196 RESEARCHES IN HELMINTHOLOGY AND PARASITOLOGY. 



1.5 to t.875 wide; posterior segments 0.75 long by i mm. wide. 

 (Drawing.) 



A number of specimens from the stomach of the Rock Bass, Af/i- 

 hlopiitcs rupestris. Lake George, New York. 



This species resembles the Tcenia oallata Rudolphi of the Euro- 

 pean Perch, Perca fluviatilis , and perhaps is the same. (Drawing.) 



Icenia Microptcri. — Head large, compressed spheroidal, with four 

 subterminal spherical bothria and a papilliform unarmed summit : 

 neck none ; body obscurely segmented, and with no obvious internal 

 organs, posteriorly variably narrowed and obtusely rounded at the 

 end. Length from half an inch to an inch, and about i mm. wide. 

 Apparently a larval form ; found in the body cavity of the Black Bass, 

 Micropterns nigricans. Six worms, soft, white, and active. The 

 longer ones of an inch would elongate to double the length, becom- 

 ing proportionately narrower. The head, about i mm. or more in 

 diameter, varied in length and breadth, according to contraction, 

 sometimes one and sometimes the other being the larger. Lake 

 George, N. Y. 



Last .summer while at Mt. Desert, Me., I examined a squid, Om- 

 mastrephes illeccbrosa, with the hope of finding the singular parasite 

 Dicycma. The specimen was in bad condition, and while I found none 

 of the latter, I obtained from it .several small worms, which I sup- 

 pose to be the larval form of a cestode. They were yet quite active 

 though the host was already putrescent. I suspected them to belong 

 to Tctrabothriorhynchns migratorius, observed in European cephalo- 

 pods, but examination showed them to be different. They moved 

 so actively and incessantly, contracting, expanding, and writhing, 

 that it was difficult to obtain a clear idea of the .shape of the worm. 

 It appears most nearly related with Ticnia, and pro\isionally may 

 be regarded as a larval form of this genus. Its more evident char- 

 acters may be summed up as follows : 



Tcpnia loligiiiis. — Head unarmed, without rostellum, quadrilobate, 

 continuous with the neck, which is variably long and narrow or short 

 and irregularly contracted and expanded, and is constricted from the 

 body. Lobes of the head elliptical, contractile and expansile and 

 becoming variably folded or corrugated, furnished each at the upper 

 pole with a hemispherical bothria. Body about as long as the head 

 and neck, extensile and contractile, obconic or obovate, compressed, 

 acute posteriorly, unsegmented. No interior organs visible except 

 a vessel along the sides of the neck and encircling the lobes of the 

 head. Color white. Length to about half an inch ; width about 



