NERILLA AN ARCHIANNELID. 
397 
Nerilla an Archiannelid. 
By 
Edwin S. Goodrich. F.K.S.. 
Fellow of Merton College, Oxford. 
With Plates 38-41. 
Contents. 
page 
Introduction . . . . .397 
General Appearance and Habits .... 398 
External Morphology ..... 399 
The Epidermis, Nervous System, and Sense-Organs . . 402 
The Alimentary Canal ..... 404 
The Coelom and General Mesoblastic Tissues . . 405 
The Yascular System ..... 407 
The Muscular System ..... 407 
The Nepliridia ...... 408 
The Genital Organs of the Male ... 410 
The Genital Organs of the Female . 413 
The Morphology of the Genital Ducts . . 415 
The Body-cavity in the Arcliiannelids . 417 
The Affinities of Nerilla ..... 418 
Comparison of Nerilla with other Arcliiannelids 419 
Summary ...... 420 
Literature . . 422 
Introduction. 
The little worm which forms the subject of this paper was 
found by me in the month of May of last year, 1911, in one 
of the sea-water tanks of the Stazione Zoologica at Naples. 1 
On close inspection it turned out to be a member of that 
1 I wish here to express my thanks to the authorities of Cambridge 
University, who granted me the use of a table at Naples. 
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