 

 eyes, from in front; d, caput and eyes, from above and behind; 

 e, maxilla} and labium; /, posterior extremity of abdomen, from 

 above, looking backwards, and showing tiie anal tubercle and trans- 

 verse folds ; g, natural length of Spider. 



6. On the Generic Divisions of the Bucconidse, together with 

 the Description of a new Species of the Genus Nonnula. 

 By P. L. ScLATER, M.A., Ph.D., F.E.S., Secretary to the 

 Society. 



[Eeceived June 17, 1881.] 



As I now shortly hope to complete my Monograph of the Jacamars 

 and Puff-birds by the issue of the sixth and seventh parts of that 

 work, I beg leave to lay before the Society a summary of the generic 

 divisions which I have adopted in the latter family. It will be no- 

 ticed that I have made as few changes as possible in the nomenclature 

 generally used, although I have now found it necessary to distinguish 

 two aberrant and little-known species by new generic names. 



In my ' Synopsis of the Bucconidse, ' published twenty-seven 

 years ago, I divided the family into four genera, as follows : — - 



1. Bucco, Linn., with 15 species. 



2. Malacoptila, G. R. Gray, with 12 „ 



3. Monasa, Vieill., with 4 „ 

 4'. Chelidoptera, Gould, with 2 „ 



Total 33 species. 



In the new illustrated Monograph of the group, which I am now 

 bringing to a completion, the following arrangement of the family 

 into genera has been adopted : — 



