Table 2.

Similarity matrix comparing binary sequences on segments 1–22 (table 1). (Rows and columns ordered to show that sequences for Amphiduros fuscescens (Am), Hesione splendida (He), Nereimyra punctata (Ne), Psamathe fusca (Ps), Sirsoe methanicola (Sm; all Hesionidae) are close to Syllidae (Sy), and both of these are less close to Acoetidae (Ac), Aphroditidae (Ap), Polynoidae (Po) and Sigalionidae (Si). The distance between two binary strings is defined as 2⁻ⁿ if the first instance where the strings differ is in the nth position; the distance between identical strings is 2^−∞=0.)

taxon	Am	He	Ne	Ps/Sm	Sy	Ac/Ap/Po/Si
Am	0	≤2−21	2−20	2−20	2−8	2−5
He		0	2−20	2−20	2−8	2−5
Ne			0	2−23	2−8	2−5
Ps/Sm				0	2−8	2−5
Sy					0	2−5
Ac/Ap/Po/Si						0