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DISCOVERY REPORTS 



adopt Ridewood's orientation, so that in the following account the long axis of the body 

 is regarded as longitudinal (Fig. 5). 



The internal anatomy of Cephalodisciis has been worked out very thoroughly by 

 Harmer (1905) and Andersson (1907). From sections of the zooids of different species 



TRANSVERSE 



Fig. 5. Orientation of the zooid. a, proboscis; b, central 

 nervous system; c, gonad; d, notochord; c, post-oral 

 lamella; /, stomach; g, intestine; /?, pharynx; ?', stolon; 

 j, heart and pericardium. 



of the present collection it has been possible to verify these results. The following 

 account does not attempt to give a complete description of all parts, but only deals with 

 those organs and systems about which new observations have been made. 



PROBOSCIS 



The proboscis of Cephalodisciis varies in size and shape, as will have been seen in the 

 systematic accounts. The discoidal part of the proboscis is attached to the body by a 

 very short neck, which is always capable of a little extension. That this gives the disc 

 great mobility is clear from the diverse positions of the proboscis in the preserved 

 individuals. Observations made on the living zooids show that they come out of the 

 coenoecium and creep on the surface of the colony, with the disc acting as a sucker. 

 This was first recorded by Andersson (1907, p. 59) and confirmed by the observations 

 of Dr Stanley Kemp during the present expedition. The disc is flattened dorso-ventrally. 



