Explanation of a passage from Gauss's writings on knot theory.

Question

Gauss's writings on knot theory include five lists of knots (see Geometria Situs - Gauss's werke: volume 8, p.282-285: http://gdz.sub.uni-goettingen.de/pdfcache/PPN236010751/PPN236010751___LOG_0082.pdf): the first for knots with one cross (with only one knot on the list), the second for knots with two crossings (with three knots on the list),the third for knots with three crossings (with 15 knots on the list) the fourth for knots with four crossings (with 105 knots on the list), but the fifth list is with unclear meaning (it contains 120 knots and it has no title). I guess Gauss made these tables as a first step toward knot tabulation, but i'm not sure about it; in particular i want to know whether the lists he made for each number of crossings are complete, what's the meaning of the six drawings on page 284, and what's the idea behind the fifth list.