Octogomphus specularis female exuvium Ophiogomphus colubrinus female Ophiogomphus colubrinus female exuvium Ophiogomphus colubrinus male exuvium Ophiogomphus occidentis exuvium Ophiogomphus occidentis female Ophiogomphus occidentis male Ophiogomphus severus exuvium Ophiogomphus severus female Ophiogomphus severus male Phaenogomphus graslinellus female Phaenogomphus graslinellus male