504 MAYNARD M. METCALF, 



have many branches from the duct, ending in accessory funnels. In 

 PA, mammillata these funnels are somewhat smaller than in A. atra 

 and are surrounded by a mass of cells containing red pigment. 



The chief ciliated funnel, the dorsal tubercle, is very small and 

 cannot always be distinguished, except by its position, from the ac- 

 cessory funnels. Its aperture is always irregular. Herdman^) de- 

 scribes specimens in which the dorsal tubercle is wholly absent. In 

 no other species of Tunicata, so far as I know, is the tubercle ever 

 wanting. 



In Phallusia there are large accessory glands along the course 

 of the duct, much larger than in Ascidia atra, forming almost a 

 continuous glandular mass along the whole of the branched portion 

 of the duct. The glandular tissue is formed by outgrowths from 

 the main duct and from its many branches. The presence of the 

 great amount of accessory glandular tissue may account for the 

 fact that the neural gland proper is much smaller than in Ascidia 

 atra. The great blood sinus of the dorsal lamina follows the course 

 of the duct and furnishes a rich blood supply for these accessory 

 glands. 



In the posterior region of the ganglion and gland the relations 

 are about as described for Ascidia atra. A posterior prolongation of 

 the duct of the gland (r. ^) runs up on the right side of the ganglion 

 and extends backward along the right posterior nerve. This duct 

 soon disintegrates, its cells no longer enclosing a lumen. These 

 irregularly arranged cells associate themselves with the fibres of the 

 rapheal nerve, becoming its ganglion cells. 



In Ascidia mentula I described a cord of ganglion cells arising 

 from the postero-dorsal region of the brain and running back to join 

 the rapheal duct. In the same region in Phallusia mammillata there 

 arises from the brain a hollow, tubular cord of cells (g. c) which bends 

 dorsally 'and forward, ending bhndly above the brain. It has no 

 connection with any of the other structures described. It seems to 

 be homologous with the gangliated cord of Ascidia mentula^). 



Observe that the ganglion cells of the rapheal nerve in Phallusia 

 are derived from a prolongation of the gland, not from the ganglion. 

 Reference will be made again to this point. 



1) Cf. Heedman, 1883. 



2) JuLiN does not mention the structures described in this and the 

 preceding paragraph. 



