10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, III 



only the ventral lower jaw and fangs are protruded. In the Nerei- 

 morpha (as restricted by the exclusion of these) the pharynx is 

 cylindrical and is often far protrusible, reaching its greatest length 

 and protrusibility in the Glyceridae and the Goniadidae, which because 

 of their unique conical, secondarily annulated prostomium, might 

 well constitute a suborder, the Glycerimorpha. This long, cylindrical, 

 far protrusible proboscis the writer regards as a high specialization. 



THE STOMATOGASTRIC NERVOUS SYSTEM IN POLYCHAETS 



A visceral nervous system has been known since the time of 

 Stannius (1831), who investigated that of Amphinome rostrata and 

 showed that the stomatogastric nerves issued both from the brain and 

 from the first ganglia on the perioesophageal connectives. Pruvot 

 (1885) showed that such a system occurs generally in the polychaets, 

 the nerves issuing in different cases either only from the brain as in 

 Eunice, or both from the brain and from the oesophageal connective 

 as in Nephthys and Phyllodoce, or only from the perioesophageal 

 ring as in Ophelia. A double origin has also been shown by Rodhe 

 (1887) for the Aphroditidae (Polynoe), viz, from the brain and 

 from the first perioesophageal ganglion. In Nereis according to 

 Hamaker (1898) and Holmgren (1916) the innervation is from the 

 brain and from the suboesophageal ganglion. The visceral nervous 

 system of Eunice, described in considerable detail by Heider, and 

 that of Hermione described by Bernert, are faily closely comparable 

 with one another. In all cases there are two pairs of stomatogastric 

 nerves, one pair of which arises in the fore-brain near the midline. 

 It therefore is probable that all are inherited from the primitive 

 polychaet. 



So far as the writer is aware the origin of the visceral nervous 

 system has not been determined or even deduced. Heider remarked 

 upon its individuality in opposition to the remaining part of the 

 nervous system ; and he concluded that it had a separate origin. 



INTERRELATIONS OF THE STOMODEUM, THE VISCERAL 



NERVOUS SYSTEM, AND THE BRAIN IN THE 



ANCESTRY OF EUNICE 



The purpose of this paper is to show how closely related, in the 

 writer's view, are the stomodeum, the visceral nervous system, and 

 the brain ; and how strongly a parallel evolution of all three is sug- 

 gested by the anatomy of Eunice. 



The compound stomodeal system (of oesophagus and pharynx) 



