472 DR. R. W. SHTJFELDT ON [NoV. 16, 



discovered during his dissections of the arms of birds ; this was the 

 presence or absence of the expansor secundariorum muscle (Coll. 

 Sci. Papers, p. 32.3). As this delicate muscle and its tendon is 

 well developed in the Storks, he, for convenience sake, termed it 

 the Ciconine character. He found the CuculidtE to be Ciconine 

 birds so far as this structure was concerned, but I find after a very 

 careful search in both pectoral limbs of my specimen of Geococcyx 

 that this character is missing in it. This, then, constitutes another 

 difference between Geococcyx and the Cuculidse. 



Of the Pectoral Muscles. 



All three of the pectoral muscles are present in this bird, and all 

 conspicuously developed, although the pectoralis tertius is consider- 

 ably larger in comparison than is usually the case. Their muscular 

 fibres are remarkable for their fine texture and compactness, both of 

 which qualities, added to their pale colour, lend to these structures 

 a very delicate appearance. 



Nothing of a pecuhar nature seems to distinguish either the 

 pectoralis major or secundus, as they both arise and are inserted in a 

 manner common to the majority of the class. 



On the other hand, the pectoralis tertius, although inserted as 

 we usually find it in birds, has no sternal origin, but arises from the 

 externo-anterior aspect of the sternal extremity of the coracoid, as 

 well as from the side of the shaft of the same bone. 



Recent dissections of mine, performed upon various species of the 

 Corvidse, go to show that in them this muscle has quite an extensive 

 origin upon the sternum, and its bulk sinks into insignificance when 

 compared with the size of the great pectoral as it exists in all of the 

 species of this latter group which I have examined. 



On the Myology of the Pelvic Limb in Geococcyx. 



Quite recently I have completed a very extensive chapter on the 

 muscles of birds, and the MS. of this piece of work, with the 

 nearly one hundred woodcuts that illustrate it, are at hand at tlie 

 present writing. So with the bird now before us I will, without 

 further explanation, adopt the myological nomenclature which I 

 have proposed in my MS., without discussion of sucii points as 

 wherein I may differ in homologies or terms with other authorities. 

 Such differences, and I trust they may be few and well sustained, 

 must be left for decision until such time as the work referred to 

 appears in type. 



It is my aim here to enter quite extensively into the description of 

 the muscles of the pelvic limb of Geococcyx, as they offer us many 

 points of interest. 



We find the sartorius muscle (Plate XLIV. fig. 1, S) powerfully 

 developed in Geococcyx, as are the mnjority of the muscles of the 

 thigh in this bird. It arises, semitendinous, from the crest of tlie 

 neural spine of the last vertebra of the dorsal region of the spine, from 

 the summit of the anterior portion of the crista of the sacrum, and from 

 the adjacent surface of the superior aspect of the ilium on the cor- 



