Shufeldt : Osteol(~»(;y of the Herodfones. 



17' 



backwards, upwards, and a little outwards. In the Yellow-Crowned 

 NMght Heron these ends are cut squarely across, and are obliquely con- 

 cave. In A. candidissima they are very much as in the Night Herons, 

 though deeper from above downwards, less concave, and face rather 

 more outwardly. Otherwise the mandible of this Heron resembles in 

 every particular the bone as found in the representatives of the genus 

 A)dca. 



As we might expect, it is built upon the same type also, in 

 Nvcficorax, differing in no very essential particular. It is propor- 

 tionately shorter, stouter, and more obtuse ; the ramal vacuity is filled 

 ill here also. 



There seems to be no exception to the rule that all Herons have 

 the glossohyal of the //)w'</ <?/'Md'j- in cartilage, (Fig. 6). Careful ex- 

 amination made with a good lens fails also to disclose to me the 

 slightest trace of osseous tissue deposited in the cartilage of the cerato- 

 hyals of adult specimens of Ardea herodias. This is equally true of 

 ./. candidissima, but in my immature specimen of Nyctcorax I find a 

 distinct, though very small osseous cerato-hyal, on either side, em- 

 l:)edded in the cartilage of the second visceral arch. 





Fig. 8 dis. Right lateral view of the skull of Nycticorax ttycHcorax mrviiis. Nat- 

 ural size, adult; drawn by the author from a specimen collected by Dr. Streets at San 

 iJiego, California, q, quadrate ; /, lacrymal ; mxp, maxillo-palatine ; //, palatine ; pt, 

 pterygoid. 



The first basibranchial is compressed from side to side in the Arde- 

 incE generally, with the posterior aspect of the hinder end fashioned 

 to articulate with the anterior heads of the cerato-branchials, and the 

 head of a slender styliform second basi -branchial of no great length, 

 which rides above them in the median line. Each cerato-branchial is 

 a long delicate rod of bone, in old individuals often attaining a length 

 12 



