On Sticbocotyle nopliropis Cuiiiiin^liam, a parasite uf the AmcricuD lobster. 477 



region of body, dorsal, cue upou either side of intestine, left a little 

 farther anterior than rif;ht. Ovary nearly median, ventral of intestine, 

 in front of testes; oviduct passing forward on right side. Vitellary 

 glands on dorsal side of intestine near posterior end of body, duct 

 passing down around right side of intestine to oviduct. Excretory 

 pore, dorsal, near i)osterior end of i)ody. Excretory vesicle, forming 

 two bread convoluted tubular trunks which extend forward on either 

 side of intestine to region of pharynx. Larval form encysted in wall 

 of intestine of the larger marine Crustacea. Adult form unknown. 



StU'hocotylc nephropis Cunn. 



in cysts in intestinal wall of Nephrops and Ilomarus. 



Life History. 



The life history of Siichocotyle is entirely unknown. Cunningham 

 thought that the adult would probably be found to live inside the 

 body of some large fish. This is rendered extremely probable both 

 by the fact that Macras2)is and Cotylogaster are found in such ani- 

 mals, and also by the fact that lobsters are said to be eagerly eaten 

 by many of the larger fishes during^ the early summer after the moult 

 has occurred. Both the position of the sexual apparatus and the 

 l)resence of sense organs in the worms which were obtained in the 

 hitter part of June suggests that they were ready for life under other 

 conditions. 



I am told by the lobster-fishermen upon the coast of Maine that 

 the large sea cat-fish will often enter lobster-pots and devour the 

 hard-shelled lobsters which are contained in them. I think it not 

 improbable, therefore, that this fish may become the final host of 

 Stichocotyle. I have been able to obtain only a very few specimens 

 of this fish for examination, and so have not succeeded in satis- 

 factorily testing my hypothesis. I hope to be able to examine a con- 

 siderable number of sharks and cat-fishes during the present summer, 

 in the expectation of obtaining the adult Stichocotyle. 



Concerning the early life history of Stichocotyle., we have even 

 less to guide our conjectures. That tlie nearly related Aspidogaster 

 has a direct development with metamorphosis, cannot safely be taken 

 as an indication that Stichocotyle has also a direct development, for 

 lowing to the well known tendency of fresh-water conditions to ob- 

 iterate larval life, it may well be that Aspidogaster has secondarily 



