THE SPERM WHALES, GIANT AND PYGMY. 731 
Maxillaries (m) continuous, the Maxillaries differentiated into 
contour bei mply interrupted wW ortion the dee e- 
by the anteorbital tch; the ante- orbital notch; the eren Short, 
rior portion very long, high, wide, low, nd ecarinate; the 
narrow, 
and carinate at its proximal half; posterior portion imi a thickened 
the posterior panna simply decliv- external contour. 
ous on the frontals. 
Intermaxillaries (i) very elon- Intermaxillaries very short, di- 
gate, nearly contiguous "S verging forwards on account of the 
and projecting forwards sider- development of the vomer; not or 
ably beyond the nostis. ittle extending beyond the maxil- 
laries. 
Lower jaw with the symphysis Lower jaw with the symphysis 
the 
Vie co-equal with the alveolar iis more than half as long as 
region, and more Nr. half the alveolar region, and less than a 
Teen of the rami. third the length of the rami. 
5. Deductions Respecting the Relative Value of Differ- 
ences. Thus have we in considerable detail contrasted the 
respective peculiarities of the two groups of Physeterids. 
e have gone into such detail, as it is only in that way that 
we can appreciate the great difference between the two. 
The question now arises, pees is the value of those groups? 
Are they simply genera? or are they entitled to higher rank? 
On account of the limited number of species, and the close 
relationship of the several members of the respective groups, 
we are compelled to judge somewhat by analogy, and com- 
parison with allied families. As the result of such compar- 
isons, especially among the representatives of the families 
Ziphiids and Delphinids, it is believed that the value of 
Several characters above given is of more than generic value, 
the difference appearing to be very much greater than exists 
between genera in either of those families, and it is there- 
* Our readers E in Boston and its suburbs ean verify t the ch yseter by a 
visit to the Museu at Cambridge which establishment 
are the skull and wake of the skeleton of an individual obteiaed, | we believe, on the coast of 
New Jerse 
4M t may be. remarked here that [Mae oes remains from the Mintene « a m3 sre United 
* crocodilinus Cope, and Ontocetus Emmonsii Leidy; and some from the gobaemequ as Phy- 
seter antiquus Leidy. 
