nervous system, [12], [22];

body-wall, [13];

muscles, vascular system, [15];

haemocoele, [22], [23];

body-cavity, [16], [22];

nephridia, [16], [17], [22];

reproductive organs, [18];

development, [10], [19], [20], [22];

species, [23];

distribution, [24]-[26]