NOTES ON CE8TODE CYSTS, T.ENIA CHAMISSONII, NEW 

 SPECIES, FROM A PORPOISE. 



By Edwin Linton, 



Of Witfililitgton aniJ JeftWaon foJlrge. 



On October 7, 1901, Mr. Viual N. Edwards, of Woods Hole, Massa^ 

 chusetts, collected a lot of about twent3"-tive cysts from the mesentery 

 of a skunk porpoise {La«jenorhynchns acutux) captured at Menemsha 

 Bight, Vineyard Sound. 



This material, preserved in formalin, was sulmiitted to me in 

 August, 1903, at which time I made a preliminary examination of it. 

 Later some of it was stained and sectioned. 



I already had in my collection a few cysts from the same host which 

 were collected on an expedition from Woods Hole to the tile-tish 

 grounds, July 29, 1S99. 



In the older lot there were two kinds of cysts, one kind similar to 

 those of the later lot, and, like them, obtained from the body cavity. 

 The others were smaller, and according to the label, came from the 

 blubber. The scolex of one of these cysts was examined and proved 

 to l>e a PhyUohothriuin. 



It is with the larger cysts that this paper is especially concerned. 



These cysts are, for the most part, oblong-ovate and from 20 to 30 

 mm. in length. Their connective tissue walls are rather thick, and 

 are dense, tough, and leathery. Upon opening one of them a slender 

 filament, which may be as much as live or six times as long as the 

 cyst, is seen attached to the inner wall. One of these filaments in an 

 averaged-sized cyst measured 127 mm. in length and less than 1 nnn. 

 in diameter. 



At first sight these filaments might be mistaken for nematoid worms, 

 but a closer examination will show them to be the inverted portions of 

 a l)ladder worm (cysticercus). 



By careful manipulation the connective tissue layers of the cyst 

 may be removed and the contained bladder liberated. The outer wall 

 of the bladder is closely adherent to the inner wall of the cyst, and 

 the bladder itself is rather fragile in the preserved specimens. 



Proceedings U. S. National Museum, Vol. XXVIII— No. 1410. 



819 



