Map of the mitochondrial genomes of Gononemertes parasita and Nemertopsis tetraclitophila. Genes coded on the coding strand are arranged clockwise; those on the other strand are counter-clockwise. Thirteen protein-coding genes are shown in blue and two ribosomal RNA genes in pink. Transfer RNA genes are labeled by their single letter of corresponding amino acids. Major non-coding regions (mNCR) are represented in grey.