448 W ^- NICKERSON. 



at once take the time to investigate them , the infected part oï the 

 intestinal tract was cut out and placed in preservative fluid until I 

 should be able to give it a more thorough examination. Upon opening 

 these cysts each one was found to contain coiled up within it a small 

 worm agreeing very closely with the description given by J. T. Cun- 

 ningham ('84) of a Trematode which he found in a similar position 

 in the Norwegian lobster, Nephrops, and which he named from the 

 immature encysted forni Stichocotyle nephropis. 



It has not been reported heretofore from the American lobster, 

 Homarus americanus, and in tact the paper of Cinningham already 

 alluded to is the only original reference to the genus. Cunningham 

 deals in this paper with the immature worms, which he found in the 

 cysts, and gives a general description of their form, together with 

 such facts of their anatomy as he was able to make out in his spe- 

 cimens. The sexually mature form has not yet been discovered. 

 Monticelli ('93) declines to recognize the genus Stichocotyle, since 

 only the larval stage is known and its resemblance to Macraspis 

 elegans described by Olsson ('69) is so great as to make it probable 

 that it is only the immature form of Macraspis. The worm seemed 

 to me to possess unusual interest because of its peculiarities of form 

 and structure, and 1 therefore determined to investigate it further in 

 the hope that I might be able to find out something of its life-history, 

 possibly to discover the adult animal, and also to obtain a more ad- 

 equate knowledge of the finer anatomical features of the larval stage. 



In order to carry on this investigation it was necessary that I 

 should have the opportunity to examine a large number of uncooked 

 lobsters, an opportunity which I couUl nowhere else get so well as at 

 a lobster canning establishment. Mr. Arthur A. Bkowne, manager 

 of the canning factory at North Haven, Maine, very kindly ofiered 

 me all the privileges which I wished, and I accordingly spent several 

 days during the latter part of June 1893 at his factory. I would 

 here make the acknowledgements due to Mr. Browne for the courtesies 

 so freely extended to me. 



1 examined at North Haven between 400 and 500 lobsters and 

 obtained from them the greater part of the material which 1 have 

 used in the study of this worm. I was surprised to find so few cases 

 of infection ; out of ail the lobsters opened I found only 5 or (J at 

 all infected and only oni' of these showed more than 4 or 5 cysts; 

 that one had 27. In all cases the jtart of the intestinal tract atl'ccted 

 was the same, viz. the region immediately adjacent to tlic point of 



