18/6.] ANATOMY OF CHAUNA DERBIANA. 197 



Screamer more Closely approaches. It evidently does not share the 



EnT'V^ '^' ^'JT'' "^ ^" ^P^"^^ «f -hich the surface of 

 origui for the pair of large extensor muscles of the mandible is 



aboTin" { ^of^P/essed from side to side, and elongated from 



abole f.7r' ' '* '^' '"T '''''' '^'''' '^''' •« the pair of openings 

 above the foramen magnum (figs. 1, 2, 3, p. 198) 



sk.^lf T; ^'°'" ^^°™P^"f " of the inferior surfaces of the same three 

 max lllf ^'l"^ y,^^.'dent that in the Screamer the pr«.maxillEe. 



" r^Jrt' SdTn fig"?!"^' "^' outspreading. The palate of CAauna 

 .nJll ''^''" l"'!'"'^i the skull is, no doubt, as in the Anseres, desmo- 

 buf this';! ".-^ '^-^ "'^-'JS-P^l^tines united across the middle line ; 

 the two t I' "v snfficently important to compel us to unite 



^WeorJ ^^! • "•■ '* '"''• ""''' '^'' ''''' '' ^°"ld be- necessary to 

 give credence to an association of birds which is in other respits 



TotZl""T''^- Jr '^': Capitonida., for instance. MeffalJnai 

 not desmognathous. whilst Tetragonops is so. 



As before stated in the Anserine birds the lachrymal re-ion is 

 specially long This is least marked in the CereopI Goollicere- 

 cms nov^.holandice), where, however, it is clearly apparent In 



tl'eTeS It^rte?'"^^ ^^^^^" ^^ '' '^^^ ^ ^ ^^«^^""- "^ ^ 



iJl ^"^^ f^^ ^^"'^'■^' ^"^ ^^"'°* the pterygoid bones have lar-e 

 faceted surfaces for articulation with the basisphenoid rostrum. I.' 

 both groups these facets are situated very far forwards-quite at the 

 anterior ends of the bones in the latter / in Ckauna, however the e 

 amculations are quite independent of the anterior ends of tl 'bon ' 



fSmoieS "" "^ " '"^"''' "' '^' '"^'^^^^ °*' '^''^' «'herwise 

 As to the quadrate bones, their cranial articulations are bifid 

 winch IS the case in all birds except StrutAio, RAea ZmLfs' 



They do to a certain extent resemble the sam'e bones in the W^ 



ly bSd thet'f "f ?;''"^ 'V"' j'^-^^^ ^-h- situated so 

 way behind the level of their mandibular articulations (not a Galli- 

 naceous character), which latter they also resemble in conSgurat o 

 the usual y extended outer facet not running backwards and'inward ' 

 as in most birds but not in the Gallinte "iwarus 



tion is mn?h'l'"''' '!ii" *^- ' ^7P^""' '^'' Pterygo-quadrate articula, 

 this ;; n" t theTare! '''° " °''" '''"''''' «^" ^^« '^-- '^ ^^-- 



In C/5a««a the angle of the mandible is much prolonged and un 

 curved, as in the Anseres, from which it however differs fn not bebg 

 deeply excavated in the interval between the upturned process ad 

 he inwardly-directed articular angle. It must be remembered that 

 the mandible is much the same in the Galling 



It must also be remembered that the Screamers are the onlv 



