4/0 PROF, HUXLEY ON THE CLASSIFICATION OF BIRDS. [Apr. 11, 



This immense group of birds corresponds in great part with the 

 Passeres of Linnaeus and Cuvier, and wholly with the Volucres 

 of Sundevall, who thus defines it : — 



Alarum tectrices breves. Pollex validus solus retroversus. Ungues 

 compressi. 



AlcB pennis cubiti magnis tectricibusque parvis instructce ; tec- 

 trices cubitales minorem quam dimidiam pennarum partem te- 

 gunt. Margo alee plicatce non a pennis cubiti obtegitur ; 

 prima enim earum ad ultimam remigum applicata manet. Di- 

 giti semper 4. Pollex crassior vel longior semper volumine 

 major quam digitus internus. Unguis pollicis semper mulfo 

 major quain laterales sed in quibusdam non major quam medius. 

 Digitus externus toto articulo prima cum digito medio concre- 

 tus. Phalanx digitorum penultima reliquis multo longior; 

 basales (iu digito externa et medio) breves. Cutis pedum firma , 

 arete applicata, antice scutata. Tarsus scutis 7 : mediis Ion- 

 gioribus, 2 injimis brevissimis superioribus et inferioribus oppo- 

 sita vice obliquis* ; raro plumatus, nunquam reticulatus. In- 

 terdum scuta omnia prceter 2 injima in unum levissimum, suturis 

 obsoletis conjluunt {tarsi caligati, lUiger). Digiti scutis pha- 

 languni 1 seu 2 longis, juncturarum brevibus. Apparatus 

 musicus laryngis his avibus peculiaris. 



The Volucres thus defined are divided into two "orders," as 

 follows : — 



Ordo I. Passeres. Rostrum crassius conicum capite brevius. 

 Maxilla inferior marginibus validis injlexis convergentibus pos- 

 tice altioribus. 

 Rostrum a cranio paullo deflexum exit sutura vix longiore quam 

 dorso rostri. Hinc limes faciei rectus apparet, nee ut in se- 

 quentibus ad fauces longe retarsum angulatus. Maxilla inferior 

 ad semina frangenda constructa, ut nuper descriptum qua con- 

 formatione in rostra hiante fauces dejiexce apparent. Lingua 

 parva subcrassa plei'umque caret margine membranaceo. RiC' 

 tus mediocris. Pedes minores graciles. 



Ordo II. OsciNES. Rostrum varium marginibus maxilla inferioris 

 simplicibus nee inflexis. 

 Ordo polymorphus et specierum ditissimus cujus descriptio gene- 

 falis adhucfere tantum negativa existit. 



Now the " Passeres " of Sundevall have all, so far as I have exa- 

 mined them, that peculiar form of the palatine bones which I have 

 described as characteristic of the Finches; while the "Oscines" 

 have the typical vilgithognathous arrangement. And, thus far, cra- 

 nial characters appear to bear out the classification of Sundevall, 

 though I neither think that the groups have the value he assigns to 

 them, nor that their names are happily selected. It is quite impos- 



* Scuta iu PtilonorJiyncho, paucis Myotheris, Coracina et Chasmorhyncho 9. 

 In quibusdam inter longilingues majores 8 parallela, sequalia. 



