Notes on the morphology of the Tunicata. 503 



d . 

 \ e d' 



J . — '■=" - i"- few K 





Fig. D. A cross section through one of the accessory glands of Ascidia atra Les., 

 at a point marked IV in Text-Fig. A. ^ 100 diameters. Reference letters as in Text- 

 Fig. A. 



The chief ciliated funnel in this species is well developed and has 

 the characteristic horse-shoe form (Text-Fig. A). It lies to the right of 

 the median line with the horos of the horse-shoe turned to the right. 



It is noteworthy that one of the great nerves arising from the 

 back of the brain is richly gangliated while the other is only 

 slightly so. 



The posterior end of the neural gland pushes up along the right 

 side of the ganglion, much as it does in A. menkda, and from its 

 upper posterior point a delicate duct continues backward along the 

 less gangliated nerve. A large, richly gangliated branch from the 

 gangliated nerve comes to lie in the median line not far from this 

 posterior prolongation of the duct. Further back the duct associates 

 itself with this median gangliated nerve, and, from the resemblance to 

 the arrangement in A. mentula, I do not doubt that the two run down 

 into the dorsal raphe, although I have had insufficient material to 

 determine this point. 



The chief interest in this species attaches to the peculiar condition 

 of the duct of the neural gland with its accessory glands, lateral 

 branches and accessory funnels. 



JPhallusia ttiammillata Cuv. 



Plate 34, Fig. 5. 

 JuLiN has well described the neural gland of Phallusia mammil- 

 lata 1). I fully confirm his description , and desire here only to call 

 attention to certain comparisons with Ascidia atra. Both species 



l)^Cf. JULIN, 1881. 



