558 F. W. GAMBLE AND J. H. ASHWORTH. 



fibrillfie. Nllm. Neurilemma sheath. N. L. V. Nephridial longitudinal 

 vessel. Nm. Neuropodium. Nm. Ch. Neuropodial crotchets. N. N. Nuclei 

 of nerve-cells. N. o.'-'^' Nephridiopores. Notm. Notopodium. Not. S. 

 Notopodial setse. Nph. Nephridium. Nphm. Neplirostome. Nphm. D. 

 Dorsal lip of nephrostome. Nphm. V. Ventral lip of neplirostome. N. Sh. 

 Nerve-sheath. Niic. Or. Nuchal groove. Ntic. N. Nerve to nuchal groove. 

 N. N. Neural vessels. 0. cilv. Outer alveolar layer of giant-cell. Oc. Eyes. 

 CE. (Esophagus. CB. Comm. Circumoesophageal nerve-connectives. CE. Lat. 

 Lateral oesophageal vessel. 01. Otocyst. 0th. Otoliths. Ot. N. Nerve to 

 otocyst. Od. Proc. Process of ovary. Par. V. Parietal vessels. Per. Peri- 

 stomium. Proc. Process of crotchet. Prost. Prostomium. Prod. Epith. 

 Prostomial epithelium. Prost. Lat. Lateral process of prostomium. Prost. 

 Mid. Middle lobe of prostomium. Prost. Muse. Muscles of prostomium. 

 Prost. Sens. Sensory cells of prostomium. Riid. Br. Rudimentary gill on the 

 tail of A. cristata. Sen. C. Sensory cells. Sp. Septum. Sup. C. Support- 

 ing cells of the otocystic epithelium. F. Veutricle of heart. F. ]\f. Vitelline 

 membrane. V. Nph. Ventral lip of nephridium. V. V. Ventral vessel. 



PLATE 22. 



Fig. L — The large American specimen of A. cristata from the Harvard 

 Museum, seen from the left side to show the external features, setse, gills, 

 nephridiopores, and the segmentally arranged processes on the tail. There 

 are six nephridiopores on the left side and seven on the right side of this 

 specimen. The neuropodia of the first four segments are not visible exter- 

 nally. The cirriform processes of the tail are also shown on PI. 24, Eigs. 

 30—32. X f. 



Fig. 2. — Dorsal view of the anterior of a specimen of A. cristata, 300 

 mm. long, from Naples, to show the prostomium and nuchal organ and the 

 papillae of ihe buccal mass. X 4. 



Fig. 3. — A large specimen of A.Grubii from Port St. Mary, Isle of Man, 

 seen from the left side to show the external features, sette, gills, and ne- 

 phridiopores (5 in number), x 1^. 



Fig. 4. — A large specimen of A. ecaudata from Port St. Mary, to- show 

 the external features, setse, gills, and nephridiopores (13 in number), x 1^. 



Fig. 5. — Two views of the anterior end of A. Grubii from Port St. Mary, 

 showing the prostomium and nuchal organ. 



Fig. 5 a. — From the dorsal surface. X 3. 



Fig. 5 b. — From the left side, x 3. 



The anterior end of A. ecaudata closely agrees with this. 



Fig. 6. — Posterior end of a specimen of A. Grubii from Jersey, showing 

 the setae and developing gills, x 6. 



