DR. F. LEUTHNER ON THE ODONTOLABINI. 483 
easily accounted for, as these were already islands’, at least in part, at the same period. 
Thus these small species, which are far inferior to their continental allies in size, must 
be regarded as antiquated forms. 
In like manner the original home of the species of Odontolabis must be sought for in 
Further India. 
O. carinatus, which occurs in Ceylon and on the east coast of India, is certainly of 
Malayan origin. It is difficult to determine whether it has migrated from the south by 
some previous land-communication or from the north; but Wallace has shown that 
several of the mammals, birds, and reptiles of Ceylon are likewise of Malayan origin’. 
The species which occur on the other islands show no exceptional distribution; for 
although many of them are peculiar species, yet they are closely connected with others 
found either on the continent or on the large adjacent islands. But although the 
Philippines are nearer to the Chinese coast, their species show a greater affinity to 
those of the Sunda Islands than to those of Formosa. 
Lastly, the two species of the genus Heterochthes are confined to Siam and to the 
Andaman Islands respectively. 
As the accompanying Table will show, species occurring in the same locality are 
generally so dissimilar that their interbreeding is quite impossible, and it is not 
unlikely that they may arrive at maturity at different seasons, in which case they would 
be still less likely to interfere with each other. 
For example, the following species are met with in the peninsula of Malacca:— 
1. Neolucanus cingulatus, Parry; 2. Odontolabis striatus, Deyr.; 3. O. wratus, Hope; 
4. O. wollastoni, Parry; 5. O. gazella, Fabr.; 6. O. latipennis, Hope. 
In Sumatra we find:—1. NV. lansbergii, Leuthn.; 2. O. castelnaudi, Parry; 3. O. som- 
meri, Parry; 4. O. latipennis, Hope; 5. O. wollastoni, Parry ; 6. O. ludekingi, Vollenh. ; 
7. O. lacordairii, Vollenh.; 8. O. gazella, Fabr.; 9. O. dalmani, Hope. 
But when closely allied species occur in the same locality, intermediate forms (or 
hybrids?) are of frequent occurrence, which circumstance renders the species difficult 
to separate (comp. pp. 412-414). 
A comparison of the number of species will give the clearest idea of the important 
part migration and isolation have played in their differentiation. 
1 Comp. K. Martin: “ Die wichtigsten Daten unserer geologischen Kenntniss vom Niederlindisch Indischen 
Archipel” (Tijdschrift van het Koninklijk Instituut yoor de Taal-, Land- en Volkenkunde van Nederlandsch 
Indié, 1883). 
2 Wallace, Geographical Distribution of Animals, vol. i. p. 327. 
442 
