LÖNNBERG, THE PELVIC BONES OF SOME CETACEA. 13 



As a rudiment of pubis is to be considered a triangulär 

 process on the right pelvic bone situated aboiit 31 cm. from 

 the end of ala ilii and about 10 cm. from the end of ischium. 

 The width across the whole bone at this process is about 

 42 mm. and the bone is there trigona), but tapers gradually 

 towards the end of the ischium which is compressed. On 

 the left pelvic bone hardly any trace of a pubis can be 

 detected and ischium is compressed in its whole extent. 



As there were no soft parts adherent to the bones when 

 they arrived, it is impossible to say whether this Sperm- 

 whale has had any rudiment of femur or not. If there has 

 been any on the right side where the pubic portion appears 

 to be present it is hardly probable that there could have 

 been any on the left side. 



The pelvic bones now described are very different from 

 those of a Spermwhale from lie de Ré in the museum of 

 Bergen which have been described and figured by Abel 

 (1. c. p. 172—174). 



The greatest difference lies therein that in the latter the 

 pubic portion was very much more strongly developed and 

 there was a real acetabulum for the rather big rudiment of 

 a femur (about 10 X 6 cm.). These pelvic bones were also more 

 strongly curved than the present ones, and in consequence of 

 this their longitudinal extension was only resp. 320 und 327 mm. 



More similar to the pelvic rudimento now described, is 

 that of the left side of a Spermwhale from the southwestern 

 coast of Tasmania originally described by Flower^ and kept 

 in the Museum of the Royal College of Surgeons in London. In 

 this bone the pubic portion is not much more developed than 

 in the specimen from South Georgia, and the bone itself is 

 less curved than those of the Spermwhale from lie de Ré. 



As thus the pelvic rudiments of two Sperm Whales from the 

 Southern seas are alike, it could easily be believed that such 

 simple and little developed pelvic bones were characteristic 

 for the southern animals, if there was no other material 

 known. Such an assumption is, however, ccntradicted by the 

 fact that still less developed rudiments have been found in 

 Cachalots caught off Northern Norway and at the Azores. In 

 these animals therefore the shape and development of the 

 pelvic rudiments cannot be ascribed any taxonomic value. 



^ Träns. Zool. Soc. London 1868. 



