TRANSACTIONS OF THE SECTIONS. 67 
but one true molar to each side of each jaw, as in others of the group to which it be- 
longs. On the ocher hand we find a considerable approach evinced in the genus 
Gymnura (one of the Insectivora) to the carnivorous order, displayed in the general 
form of the skull, in the presence of six incisors (a number unusual in the Insee- 
tivora), and well-developed canines. Here is a case of one of the Insectivora ap-~ 
proaching the Carnivora on the one hand, and of one of the Carnivora approaching the 
Insectivora on the other. But the two animals mentioned do not approach towards 
each other in corresponding modifications of structure. Several other illustrations of 
this point are noticed in the paper, which then proceeds to give some general obser= 
vations on dentition, and characters derivable from other parts, with a view to show 
the kind of connexion which exists between the several genera introduced in the 
table, and the orders to which they are approximated. In none of the instances of 
approach of species of one order to other orders alluded to in the paper, does the 
author perceive a case which would, in his opinion, fully bear out the notion that the 
orders imperceptibly blend into each other. There is always (he observes) a tolerably 
well-marked line between them, hence he has inclosed the orders in circles. The 
aberrant species are readily traced back, as it were, into their own groups, and when 
they evince an approach to other circles, it is rather to the order, than to any par- 
ticular species of the order. 
In conclusion, he offers the following propositions and observations for conside= 
ration :— 
Species of animals belonging to the same genus have an affinity to each other; 
genera of the same family have a mutual affinity; relationship of affinity may like- 
wise exist between families of the same order, and orders of the same class, but the 
degree of affinity is different in the different cases. Thus, 
species of the same genus have an affinity of the first, or nearest degree ; 
species of different genera have an affinity of the second degree only ; 
species of different families have an affinity of the third degree only ; 
species of different orders have an affinity of the fourth degree only ; 
species of different classes have an affinity of the fifth degree only. 
_ Arelationship may exist between species of different groups which differs from 
either of the cases just mentioned,—that which is commonly termed by naturalists a 
** relationship of analogy.” This again may vary in degree according to the affinities 
and relative rank of the groups which present the cases of analogy. The analogy may 
be more or less remote. Thus the case of analogy (so often quoted as such) as ex- 
isting between the Goat-sucker (Caprimulgus) and the Bat—members of different 
classes—might be expressed as one—say of the fifth degree; that of the Otters to 
the Beavers (animals of different orders of the same class) an analogy of the fourth de- 
gvee ; and that of the Beaver to the Coypu* (Myopotamus), an analogy of the third 
degree. Again, the relationship existing between the Whales and Fishes may be one 
of analogy of the fifth degree, that existing between the Dugong and the Porpoise 
may be one of affinity or analogy, but in either case is less remote than the relation- 
ship of the Cetacea to the fishes. 
According to these propositions, moreover, the relaticnship of the Lagostomus to 
the Marsupiata might be one of affinity of the fourth degree, whilst that of the Wom- 
bat to the Rodentia might be one of analogy of the same degree; that of the Wombat 
to the Phalangistide, an affinity of the third degree ; and of the Koalu (Phascolomys) 
to Phalangista, an affinity of the second degree; and lastly, that of Phalangista vul- 
pina to Phalangista Cookii, an affinity of the nearest, or first degree. The affinity of 
the Monotremata to the class Reptilia would be several degrees further removed than 
that of the Echidna to the Ornithorhynchust. 
‘On the Physical Character, Languages, and Manners of the People of the 
Navigators Islands. By Mr. Hearn. 
_ The islanders were described as a fine race of people, the average size rather above 
that of Europeans—the colour brunette, the face oval, the hair black and rather crisp, 
_ * These two animals are essentially modelled upon different types of the Rodent order. 
__ + The Monotremuta are placed with the Edentata by Cuvier, but Mr. Waterhouse regards the 
Monotremata as constituting an aberrant group of the Marsupiata: their relationship with the 
true Edentata is certainly one of analogy only. 
F2 
