Colobinae is a subfamily of the Old World monkey family that includes 58 species in 10 genera, including the skunk-like black-and-white colobus, the large-nosed Proboscis Monkey, and the gray langurs, sacred to India. Some classifications split the colobine monkeys into two tribes, while others split them into three groups. Both classifications put the two African genera Colobus and Piliocolobus in one group; the two genera are distinct in that they have a stub thumb. The various Asian genera are placed into another one or two groups. Analysis of mtDNA confirms that the Asian species form two distinct groups, one of langurs and the other of the "odd-nosed" species, but suggests that the gray langurs are not closely related to either (Sterner et al., 2006).