6 



W. LlLLJEBORG, 



this intention into effect, his indefatigable scientific activity was for ever 

 interrupted by his untimely death, to the great loss both of his science and 

 his friends. It is to be regretted that the work he had planned has not, 

 since Prof. Eschrichts' death, been completed by his worthy colleague in 

 the treatise on the Northern Whale. 



Dr. W. H. Flower's treatise on the whale-skeletons in the Dutch 

 and Belgic Museums, while evidencing the comparative anatomists experienced 

 eye and accurate perception of characteristic distinctions, has the merit of ma- 

 king us better acquainted with the interesting whale-skeletons preserved in 

 the two countries above named, which offer types of new genera and new 

 species. It contains also some valuable remarks on the importance of the osteo- 

 logical characteristics, with respect both to individual variations and those 

 which are the result of age. 



Before proceeding to a description of the bones of the two whales 

 that form the subject of this essay, we will give a short account of the as 

 yet known geuera belonging to the suborder of the Whalebone Whales, in 

 order to show in what relation the genera, to which the specimens in que- 

 stion belong, stand to the other. In this we consider that we ought chiefly 

 to follow the arrangement adopted by Prof. Gray in the above mentioned 

 work, with the exclusion of a few genera, which seem to us to rest partly 

 on very slender partly on insufficient characteristics. 



Mysticete, Gray, 

 or Whalebone Whales. 

 Dorsal fin 



Families: 



present 1. Balaenopteridae, Gray. 



absent 2. Balaenidae, Gray. 



Balaenopte- 

 ridae. 



Bladebone 

 with processus 

 coraeoideus and 

 acromion .... 



complete and 

 large. Pro- 

 cess, coronoi- 

 deus 



high and di- 

 stinct. 1 st 

 pair of ribs 

 at upper end. 



Genera: 



undivided. (60 or more 1. Physalus, Gray. 



Number of | 

 vertebrae 



cloven or 

 biceps. Of 

 the cervi- 

 cal verte- 

 brae . . . . 



(50 or less 2. Balaenoptera, Lace'p. 



only epistropheus with 

 annular lateral proces- 

 ses 3. Flowerius, n. gen. 



epistropheus and nea- 

 rest adjacent with an- 



Jnular lateral processes 4. Sibbaldius, Gray. 



low, forming merely a tubercle 5. Eschrichtius, Gray. 



rudimentary or none 6. Megaptera, Gray. 



