344 ZOOLOGICAL GEOGRAPHY. [part hi. 



abundant and characteristic. Out of the 41 Oriental genera 21 

 are Malayan, and 10 of these are not found in the other sub- 

 regions. 



In Lucanidae the Malay islands are rich, 14 out of the 16 

 Oriental genera occurring there, and 3 being peculiar. There 

 are many fine species of Odontolabris, which may be considered 

 the characteristic genus of the sub-region. 



The Cetoniidae are well represented by 16 genera and about 120 

 species. The genera Mycteristes, Phccdimus, Plectrone, Euremina, 

 Rhagopteryx and Ccntrognathus are peculiar, while Agestrata, 

 Ghalcothca, and Macronota are abundant and characteristic. 



The Longicorns, as in all continental forest regions near the 

 equator, are very abundant and in endlessly varied forms. No 

 less than 55 genera containing about 200 species are peculiar to 

 this sub-region, the Cerarnbycidse being much the most numerous. 

 Euryarthrum, Coelosterna, Ayelasta, and Astathes may be consi- 

 dered as most characteristic ; but to name the curious and in- 

 teresting forms would be to give a list of half the genera. For 

 the relations of the Longicorns of the Indo-Malay, and those of 

 the Austro-Malay region, the reader is referred to the chaptef on 

 the distribution of insects in the succeeding part of this work. 



Terrestrial Mollusca. — The Philippine islands are celebrated 

 as being one of the richest parts of the world for land shells, 

 about 400 species being known. The other islands of the sub- 

 region are far less rich, not more than about 100 species having 

 yet been described from the whole of them. Helix and Buli- 

 mus both abound in species in the Philippines, whereas the 

 latter genus is very scarce in Borneo and Java. Ten genera of 

 Helicidse inhabit the sub-region ; Pfeifferia is found in the 

 Philippines and Moluccas, while the large genus Cochlostyla is 

 almost peculiar to the Philippines. Of the Operculata there are 

 representatives of 20 genera, of which Dermatoma and Pupi- 

 nella are peculiar, while Registoma and Callia extend to the 

 Australian region. Cycloplwrus, Leptopoma, and Pupina are 

 perhaps the most characteristic genera. 



