PEROPHORA ANNECTENS. 59 



Another point that adds weight to the interpretation 

 adopted is found in the fact that close examination does 

 not discover in the knobs any of the cellular structure 

 characteristic of the normal tentacle, and I believe that 

 there is a thin ectosarc on the outermost surface of 

 the knob; though of this I am not fully satisfied. 



This view of the matter would seem to make the or- 

 ganism allied to the genus Podophrya as defined by Kent 

 ('8i-'82, vol. ii, pp. 806 and 813). 



However, more study of the animal will be necessary 

 to fully determine its atiinities. I have not seen any liv- 

 ing specimens. Onl}^ a small number of the infected 

 colonies have been found, and these were all in my col- 

 lection of preserved material. 



b. THE BRANCHIAL BASKET PROPER. 



As seen by fig. 3, pi. i, the long axes of the stigmata take 

 the direction of the curved antero-posterior axis of the 

 branchial sac as a whole. The convergence of the circles 

 of the transverse vessels on the dorsal side, already men- 

 tioned, produces the effect that the stigmata are longest 

 at the ventral, or endostylar side of the branchial sac, and 

 become gradually shorter toward the dorsal side. 



The papilla; of the transverse vessels are easily seen 

 through the walls of the body when the animal is removed 

 from the test and viewed by transmitted light (fig. 3 i-p-)- 

 There are from about six to eight on each half of each 

 transverse vessel, making on the average about one papilla 

 for each two stigmata, though the first in each row from 

 the median dorsal line is removed five, or six, or more 

 stigmata from this line, and are farther from this line 

 than are the first ones on the ventral side from the en- 

 dostyle. The middle papilke of each series on each side 

 of the body are somewhat larger than those nearer the 



