Mammalia. Cete. i7 



quently assume the form of triangular plates with the outer and fore 

 angle produced into a superorbital process : they are joined to contigu- 

 ous bones by squamous suture. The bone formed by the coalesced Pre- 

 frontals (Phyaeter) penetrates the posterior part of the groove of the 

 vomer, and expands above it, forming the septum of the vertical 

 nasal passage ; it is not complicated with Turhinal or Rhinal capsules, 

 as in the so-called * Ethmoid ' of the other Mammals. The Malar 

 is generally small and slender. The Condyle of the Mandible projects 

 from the posterior part of the base or ascending ramus. In some 

 Cete the Pterygoid processes of the Sphenoid remain separated 

 throughout life. In Delphinus a bony Tentorium is found. In 

 Physeter the capacious basin on the upper surface of the skull, which 

 lodges the valuable produce called * spermaceti,' is formed by the 

 expanded and concave nasal processes of the Prsemaxillaries and 

 Maxillarics which overlap the Frontals. In the mature Balasna 

 mysticetus, the Maxillaries are disposed each like an expanded arch 

 along the outside of the co-extended Praemaxillaries ; their inferior 

 surfaces have two facets, separated by longitudinal ridges, to the sides 

 of which the plates of baleen are attached. 



The Vertebral Column. The discoid terminal Epiphyses long re- 

 tain their individuality, especially in Balaena. There are no Anapo- 

 physes. The Cervical region is short; the Cervical vertebrae are always 

 seven in number, but each is flattened from before backwards into 

 a broad thin plate, and partly anchylosed with its fellow on either 

 side (except in Narwhal in which they are all free), and thus rendered 

 almost incapable of movement on one another : indeed in most of the 

 true "Whales (Balsena), Grampus, and Porpoise, the Cervical vertebrae 

 are blended together into a single bone. In many species of this group 

 the second Cervical vertebra lacks the Odontoid process. The number 

 of Ribs directly articulating with the Sternum is variable. The 

 ITcemapophyses, by which the Pleurapophyses or Eibs are joined to 

 the Sternum, are commonly cartilaginous, rarely osseous. The num- 

 ber of the component bones of the Sternum is also variable. The 

 Sternum of the Whale consists of but one short and broad bone, to 

 which is usually connected a single pair of Eibs. The vertebrae 

 without Eibs succeeding to the Dorsal are many in number, and, 

 since they are as free from anchylosis as in Pishes, cannot be differ- 

 entiated into * lumbar ' and ' sacral.' The Sacrum is never indi- 

 cated hy vertebral confluence^ and only obscurely by the position of the 

 Pelvic rudiments loosely suspended below. The Caudal vertebrae 



