28 University of California Publications in Zoology. [Vol. 4 



have been unable to find anything that can be identified as these 

 parts. A peculiar knot, with no definiteness of organization, was 

 present at the apex of the cone-shaped muscular body shown in 

 the figure with its apex truncated. This was connected by tat- 

 tered portions of tissue with the branchial membrane ; but I have 

 tried in vain to find anything in it that I could call gland, nerve 

 ganglion, or duct. I must therefore leave the question of these 

 parts almost as vague as that of the endostyle. The difference 

 is that I have not even found where the endostyle ougJit to he. 



The muscle bands in the figure are considerably stronger here 

 than elsewhere in the vicinity, and I have not been able to trace 

 the circular ones entirely around the circle of which they appear 

 to be a segment. As little have I been able to follow out the 

 entire course of the circular groove, g.i.f., beyond the tentacles 

 shown in the figure. No doubt can be entertained, however, that 

 this is a piece of the peripharyngeal band. It is laid off as the 

 figure shows into quite regular nodes by radiating cross grooves. 

 Whether these exist in nature or not, I do not know, but am in- 

 clined to believe they do. The complete circle of tentacles I have 

 not been able to find, the total number being calculated from the 

 segment of the circle present. The great number of minute pro- 

 cesses on the inner surface within the pharyngeal area, seen in 

 the figure, i^.i.f., will not escape the notice of the reader, nor will 

 they fail to excite curiosity as to their significance. I know of 

 nothing comparable to them in any other ascidian. 



I have spoken of the branchial sac as being without stigmata, 

 but as consisting of a network of delicate vessels. The criteria 

 applied in affirming that the irregular network of vessels con- 

 stituting the branchial sac (pi. 2, fig. 30) contains no true stig- 

 mata, are two. First, the absence of cilia which are held to be 

 characteristic of all true stigmata in Ascidians ; and second, the 

 absence of vessels situated on the inner surface of the web. This 

 last criterion would be valid only on the assumption that the web 

 should really be of the type presented by the genera related to 

 Corynascidia, namely, Ilypobythius, Abyssascidia, Corella, etc. ; 

 that is, that the vascular network present represents the "in- 

 ternal vessels" of the genera mentioned, the true stigmatic 

 membrane being unrepresented in the present species. The possi- 



