Shufeldt: Birds from Bermuda. 375 



longitudinal line. This is separated from the small, flattened " manu- 

 brium " beyond it by the rather capacious coracoidal grooves, which 

 latter are continuous at the median point, and carried around laterally, 

 on either side, to the middle of the base of the coracoid process. 



Carina has a thickened anterior border, which is longitudinally 

 grooved down its anterior face, below which the " carinal angle " 

 projects with great prominence (fig. 32). This keel, too, is carried 

 the entire length of the sternum to the ultimate point in the middle 

 line of the mid-xiphoidal process. On the whole it is deep and of 

 triangular outline, with slightly thickened free margin below. The 

 convex ventral surface is smooth, all to the usual raised lines found 

 there indicating the divisional areas for the pectoral muscles. 



Distally, the xiphoidal margin is twice-notched upon either side, 

 the "notches" being profound and broad, giving rise to a mid- 

 xiphoidal process, with a lateral one and an intermediary one upon 

 either side. 



This sternum has an average width of 2.8 cms. by a length of 4.3 

 cms., the former being taken on a transverse line adjoining the middle 

 points of the costal borders, and the latter from the middle point of 

 the anterior border to the posterior extremity of the keel. It will be 

 observed that this sternum is quite a different appearing bone from 

 that of a typical Shearwater, for example, such a form as we see in 

 figs. 126 and 127 of Plates XXIX and^XXX.^^ 



On the plates already cited above I give a number of figures of 

 the fiirciilum, coracoids, and scapulae of this extinct bird. The former 

 is seen to be of the usual U-form of bone found in Petrels generally. 

 The clavicular limbs are much bowed to the front, while the hypo- 

 cleidium may be said to be aborted below. Above its usual site, ante- 

 riorly, an excavation appears, while behind it, on the posterior median 



15 Since describing above the skeleton there shown, I have received the 

 following letter in regard to it, dated December 4, 19 15, at the Museum of 

 Comparative Zoology, Cambridge, Mass.. and addressed to myself : 



"Dear Sir: I duly received the Shearwater skeleton loaned you for study. 

 It came without any injury whatsoever. I asked our Mr. Bangs to compare 

 the skeleton with skins in the collection, and he identifies the skeleton as 

 Puffinus assimilis without doubt, and probably the subspecies gavia. 



Yours truly, 



Samuel Henshaw, 



Director." 



ANN. CAR. MUS., XIII. 25, FEB. 21, 1922. 



