ANATOMY OF ARENIOOLA ASSIMILTS. 78 J 



1900. Child, C. ;M. — 'Arcliiv f. Eutwickelungsniechanik,' Baud ix, p. 587, 

 1900. 



1900. Gamble, F. W., and Asiiworth, J. H. — ' Quart. Journ. Micr. Sci.,' 



xliii, p. 419, 1900. 



1901. Pratt, E. M. — 'Memoirs and Proceedings of the Manchester Lit. and 



Phil. Society,' vol. xlv, p. 12, 1901. 

 1901. Johnson, H. P. — 'Proceedings of tiie Boston Society of Natural His- 

 tory,' vol. xxix, p. 421, 1901. 



1901. EiiLERS, E. — 'Die Polychseten des magellanischen und chilenischen 

 Strandes,' pp. 177, 178, Berlin, 1901. 



EXPLANATION OF PLATES 36 & 37, 



Illustrating Dr. J. H. Ashworth's memoir on "The Anatomy 

 of Arenicola as si mi lis, Ehlers, and of a New Variety 

 of the Species, with someObservations on the Post- 

 larval Stages. 



List of Reference Letters. 



A.B.S. Achaetous segment of body between peristomium and first 

 clisetigerous segment. Ant. Cer. L. Anterior lobe of brain. Bl. Bladder of 

 nephridium. B.V. Blood-vessel. C. Cuticle. Ch.Seg! First chsetigerous 

 segment. Coil. Ccelom. Conn. Tiss. Connective tissue. Epid. Epidermis. 

 E. T. Entrance to tube leading from otocyst to exterior. E-vt. Op. 01. External 

 opening of otocyst. Gang.C. Ganglion-cell. Gad. Lai. Lateral gastric 

 vessel. Ql. C. Gland cell. Gon. Gonad. Gon. F. Gonidial vessel, lit. 

 Heart. Met.Gr. Metastomial groove. Middle Comm. Middle commissure 

 of brain. j\I.Circ. Circular muscles. M.Long. Longitudinal muscles. Mo. 

 Mouth. M.Sh. Bncc. Muscular sheath of buccal mass. N. Band of nerve- 

 fibres from prostomial epithelium to brain. N. Aff. Afferent vessel of 

 nephridium. N. Bucc. Nerve to buccal mass and papilla; of " proboscis." 

 N. C. Nerve-cord. N. Epid. Nerve to epidermis. Nm. Ch. Ncuropodial 

 chsetae. Not.S. Notopodial setaj. Nphm.D. Dorsal lip of ncphrostome. 

 Nphm.V. Ventral lip of nephrostome. Npile. Neuropile. Nitc. Gr. Nuchal 

 groove. Oc. Eye. CE. (Esophagus. CE. Conn. Esophageal connective. 

 (E. Gl. (Esophageal gland. Ot. Otocyst. 0th. Otolith. Ot. T. Tube of 

 otocyst. Fap. Papilla of " proboscis." Ter. Peristomium. Vh. Pharynx. 

 Post. Cer. L. Posterior lobe of brain. Frost. Prostomium. Frost. Epith. 

 Epitiudinm of prostomium. Frost, hat. Lateral lobe of prostomium. 

 VOL. 46, I'AKT 4. — NEW SERIES. EEE 



