In harvestmen the two main body sections ( the abdomen and cephalothorax are broadly joined , so that they appear to be one oval structure ; they also have no venom or silk glands . The difference between harvestmen and spiders is that in harvestmen the two main body sections ( the abdomen with ten segments and cephalothorax , or prosoma and opisthosoma ) are broadly joined , so that they appear to be one oval structure ; they also have no venom or silk glands .