LÖNNBERG, THE PELVTC BONES OF SOME CETACEA. 



V 



at the R. Nat. Hist. Museum in Stockholm. It was the com- 

 plete skeleton of an adult male measuring about 14, i o m. 

 and SöRLiNG had in accordance with his orders taken great 

 pains in securing the rudimentary pelvic bones which he 

 found to be situated 4 m. 23 cm. from the end of the ta il 

 measured in a straight line. -. , 



The shape of these pelvic rudi- 

 ments is seen from the accompanying 

 figures (fig. 1). The ossified parts 

 consist not only of the pelvis, but there 

 is also a large rudiment of the femur, 

 and in addition to these ossified parts 

 also pieces of cartilaginous and fibrous 

 tissue as will be described below. 



The ilium is best developed. 'It is 

 stout, towards the pubis it is almost 

 trihedral but towards the free end more 

 cylindrical and thicker. The ischium 

 is shorter and more slender, the right 

 is compressed, the left almost cylindri- 

 cal. The pubis is comparatively small, 

 triangulär in outline but very thick. 

 The iHum and the ischium are not si- 

 tuated in a straight line but the slen- 

 derer ischium appears to be curved 

 inwards towards the median line (fig. 2). 



The distance from the tip of the 

 ilium to the tip of the ischium is on 

 the left side about 34 cm. when only 

 the ossified parts are counted, and on 

 the right side the same measurement 

 is about 38 cm. The bony parts are 



quite truncate but at both ends fibrocartilaginous bodies are 

 adherent (conf. fig. 1). The diameters of the thick end of 

 the ilium is on the left side about 4 7^ and 3^2 cm., on the 

 right side both dimensions are about Vs cm. less. The width 

 across the pubic portion of the pelvis is about 7 ^j-i cm. and 

 the thickness about 3\/2 cm. 



The length of the femur is between 17 and 18 cm. It 

 is very much broader at the distal end (6 Vs cm.) than at the 

 proximal end (conf. fig. 1) (about 4 cm.) but narrowest (3 cm.) 



Fig. 2. The right pelvic 



Ijone of Balfena anstralis 



from below. 



