The “original” Snail Shell labyrinth was created from the seed pattern for Ariadne’s thread. To do that only the first curve to be drawn had to be shifted one “unity” to the right. Then all points were connected with each other. Thus a new type for a 7 circuit labyrinth appeared.
However, this type can also be derived from the well-known seed pattern for the walls. The construction goes as usual, only that everything is shifted to the right.
The following drawing shows the walls in black, the seed pattern is highlighted in color.
In the meantime, Andreas has also posted something to this labyrinth. He has explained the pattern in the labyrinth, and has pointed to the fact that the path crosses twice the axis. Thus, in the terminology of Tony Phillips it is a non-alternating uninteresting Labyrinth.
The “pattern” is for Andreas not the seed pattern, but the structure of the labyrinth, as best to be seen in the rectangular form. Hence, “uninteresting” in the terminology of Tony Phillips means that inside this labyrinth the type Knossos is hidden to which only some circuits are added. And the fact that one enters the labyrinth on the first circuit and reaches the middle from the last one.
For me it is interesting that developing the Snail Shell labyrinth from the seed pattern produces the cruising axes. This is ordinarily not the case when using this method. Nevertheless, a new type of labyrinth appears.
If one constructs a labyrinth by only using the path sequence, and without cruising the axes, one will get another labyrinth again. Thus it looks:
This is quite an other type of labyrinth, although it has the same path sequence. Moreover, it is self-dual, because you may count the circuits from inside outwards and you will get the same path sequence.
This shows once more that only the path sequence is not sufficient to classify the type. Unfortunately, I must say, because this makes the categorization even more difficult and more complicated.
One receives even more variations if one includes the crossing of axes or chooses other forms (circle, square). Of which more later.