THE WHALEBONE WHALES OF THE WESTERN NORTH ATLANTIC. 



SIBBALDIUS TECTIROSTRIS COPE. (TYPE.) (Continued.) 



87 



Measurement. 



Transverse extent of centrum do. [3d cervical] i i.o 



Length parapophysis sixth cervical 5.0 



Vertical diameter centrum (sth ?) dorsal 7.0 



Length centrum do 6.0 



Vertical diameter centrum second caudal, with perforate dia- 



pophyses 10.5 



Length of centrum do 10.5 



Height, spine and arch, middle lumbosacral 145 



from floor canal to top anterior zygapophysis 6.0 



Scapula, antero-posterior width 33.0 



vertical width 21.0 



Length of acromion 7.5 



: ' coracoid 4.5 



Diameter of glenoid cavity 8.0 



Length of cranium (axial) 1 26 in.' 



Greatest width of occipitals 43 o 



Width at supraorbital plate 5 2.0 



of each maxillary at middle 9.75 



of supraorbitals above orbit 13.0 



(least) of frontal region 13.5 



of nasals 4.3 



intermaxillaries at middle 5.3 



Length, nasal 6.0 



maxillary above 90.0 



ramus mandibuli (in curve) 1 20.0 



to coronoid 19.0 



Depth at condyle 8.5 



, at coronoid 13.0 



at middle 9.0 



Length, otic bulla 5.2 



Length of longest plates of whalebone with gum 15.0 



Width do. at base. . 10.0 



Cope's 



measurements, 

 1869. 



My 



measurements, 

 1899. 



II. O 



33- 



20.0 



8.0 



n 



8.5 



121. 



52-5 



9-75 ' 

 12. * 



14.0 



6.25' 



4-33 



6-75 

 90.0 



120.0 



9-5 



It is, I think, proper to assume that the type of /S. tectirostris is nothing more 

 or less than a specimen of the "common Finback" of the Atlantic coast of the 

 United States. Cope, at the time of original publication, was probably not in posses- 

 sion of the fact that the Finback which strands most frequently on our coast is of the 

 fashion of B.physalus (L.). He considered his specimen most closely allied to Sib- 

 baldius laticeps of Gray (= B. borealis Lesson), but, as might be expected, he found 

 numerous differences. At a later date, in consequence of his own more extended 

 studies, and the progress of cetology, he perceived that tectirostris was properly to 

 be associated with, or might even be identical with, B. physalus. Cope also con- 

 sidered his 8. tuberosus allied to 8. laticeps of Gray and for a time identified it with 

 the latter species. But at the same time he pointed out two external characters 

 by which he supposed it differed from tectirostris, the form of the dorsal fin 



'Not re-measured by myself. * Cope gives 120 in. on another page. 



1 If the nasal process of the maxilla is taken into account ; otherwise, 9 in. 

 4 This is the greatest breadth ; the least is 8.75 in. 



6 This is the width at the distal end. Cope's measurement was probably taken at the proximal 

 end, for which it is correct. ' The coracoid is broken. 



