Best classification is a solid core. A rather ghostly one. It has no spaced bands at the core, so not a divided. The color is thin due to limited frit pickup in that particular area, likely near the end of the cane.
It is a tri-level solid core. A nice one. Keeping the bands consistent when the cane has been worked down to 1/2" is a reflection of real skill. Cane cut marbles were made in Germany (and later, in England) from around 1860 - 1920.
Its a very simple design to make. The technique is called "raking". Looks like they blew off annealing, but thats common when they are in a hurry. Its not really a pontil. Its a small diameter glass rod attachment.