Issued in nine parts in temporary board covers with title labels; each part with series t.-p. (Ray society) and special t.-p.; the first five parts (part I; part I cont'd; part II; vol. II, pt. I, and vol. II, pt. II) under title: A monograph of the British annelids. New general title-pages with the changed title were issued for vol. I and II with the second part of vol. III. For detailed collation of the parts as issued cf. the printed statement at end of vol. IV, pt. II (p. [539]) I. Nemertinea and Polychæta: Amphinomidæ to Sigalionidæ. 1873-1900.--II. Polychæta; Nephthydidæ to Ariciidæ. 1908-10.--III. Polychæta: Opheliidæ to Ammocharidæ. 1915.--IV. Polychæta: Hermellidæ to Serpulidæ, with additions to the British marine Polychæta during the publication of the monograph. 1922-23