256 MR. W. K. PARKER ON THE SKULL [Feb. 15, 



lescentibus : caudce parte basali in rectricibus externis rubri- 

 cante : alarum et caudtB pagina inferiore flavicante : long, 

 tota 16-0, alee 8-7, caudm rectr. med. 9'5, lat. 4-5. 

 Hab. Peruvia alta, in leg. sylvatica orieiitali, ab incolis Loro real 

 dicta (Tschudi). 



Mus. Novo-Castellano. 



Obs. Species ab Ara muracana rostro majore, genis solum nudis, 

 area postoculari plumosa, et corporis colore rubro nullo certissime 

 diversa, et Ludovico Coulon, Musei Novo-Castellaui Directori optimo, 

 dicata. 



Dr. T. S. Cobbold, F.R.S., exhibited and made remarks on a 

 Parasite (Echinorhi/nckus) obtained from the Tamandua Ant-eater 

 which had died in the Society's Menagerie, and had been described 

 in his communication made at the last meeting. 



Mr. W. K. Parker read the second part of his memoir on ^Egi- 

 thognathous Birds *', of which the following is an abstract : — 



In my former communication I described thirty-one examples of 

 this kind of palatal structure in birds ; in the present paper I have 

 added fifty-one more. 



Altoo-ether these eighty-two birds belong to thirty-nine " fami- 

 lies;" so that I have taken, on an average, two examples of each 

 family. The materials for this research have been kindly and 

 liberally put into my hands by a number of friends, among whom I 

 may mention Frotessors Alfred Newton, T. Rupert Jones, and 

 Garrod, Dr. Murie, Osbert Salvin, Esq., Robert Swinhoe, Esq., 

 Mr. W. J. WiUiams, and Mr. Bartlett. 



I began my last paper with a bird showing " iEgithoguathism " 

 in its initial state. 1 end this communication with another instance: 

 the first was Turnix, this is Thinocorus — both of the utmost 

 importance to anyone seeking for the true passerine /jAy/w/^. 



Now if any one will say that because I have found initial iEgi- 

 thognathism in birds so far down below the most degraded (or 

 rather non-elevated) type of Passerines, as these birds, that there- 

 fore I, putting these types in the .(Egithognathous hst, seek to 

 make them appear as " Coracomorphse," such a one has failed 

 to catch my drift. Do we modern biologists believe in the gradual 

 modification of types or evolution of species, or do we not? If 

 we do, we shall i easonably expect to find that our neatly trimmed 

 and highly special types must have had grosser and more general 

 ancestors in the Tertiary period. Allowing this supposition, and 

 looking upon birds as a hot-blooded group whose root lay low 

 down, once, among the cold blooded reptiles, shall we not expect to 

 find birds more or less related to the modern types having the 

 nature of several at once? — "all these in their pregnant causes 



mixed." 



In the examples given in this second part I have shown pecu- 



* For pnvt I. see Traus. Zool. Soc. ix. p. 289. 



