Mr. W. K. Parker on Pterocles, Syrrhaptes, and Tinamus. 307 



" In the first place, let me at once say that they have no right to 

 the dignity of the gallinaceous title ; they are little struthious birds, 

 looking upwards from that simple rudimentary beginning of the 

 beautiful ornithic type. 



" Nearly all the specialization of this bird, by which it rises above 

 the Struthionidce, is in the direction of the true or typical gallina- 

 ceous bird, and not towards the Ptarmigans, as is the case of the 

 Sand-Grouse. 



" The Hemipodius runs upwards towards the little flat-bodied 

 typical Quails ; but there is no bird better for comparison with the 

 Tinamou than the common Hen. Nine-tenths of the characters of 

 the bony structures of the head in this bird are truly struthious : 

 the residuum belonging half to the Plover and half to the Fowl. 



" It is not a little curious, however, that it outdoes the Plover in 

 one thing, viz. the structure of the supraorbital region ; for whilst 

 the nasal or supraorbital glands in the Pluvialince are protected by 

 a continuous beam of bone, the Tinamou has the unique character 

 of a series of those bones. In the young Ring-Dottrel I find a series 

 of square denticles growing out from the margin of the frontal below, 

 and external to the large gland ; these exogenous processes fuse 

 together in the adult. 



" I had racked my memory to find an instance of multiplied supra- 

 orbitals in a vertebrate skull, but in vain, when one turned up to 

 me on examining the Reptilian skeletons in the Museum of the Col- 

 lege of Surgeons, a few months ago : this example is the skull of the 

 Trigonal Cayman. 



" There are three on each side in this latter creature, united by a 

 triradiate suture ; in the Tinamou, however, there are six or seven 

 larger and several smaller ossicles on each side. At first sight it 

 seems as though half the sclerotic ring had been attached there by 

 accident ; these supraorbitals are, however, much stronger than the 

 sclerotals. 



'* The sternum of the Tinamou is greatly differentiated when com- 

 pared with that of a Rhea or Emeu ; but all the improvement is 

 gallinaceous. It is absolutely the most unique and wonderful of all 

 the sternums I have seen, the variations of which in the bird-class, 

 as is well known, are very great and very exquisite. 



" The presence of a somewhat deep keel, so seemingly fatal to the 

 struthious theory of this bird's relationship, strange to say, turns out 

 a good proof of its validity and truth. Every one who has watched 

 the larger-winged Ostriches must have noticed their habit of lifting 

 their wings — a motion performed by the middle pectoral muscles or 

 levatores of the humerus : to these muscles nearly all the keel of the 

 Tinamou' s sternum is devoted, a most narrow, small corner being 

 left for the thin abortive depressores — muscles which, not only in 

 typical birds, but also in the heavy Gallinacese, are of very large size. 

 The small ' furculum ' is Pluvialine ; but the coracoids and scapulas 

 come very near to those of the common Fowl. 



" The blending of the last cervical with three out of four of the 

 dorsal vertebrae is gallinaceous , but the absence of costal appendages, 



